Document Number: MMA51xxLW Rev. 1, 03/2014 Freescale Semiconductor Data Sheet: Technical Data Xtrinsic MMA51xxLW PSI5 Inertial Sensor MMA51xxLW The MMA51xxLW family, a SafeAssure solution, includes the AKLV27 and PSI5 Version 1.3 compatible overdamped Z-axis satellite accelerometers. Features Bottom View * * * * 60g to 480g Full-Scale Range Selectable 400 Hz, 3-Pole, or 4-pole Low-Pass Filter Single Pole High Pass Filter with Fast Startup and Output Rate Limiting PSI5 Version 1.3 Compatible - PSI5-P10P-500/3L Compatible - Programmable Time Slots with 0.5 s Resolution - Selectable Baud Rate: 125 kBaud or 190.5 kBaud - Selectable Data Length: 8 or 10 bits - Selectable Error Detection: Even Parity, or 3-bit CRC - Optional Daisy Chain with External Low-Side Switch - Two-Wire Programming Mode * 16 s Internal Sample Rate, with Interpolation to 1 s * Pb-Free 16-Pin QFN, 6 x 6 Package * Qualified AECQ100, Revision G, Grade 1 (-40C to +125C) (http://www.aecouncil.com/) 16-PIN QFN CASE 2086-01 VBUF TEST BUS_SW VSSA Top View 16 15 14 13 Typical Applications VCC 1 * Airbag Front and Side Crash Detection 12 VSSA 17 VSS 2 11 VREGA IDATA 3 Range Package Shipping MMA5106LW Z 60g 2086-01 Tubes MMA5112LW Z 120g 2086-01 Tubes MMA5124LW Z 240g 2086-01 Tubes MMA5148LW Z 480g 2086-01 Tubes MMA5106LWR2 Z 60g 2086-01 Tape & Reel MMA5112LWR2 Z 120g 2086-01 Tape & Reel MMA5124LWR2 Z 240g 2086-01 Tape & Reel MMA5148LWR2 Z 480g 2086-01 Tape & Reel (c) 2014 Freescale Semiconductor, Inc. All rights reserved. 7 8 DIN Axis 6 DOUT Device 5 SLCK ORDERING INFORMATION 9 VREG PCM VSS 10 CS 4 PIN CONNECTIONS VVBUF VBUF VCC VREG IDATA VREGA C4 C5 C6 VCE R1 R2 MMA51xx C2 C1 VSSA CS SCLK VSS VSS DO Note: Pin names and references may differ from PSI5 V1.3 pin names and references C3 R3 M1 BUS_SW DI Optional for Daisy Chain PCM VSS_OUT Figure 1. Application Diagram Table 1. External Component Recommendations Type Description C1 Ceramic 2.2 nF, 10%, 50V minimum, X7R VCC Power Supply Decoupling and Signal Damping C3 Ceramic 470 pF, 10%, 50V minimum, X7R IDATA Filtering and Signal Damping C2 Ceramic 15 nF, 10%, 50V minimum, X7R VCC Power Supply Decoupling C4, C5, C6 Ceramic 1 F, 10%, 10V minimum, X7R Voltage Regulator Output Capacitor(s) R1 General Purpose 82, 5%, 200 PPM VCC Filtering and Signal Damping R2 General Purpose 27, 5%, 200 PPM IDATA Filtering and Signal Damping R3 General Purpose 20 k, 5%, 200 PPM M1 N-Channel MOSFET -- xxxxxxx xxxxxxx Z: 0g Z: 0g xxxxxxx xxxxxxx xxxxxxx xxxxxxx Ref Des Z: 0g Purpose Gate Resistor for External Low-Side Daisy Chain FET Low-Side Daisy Chain Transistor xxxxxxx xxxxxxx Z: 0g Z: +1g Z: -1g EARTH GROUND Figure 2. Device Orientation Diagram MMA51xxLW 2 Sensors Freescale Semiconductor, Inc. VCC Buffer Voltage Regulator Reference Voltage VBUF VBUF VREF Digital Voltage Regulator VREG Analog Voltage Regulator VREGA CS VREG VREGA VBUF VSSA SCLK Low Voltage Detection SPI DIN Sync Pulse Detection Control Logic DOUT VCC Programming Interface IDATA OTP Serial Encoder Array VSS Daisy Chain Switch Driver BUS_SW VREG Self-Test Interface VREGA VREG Control In Status Out DSP g-cell Converter SINC Filter IIR LPF Compensation Offset Monitor HPF PCM Encoder PCM Figure 3. Internal Block Diagram MMA51xxLW Sensors Freescale Semiconductor, Inc. 3 VBUF TEST BUS_SW Pin Connections VSSA 1 16 15 14 13 VCC 1 12 VSSA 17 VSS 2 11 VREGA IDATA 3 10 CS 5 6 7 8 SLCK DOUT DIN 9 VREG PCM VSS 4 Figure 4. Top View, 16-Pin QFN Package Table 2. Pin Description Pin Pin Name Formal Name Definition 1 VCC Supply This pin is connected to the PSI5 power and data line through a resistor and supplies power to the device. An external capacitor must be connected between this pin and VSS. Reference Figure 1. 2 VSS Digital GND 3 IDATA Response Current 4 VSS Digital GND 5 PCM PCM Output This pin provides a 4 MHz PCM signal proportional to the acceleration data for test purposes. The output can be enabled via OTP. Reference Section 3.5.3.7. If unused, this pin must be left unconnected. 6 SCLK SPI Clock This input pin provides the serial clock to the SPI port for test purposes. An internal pulldown device is connected to this pin. This pin must be grounded or left unconnected in the application. 7 DOUT SPI Data Out This pin functions as the serial data output from the SPI port for test purposes. This pin must be left unconnected in the application. 8 DIN SPI Data In This pin functions as the serial data input to the SPI port for test purposes. An internal pulldown device is connected to this pin. This pin must be grounded or left unconnected in the application. 9 VREG Digital Supply This pin is connected to the power supply for the internal digital circuitry. An external capacitor must be connected between this pin and VSS. Reference Figure 1. 10 CS Chip Select This input pin provides the chip select to the SPI port for test purposes. An internal pullup device is connected to this pin.This pin must be left unconnected in the application. 11 VREGA Analog Supply This pin is connected to the power supply for the internal analog circuitry. An external capacitor must be connected between this pin and VSSA. Reference Figure 1. 12 VSSA Analog GND 13 VBUF Power Supply 14 TEST Test Pin 15 BUS_SW Bus Switch Gate Drive 16 VSSA Analog GND PAD Die Attach Pad Corner Pads Corner Pads 17 This pin is the power supply return node for the digital circuitry. This pin is connected to the PSI5 power and data line through a resistor and modulates the response current for PSI5 communication. Reference Figure 1. This pin is the power supply return node for the digital circuitry. This pin is the power supply return node for the analog circuitry. This pin is connected to a buffer regulator for the internal circuitry. The buffer regulator supplies both the analog (VREGA) and digital (VREG) supplies to provide immunity from EMC and supply dropouts on VCC. An external capacitor must be connected between this pin and VSS. Reference Figure 1. This pin is must be grounded or left unconnected in the application. This pin is the drive for a low-side daisy chain switch. When daisy chain mode is enabled, this pin is connected to the gate of an n-channel FET which connects VSS to VSS_OUT. Reference Figure 1. If unused, this pin must be left unconnected. This pin is the power supply return node for the analog circuitry. This pin is the die attach flag, and is internally connected to VSS. Reference Section 7 for die attach pad connection details. The corner pads are internally connected to VSS. MMA51xxLW 4 Sensors Freescale Semiconductor, Inc. 2 Electrical Characteristics 2.1 Maximum Ratings Maximum ratings are the extreme limits to which the device can be exposed without permanently damaging it. # Rating 1 2 3 Supply Voltage (VCC, IDATA) Reverse Current 160 mA, t 80 ms Continuous Transient (< 10 s) 4 VBUF, Test, BUS_SW 5 VREG, VREGA, SCLK, CS, DIN, DOUT, PCM 6 Powered Shock (six sides, 0.5 ms duration) 7 8 Symbol Value Unit VCC_REV VCC_MAX VCC_TRANS -0.7 +20.0 +25.0 V V V (3) (3) (9) -0.3 to +4.2 V (3) -0.3 to +3.0 V (3) gpms 2000 g (3) Unpowered Shock (six sides, 0.5 ms duration) gshock 2500 g (3) Drop Shock (to concrete, tile or steel surface, 10 drops, any orientation) hDROP 1.2 m (5) 9 10 11 12 Electrostatic Discharge (per AEC-Q100) External Pins (VCC, IDATA, VSS, VSSA), HBM (100 pF, 1.5 k) HBM (100 pF, 1.5 k) CDM (R = 0 ) MM (200 pF, 0 ) VESD VESD VESD VESD 4000 2000 1500 200 V V V V (5) (5) (5) (5) 13 14 Temperature Range Storage Junction Tstg TJ -40 to +125 -40 to +150 C C (3) (9) 15 Thermal Resistance JC 2.5 C/W (9,14) 2.2 Operating Range VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified. # 16 17 18 Characteristic Supply Voltage Programming Voltage (IDATA 85 mA) Applied to IDATA, VCC Symbol VL 4.2 Typ Max Units V V (1) (9) VCC VCC_UV VVCC_UV_F -- -- VH 17.0 VL VPP 14.0 -- -- V (3) TA TA TL -40 -40 TH +105 +125 C C (1) (3) Operating Temperature Range 19 20 Min MMA51xxLW Sensors Freescale Semiconductor, Inc. 5 2.3 Electrical Characteristics - Supply and I/O VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified. # Characteristic Symbol Min Typ Max Units 21 Quiescent Supply Current * IIDLE 4.0 8.0 mA (1) 22 Modulation Supply Current * IMOD IIDLE+ 22.0 IIDLE+ 26.0 IIDLE+ 30.0 mA (1) 23 Inrush Current (Power On until VBUF, VREG, VREGA Stable) IINRUSH 30 mA (3) 24 25 26 Internally Regulated Voltages VBUF VREG VREGA VBUF VREG VREGA 3.60 2.425 2.425 3.80 2.50 2.50 4.00 2.575 2.575 V V V (1) (1) (1) VVCC_UV_F VBUF_UV_F VREG_UV_F VREGA_UV_F 3.40 2.95 2.15 2.15 3.70 3.15 2.25 2.25 4.0 3.35 2.35 2.35 V V V V (3, 6) (3, 6) (3, 6) (3, 6) VCC_HYST VBUF_HYST VREG_HYST VREGA_HYST 0.10 0.05 0.05 0.05 0.25 0.10 0.10 0.10 0.40 0.15 0.15 0.15 V V V V (3) (3) (3) (3) ESR 500 0 1000 1500 200 nF m (9) (9) VIDLE VSYNC VIDLE+1.4 VIDLE+2.0 15.4 VIDLE+2.6 V V (3, 11) (3, 6) ISYNC_PD IMOD - IIDLE mA (3) * * * 31 32 33 34 Low Voltage Detection Threshold VCC Falling VBUF Falling VREG Falling VREGA Falling Hysteresis VCC VBUF VREG VREGA 35 36 External Capacitor (VBUF, VREG, VREGA) Capacitance ESR (including interconnect resistance) 37 38 Synchronization Pulse (See Figure 5) VIDLE Voltage Range DC Sync Pulse Detection Threshold 39 Sync Pulse Pulldown Current 40 Output High Voltage (DO) ILoad = 100 A VOH VREG - 0.1 V (9) 41 Output Low Voltage (DO) ILoad = 100 A VOL 0.1 V (9) 42 Input High Voltage CS, SCLK, DI VIH 0.7 * VREG V (9) 43 Input Low Voltage CS, SCLK, DI VIL 0.3 * VREG V (9) 44 45 Input Current High (at VIH) (DI) Low (at VIL) (CS) IIH IIL -100 10 -10 100 A A (9) (9) 46 Pulldown Resistance (SCLK) RPD 20 100 k (9) 47 BUS_SW Output High Voltage (BUS_SW) ILoad = 100 A VBUS_SW_OH 3.15 VBUF V (9) 48 Output Low Voltage (BUS_SW) ILoad = 100 A VBUS_SW_OL 0.0 0.45 V (9) 49 Daisy Chain Addressing Mode Sync Pulse Period tS-S_PM_L s (7) 50 Bus Switch Output Activation Time (C = 50 pF) From last bit of "SetAdr" Response to 80% of VBUS_SW_OH 300 s (7) 51 Sync Pulse Blanking Time after "SetAdr" Command Received From last bit of "SetAdr" Response s (7) 27 28 29 30 * * tBUS_SW tDC_BLANKING 200000 / fOSC MMA51xxLW 6 Sensors Freescale Semiconductor, Inc. 2.4 Electrical Characteristics - Sensor and Signal Chain VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified. # Characteristic Symbol Min Typ Max Units * * * * SENS SENS SENS SENS -- -- -- -- 8 4 2 1 -- -- -- -- LSB/g LSB/g LSB/g LSB/g (1) (1) (1) (1) * * SENS_240 SENS_240 SENS_240 SENS_480 SENS_480 SENS_480 -5 -7 -7 -5 -7 -7 -- -- -- -- -- -- +5 +7 +7 +5 +7 +7 % % % % % % (1) (1) (9) (1) (1) (9) * OFF10Bit OFF10Bit -52 -52 0 0 +52 +52 LSB LSB (1) (9) * * OFF10Bit OFF10Bit -1 -2 0 0 +1 +2 LSB LSB (1) (9) 56 57 58 59 60 61 Sensitivity (10-bit output @ 100 Hz, referenced to 0 Hz) 60g Range 120g Range 240g Range 480g Range Total Sensitivity Error (including non-linearity) TA = 25C, 240g TL TA TH, 240g TL TA TH, 240g, VVCC_UV_F VCC VL TA = 25C, > 240g TL TA TH, > 240g TL TA TH, > 240g, VVCC_UV_F VCC VL 62 63 Digital Offset Before Offset Cancellation 10-bit 10-bit, TL TA TH, VVCC_UV_F VCC VL 64 65 Digital Offset After Offset Cancellation 10-bit, 0.3 Hz HPF or 0.1 Hz HPF 10-bit, 0.04 Hz HPF 66 Continuous Offset Monitor Limit 10-bit output, before compensation OFFMON -66 +66 LSB (3) 67 Range of Output (10-Bit Mode) Acceleration RANGE -480 +480 LSB (3) 68 69 Cross-Axis Sensitivity X-axis to Z-Axis Y-axis to Z-Axis * * VXZ VYZ -5 -5 +5 +5 % % (3) (3) 70 System Output Noise Peak (10-bit Mode, 1 Hz - 1 kHz, All Ranges) * nPeak -4 -- +4 LSB (3) 71 System Output Noise RMS (10-bit mode, 1 Hz - 1 kHz, All Ranges) * nRMS -- -- +1.0 LSB (3) 72 73 Non-linearity 10-bit output, 240g 10-bit output, > 240g NLOUT_240g NLOUT_480g -2 -2 +2 +2 % % (3) (3) 52 53 54 55 * * MMA51xxLW Sensors Freescale Semiconductor, Inc. 7 2.5 Electrical Characteristics - Self-Test and Overload VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified. # Characteristic Symbol Min Typ Max Units gST10_60Z gST10_120Z gST10_240Z gST10_480Z 120 40 35 12 280 160 153 94 LSB LSB LSB LSB (3) (3) (3) (3) 74 75 76 77 10-Bit Output During Active Self-Test (TL TA TH) 60g Range 120g Range 240g Range 480g Range 78 79 Acceleration (without hitting internal g-cell stops) 60g Range Positive 60g Range Negative gg-cell_Clip60ZP gg-cell_Clip60ZN 425 -1205 642 -720 980 -512 g g (9) (9) 80 81 Acceleration (without hitting internal g-cell stops) 120g Range Positive 120g Range Negative gg-cell_Clip120ZP gg-cell_Clip120ZN 425 -1205 642 -720 980 -512 g g (9) (9) 82 83 Acceleration (without hitting internal g-cell stops) 240g Range Positive 240g Range Negative gg-cell_Clip240ZP gg-cell_Clip240ZN 1450 -3100 2180 -2210 2800 -1800 g g (9) (9) 84 85 Acceleration (without hitting internal g-cell stops) 480g Range Positive 480g Range Negative gg-cell_Clip480ZP gg-cell_Clip480ZN 2200 -3700 2800 -3220 3300 -2780 g g (9) (9) 86 87 and Sinc Filter Clipping Limit 60g Range Positive 60g Range Negative gADC_Clip60ZP gADC_Clip60ZN 159 -334 238 -274 336 -216 g g (9) (9) 88 89 and Sinc Filter Clipping Limit 120g Range Positive 120g Range Negative gADC_Clip120ZP gADC_Clip120ZN 305 -693 433 -544 577 -414 g g (9) (9) 90 91 and Sinc Filter Clipping Limit 240g Range Positive 240g Range Negative gADC_Clip240ZP gADC_Clip240ZN 836 -1909 1178 -1566 1599 -1245 g g (9) (9) 92 93 and Sinc Filter Clipping Limit 480g Range Positive 480gZ Range Negative gADC_Clip480ZP gADC_Clip480ZN 1591 -3217 2014 -2856 2478 -2524 g g (9) (9) * * * * MMA51xxLW 8 Sensors Freescale Semiconductor, Inc. 2.6 Dynamic Electrical Characteristics - PSI5 VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified # Characteristic Symbol Min Typ Max Units tPSI5_INIT1 tPSI5_INIT2_10s tPSI5_INIT2_8s tPSI5_INIT2_10a0 tPSI5_INIT2_8a0 tPSI5_INIT3_10s tPSI5_INIT3_8s tPSI5_INIT3_10a0 tPSI5_INIT3_8a0 tOC1 tOC2 tST1 tST2 tST3 ST_RPT tPME 0 532000 / fOSC 256 * tS-S 288 * tS-S 512 * tASYNC 576 * tASYNC 2 * tS-S 2 * tS-S 19 * tASYNC 2 * tASYNC 320000 / fOSC 280000 / fOSC 128000 / fOSC 128000 / fOSC 128000 / fOSC 300000 / fOSC 5 s s s s s s s s s s s s s s s (7) (7) (7) (7) (7) (7, 12) (7, 12) (7, 12) (7, 12) (7) (7) (7) (7) (7) (7, 12) (7) tRS_PM tRS tS-S tSYNC tSYNC_LPF tSYNC_LPF_RST_ST tSYNC_LPF_RST tSYNC_OFF_500 tA_SYNC_DLY tPD_DLY tPD_ON tSYNC_JIT 58 tPSI5_INIT1 tSYNC_OFF 9 120 50 0 280 66 / fOSC 616 / fOSC 1810 / fOSC 74 / fOSC 64 / fOSC 600 2 / fOSC ms s s s s s s s ns s s s (7) (7) (7) (7) (9) (7) (7) (7) (9) (7) (7) (7) tBIT_LOW tBIT_HI 7.6000 4.9875 8.0000 5.2500 8.4000 5.5125 s s (7) (7) tRISE tFALL 324 324 463 463 602 602 ns ns (3) (3) 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 Initialization Timing Phase 1 Phase 2 (10-Bit, Synchronous Mode, k = 4) Phase 2 (8-Bit, Synchronous Mode, k = 8) Phase 2 (10-Bit, Asynchronous Mode 0, k = 8) Phase 2 (8-Bit, Asynchronous Mode 0, k = 16) Phase 3 (10-Bit, Synchronous Mode, ST_RPT = 0) Phase 3 (8-Bit, Synchronous Mode, ST_RPT = 0) Phase 3 (10-Bit, Asynchronous Mode 0, ST_RPT = 0) Phase 3 (8-Bit, Asynchronous Mode 0, ST_RPT = 0) Offset Cancellation Stage 1 Operating Time Offset Cancellation Stage 2 Operating Time Self-Test Stage 1 Operating Time Self-Test Stage 2 Operating Time Self-Test Stage 3 Operating Time Self-Test Repetitions Programming Mode Entry Window 110 111 112 113 114 115 116 117 118 119 120 121 Synchronization Pulse (Figure 5, Figure 28 and Figure 32) Reset to first sync pulse (Program Mode Entry) Reset to first sync pulse (Normal Mode) Sync Pulse Period Sync Pulse Width Sync Pulse Reference LPF time constant Sync Pulse Reference Discharge Start Time Sync Pulse Reference Discharge Activation Time Sync Pulse Detection Disable Time (BLANKTIME = 0) Analog Delay of Sync Pulse Detection Sync Pulse Pulldown Function Delay Time Sync Pulse Pulldown Function Activate Time Sync Pulse Detection Jitter 122 123 Data Transmission Single Bit Time (PSI5 Low Bit Rate) Data Transmission Single Bit Time (PSI5 High Bit Rate) 124 125 Modulation Current (20% to 80% of IMOD - IIDLE) Rise Time Fall Time 126 127 Position of bit transition (PSI5 Low Baud Rate) Position of bit transition (PSI5 High Baud Rate) * * tBittrans_LowBaud tBittrans_HighBaud 49 47 50 51 53 % % (7) (7) 128 Asynchronous Response Time * tASYNC 912 / fOSC s (7) 129 130 131 132 133 134 135 136 Time Slots Minimum Programmed Time Slot (TIMESLOTx = 0x001) Maximum Programmed Time Slot (TIMESLOTx = 0x3FF) Default Time Slot (TIMESLOTx = 0x000) Time Plot Resolution Sync Pulse to Daisy Chain Default Time Slot 1 Sync Pulse to Daisy Chain Default Time Slot 2 Sync Pulse to Daisy Chain Default Time Slot 3 Sync Pulse to Daisy Chain Programming Time Slot * tTIMESLOTx_MIN tTIMESLOTx_MAX tTIMESLOT_DFLT tTIMESLOTx_RES tTIMESLOT_DC1 tTIMESLOT_DC2 tTIMESLOT_DC3 tTIMESLOT_DCP 2 / fOSC 2046 / fOSC 186 / fOSC 2 / fOSC 186 / fOSC 768 / fOSC 1400 / fOSC 186 / fOSC s s s s/LSB s s s s (7, 9) (3, 7) (3, 7) (7) (7) (7) (7) (7) 137 138 139 140 Data Interpolation Latency (Figure 35, Figure 36) Data Setup Time - Synchronous Mode (Figure 36) Data Setup Time - Double Sample Rate Mode (Figure 37) Data Setup Time - 16 Bit Resolution Mode (Figure 39) tLAT_INTERP tDATASETUP_synch tDATASETUP_double tDATASETUP_16 64 / fOSC 48 / fOSC 48 / fOSC 48 / fOSC 65 / fOSC 56 / fOSC 60 / fOSC 60 / fOSC s s s s (7) (7) (7) (7) 141 142 143 144 145 Programming Mode Timing Programming Mode Sync Pulse Period Programming Mode Command Timeout OTP Write Command to VCC = VPP OTP Write CMD Response to OTP programming start Time to program the OTP User Array tS-S_PM_L tPM_TIMEOUT tPROG_HOLD tPROG_DELAY tPROG_ARRAY 495 70 500 4 * tS-S_PM 505 20 40 s s s ms ms (7) (7) (7) (7) (7) * * MMA51xxLW Sensors Freescale Semiconductor, Inc. 9 2.7 Dynamic Electrical Characteristics - Signal Chain VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified # Characteristic Symbol Min Typ Max Units 146 Internal Oscillator Frequency * fOSC 3.80 4 4.20 MHz (1) 147 148 149 150 DSP Low-Pass Filter (Note15) Cutoff frequency LPF0 (referenced to 0 Hz) Filter Order LPF0 Cutoff frequency LPF1 (referenced to 0 Hz) Filter Order LPF1 * * * * fC_LPF0 OLPF0 fC_LPF1 OLPF1 400 3 400 4 Hz 1 Hz 1 (7) (7) (7) (7) 151 152 153 154 155 156 157 158 159 160 161 162 163 164 DSP Offset Cancellation Low-Pass Filter (Note15) Offset Cancellation Low-Pass Filter Input Sample Rate Stage 1 Cutoff frequency, Startup Phase 1 Stage 1 Filter Order, Startup Phase 1 Stage 2 Cutoff frequency, Startup Phase 1 Stage 2 Filter Order, Startup Phase 1 Cutoff frequency, Option 0 Filter Order, Option 0 Offset Cancellation Output Update Rate (8-Bit Mode) Offset Cancellation Output Step Size (8-Bit Mode) Offset Cancellation Output Update Rate (10-Bit Mode) Offset Cancellation Output Step Size (10-Bit Mode) Offset Monitor Update Frequency Offset Monitor Count Limit Offset Monitor Counter Size tOC_SampleRate fC_OC10 OOC10 fC_OC03 OOC03 fC_OC0 OOC0 tOffRate_8 OFFStep_8 tOffRate_10 OFFStep_10 OFFMONOSC OFFMONCNTLIMIT OFFMONCNTSIZE 256 10.0 1 0.300 1 0.100 1 fOSC / 2e6 0.125 fOSC / 2e6 0.5 fOSC / 2000 4096 8192 s Hz 1 Hz 1 Hz 1 s LSB s LSB Hz 1 1 (7) (7) (7) (7) (7) (7) (7) (7) (7) (7) (7) (7) (7) (7) 165 166 167 168 Sensing Element Natural Frequency 60g 120g 240g 480g fgcell_Z60 fgcell_Z120 fgcell_Z240 fgcell_Z480 7000 7000 13600 16289 8000 8000 15100 17996 Hz Hz Hz Hz (9) (9) (9) (9) 169 170 171 172 Sensing Element Roll-off Frequency (-3 db) 60g 120g 240g 480g fgcell_Z60 fgcell_Z120 fgcell_Z240 fgcell_Z480 798 798 2000 2250 2211 2211 4700 6350 Hz Hz Hz Hz (9) (9) (9) (9) 173 174 175 176 Sensing Element Damping Ratio 60g 120g 240g 480g gcell_Z60 gcell_Z120 gcell_Z240 gcell_Z480 1.870 1.870 1.750 1.250 4.610 4.610 3.500 3.000 (9) (9) (9) (9) 177 178 179 180 Sensing Element Delay (@100 Hz) 60g 120g 240g 480g fgcell_delay_Z60 fgcell_delay_Z120 fgcell_delay_Z240 fgcell_delay_Z480 77 77 40 21 200 200 86 60 s s s s (9) (9) (9) (9) 181 Package Resonance Frequency fPackage 100 kHz (9) MMA51xxLW 10 Sensors Freescale Semiconductor, Inc. 2.8 Dynamic Electrical Characteristics - Supply and SPI VL (VCC - VSS) VH, TL TA TH, T 25 K/min, unless otherwise specified # Characteristic Symbol Min Typ Max Units tSET 5 ms (3) tINT_INIT 16000 / fOSC s (7) tVCC_MICROCUTmin tVCC_MICROCUT tVCC_RESET 30 50 1000 s s s (3) (3) (3) 182 Quiescent Current Settling Time (Power Applied to Iq = IIDLE 2 mA) 183 Reset Recovery Internal Delay (After internal POR) 184 185 186 VCC Micro-cut (CBUF=CREG=CREGA=1 F) Survival Time (VCC disconnect without Reset, CBUF=CREG=CREGA=700 nF) Survival Time (VCC disconnect without Reset, CBUF=CREG=CREGA=1 F) Reset Time (VCC disconnect above which Reset is guaranteed) 187 188 189 190 VBUF, Capacitor Monitor Disconnect Time (Figure 10) POR to first Capacitor Test Disconnect Disconnect Time (Figure 10) Disconnect Delay, Asynchronous Mode (Figure 10) Disconnect Delay, Synchronous Mode (Figure 11) tPOR_CAPTEST tCAPTEST_TIME tCAPTEST_ADLY tCAPTEST_SDLY 12000 / fOSC 1.5 688 / fOSC 72 / fOSC 5.0 s s s s (7) (7) (7) (7) 191 192 193 VREG, VREGA Capacitor Monitor POR to first Capacitor Test Disconnect Disconnect Time Disconnect Rate tPOR_CAPTEST tCAPTEST_TIME tCAPTEST_RATE 12000 / fOSC 6 / fOSC 256 / fOSC s s s (7) (7) (7) 194 195 196 197 198 199 200 201 202 203 204 205 206 207 Serial Interface Timing (See Figure 7, CDOUT 80 pF, RDOUT 10 k) Clock (SCLK) period (10% of VCC to 10% of VCC) Clock (SCLK) high time (90% of VCC to 90% of VCC) Clock (SCLK) low time (10% of VCC to 10% of VCC) Clock (SCLK) rise time (10% of VCC to 90% of VCC) Clock (SCLK) fall time (90% of VCC to 10% of VCC) CS asserted to SCLK high (CS = 10% of VCC to SCLK = 10% of VCC) CS asserted to DOUT valid (CS = 10% of VCC to DOUT = 10/90% of VCC) Data setup time (DIN = 10/90% of VCC to SCLK = 10% of VCC) DIN Data hold time (SCLK = 90% of VCC to DIN = 10/90% of VCC) DOUT Data hold time (SCLK = 90% of VCC to DOUT = 10/90% of VCC) SCLK low to data valid (SCLK = 10% of VCC to DOUT = 10/90% of VCC) SCLK low to CS high (SCLK = 10% of VCC to CS = 90% of VCC) CS high to DOUT disable (CS = 90% of VCC to DOUT = Hi Z) CS high to CS low (CS = 90% of VCC to CS = 90% of VCC) tSCLK tSCLKH tSCLKL tSCLKR tSCLKF tLEAD 320 120 120 60 20 10 0 60 1000 15 15 40 28 60 50 60 ns ns ns ns ns ns ns ns ns ns ns ns ns ns (9) (9) (9) (9) (9) (9) (9) (9) (9) (9) (9) (9) (9) (9) tACCESS tSETUP tHOLD_IN tHOLD_OUT tVALID tLAG tDISABLE tCSN 1. Parameters tested 100% at final test. 2. Parameters tested 100% at wafer probe. 3. Verified by characterization. 4. * Indicates critical characteristic. 5. Verified by qualification testing. 6. Parameters verified by pass/fail testing in production. 7. Functionality guaranteed by modeling, simulation and/or design verification. Circuit integrity assured through IDDQ and scan testing. Timing is determined by internal system clock frequency. 8. N/A. 9. Verified by simulation. 10. N/A. 11. Measured at VCC pin; VSYNC guaranteed across full VIDLE range. 12. Self-Test repeats on failure up to a ST_RPTMAX times before transmitting Sensor Error Message. 13. N/A. 14. Thermal resistance between the die junction and the exposed pad; cold plate is attached to the exposed pad. 15. Filter cutoff frequencies are directly dependent upon the internal oscillator frequency. MMA51xxLW Sensors Freescale Semiconductor, Inc. 11 tRS tS-S VSYNC tSYNC VIDLE VSYNC VCC GND Figure 5. Sync Pulse Characteristics VCC_UV_f + VCC_HYST VCC_UV_f Response Terminated if in process VCC VBUF_UV_f + VBUF_HYST VBUF_UV_f VBUF VREG_UV_f + VREG_HYST VREG_UV_f VREG VREGA_UV_f+VREGA_HYST VREGA_UV_f VREG POR Time Figure 6. Powerup Timing CS tLEAD tSCLKR tSCLK tSCLKF tCSN tSCLKH SCLK tSCLKL tLAG tACCESS tVALID tHOLD_OUT tDISABLE DOUT tHOLD_IN tSETUP DIN Figure 7. Serial Interface Timing MMA51xxLW 12 Sensors Freescale Semiconductor, Inc. 3 Functional Description 3.1 User Accessible Data Array A user accessible data array allows for each device to be customized. The array consists of an OTP factory programmable block, an OTP user programmable block, and read only registers for device status. The OTP blocks incorporate independent error detection circuitry for fault detection (reference Section 3.2). Portions of the factory programmable array are reserved for factory-programmed trim values. The user accessible data is shown in Table 3. Table 3. User Accessible Data Byte Addr (XLong Msg) Register $00 SN0 Nibble Addr (Long Msg) Bit Function Bit Function Nibble Addr (Long Msg) 7 6 5 4 $01 SN[7] SN[6] SN[5] SN[4] $00 Type 3 2 1 0 SN[3] SN[2] SN[1] SN[0] $01 SN1 $03 SN[15] SN[14] SN[13] SN[12] $02 SN[11] SN[10] SN[9] SN[8] $02 SN2 $05 SN[23] SN[22] SN[21] SN[20] $04 SN[19] SN[18] SN[17] SN[16] $03 SN3 $07 SN[31] SN[30] SN[29] SN[28] $06 SN[27] SN[26] SN[25] SN[24] $04 DEVCFG1 $09 0 0 1 0 $08 AXIS RNG[2] RNG[1] RNG[0] LOCK_U PCM SYNC_PD LATENCY $0A DATASIZE BLANKTIME P_CRC BAUD LPF[1] LPF[0] $0C TIMESLOTB[9] TIMESLOTB[8] TIMESLOTA[9] TIMESLOTA[8] $05 DEVCFG2 $0B $06 DEVCFG3 $0D TRANS_MD[1] TRANS_MD[0] $07 DEVCFG4 $0F TIMESLOTA[7] TIMESLOTA[6] TIMESLOTA[5] TIMESLOTA[4] $0E TIMESLOTA[3] TIMESLOTA[2] TIMESLOTA[1] TIMESLOTA[0] $08 DEVCFG5 $11 TIMESLOTB[7] TIMESLOTB[6] TIMESLOTB[5] TIMESLOTB[4] $10 TIMESLOTB[3] TIMESLOTB[2] TIMESLOTB[1] TIMESLOTB[0] F, R U, R $09 DEVCFG6 $13 INIT2_EXT ASYNC U_DIR[1] U_DIR[0] $12 U_REV[3] U_REV[2] U_REV[1] U_REV[0] $0A DEVCFG7 $15 MONTH[3] MONTH[2] MONTH[1] MONTH[0] $14 YEAR[3] YEAR[2] YEAR[1] YEAR[0] $0B DEVCFG8 $17 UD[2] UD[1] UD[0] DAY[4] $16 DAY[3] DAY[2] DAY[1] DAY[0] $0C SC $19 0 TM_B RESERVED IDEN_B $18 OC_INIT_B IDEF_B OFF_B 1 R $0D MFG_ID $1B MFG_ID[7] MFG_ID[6] MFG_ID[5] MFG_ID[4] $1A MFG_ID[3] MFG_ID[2] MFG_ID[1] MFG_ID[0] U, R Type codes F: Freescale programmed OTP location U: User programmable OTP location via PSI5 R: Readable register via PSI5 3.1.1 Device Serial Number Registers A unique serial number is programmed into the serial number registers of each device during manufacturing. The serial number is composed of the following information: Bit Range Content SN[12:0] Serial Number SN[31:13] Lot Number Serial numbers begin at 1 for all produced devices in each lot and are sequentially assigned. Lot numbers begin at 1 and are sequentially assigned. No lot will contain more devices than can be uniquely identified by the 13-bit serial number. Depending on lot size and quantities, all possible lot numbers and serial numbers may not be assigned. The serial number registers are included in the factory programmed OTP CRC verification. Reference Section 3.2.1 for details regarding the CRC verification. Beyond this, the contents of the serial number registers have no impact on device operation or performance, and are only used for traceability purposes. MMA51xxLW Sensors Freescale Semiconductor, Inc. 13 3.1.2 Factory Configuration Register (DEVCFG1) The factory configuration register is a factory programmed, read only register which contains user specific device configuration information. The factory configuration register is included in the factory programmed OTP CRC verification. Location Bit Address Register $04 DEVCFG1 7 Factory Default 3.1.2.1 6 5 4 3 2 1 0 0 0 1 0 AXIS RNG[2] RNG[1] RNG[0] 0 0 1 0 1 0 0 0 Axis Indication Bit (AXIS) The axis indication bit indicates the axes of sensitivity as shown below. This bit is factory programmed. 3.1.2.2 AXIS Sensitivity Axis 0 X 1 Z Range Indication Bits (RNG[2:0]) The range indication bits are factory programmed and indicate the full-scale range of the device as shown below. 3.1.3 RNG[2] RNG[1] RNG[0] Full-Scale Acceleration Range g-Cell Design PSI5 Init Data Transmission (D9) Reference Table 13 0 0 0 Reserved N/A 0001 0 0 1 60g Medium-g 0111 0 1 0 Reserved N/A 0010 0 1 1 120g Medium-g 1000 1 0 0 Reserved N/A 0011 1 0 1 240g High-g 1001 1 1 0 Reserved N/A 0100 1 1 1 480g High-g 1010 Device Configuration 2 Register (DEVCFG2) Device configuration register 2 is a user programmable OTP register that contains device configuration information. Location Bit Address Register 7 6 5 4 3 2 1 0 $05 DEVCFG2 LOCK_U PCM SYNC_PD LATENCY DATASIZE BLANKTIME P_CRC BAUD 0 0 0 0 0 0 0 0 Factory Default 3.1.3.1 User Configuration Lock Bit (LOCK_U) The LOCK_U bit allows the user to prevent writes to the user configuration array once programming is completed. If the LOCK_U bit is written to `1' when a PSI5 "Execute Programming of NVM" command is executed, the LOCK_U OTP bit will be programmed. Upon completion of the OTP programming, an OTP readout will be executed, locking the array from future OTP writes. The User Programmable OTP Array Error Detection is also activated (Reference Section 3.2.2). 3.1.3.2 PCM Enable Bit (PCM) The PCM bit enables the PCM output pin. When the PCM bit is set, the PCM output pin is active and outputs a Pulse Code Modulated signal proportional to the acceleration response. Reference Section 3.5.3.7 for more information regarding the PCM output. When the PCM bit is cleared, the PCM output pin is actively pulled low. MMA51xxLW 14 Sensors Freescale Semiconductor, Inc. 3.1.3.3 PCM PCM Output 0 Actively Pulled Low 1 PCM Signal Enabled Sync Pulse Pulldown Enable Bit (SYNC_PD) The sync pulse pulldown enable bit selects if the sync pulse pulldown is enabled once a sync pulse is detected. Reference Section 4.2.1.2 for more information regarding the sync pulse pulldown. SYNC_PD Sync Pulse Pulldown 0 Disabled 1 Enabled If Daisy Chain Mode is enabled, the Sync Pulse Pulldown is enabled as listed below: SYNC_PD Daisy Chain Address Programmed "Run Mode" Command Received Daisy Chain Address = `001' Sync Pulse Pulldown 0 x x x Disabled 1 No x x Enabled 1 Yes No x Disabled 1 Yes Yes No Disabled 1 Yes Yes Yes Enabled 3.1.3.4 Latency Selection Bit (LATENCY) The latency selection bit selects between one of two data latency methods to accommodate synchronized sampling or simultaneous sampling. Reference Section 4.5 for more information regarding latency and data synchronization. 3.1.3.5 Latency Data Latency 0 Simultaneous Sampling Mode (Latency relative to Sync Pulse) 1 Synchronous Sampling Mode (Latency relative to Time Slot) Data Size Selection Bit (DATASIZE) The data size selection bit selects one of two data lengths for the PSI5 response message as shown below. 3.1.3.6 DATASIZE Data Length 0 10 Bits 1 8 Bits PSI5 Sync Pulse Blanking Time Selection Bit (BLANKTIME) The PSI5 sync pulse blanking time selection bit selects the timing for ignoring sync pulses after successful reception of a sync pulse. Reference Section 4.2.1.1 for details regarding sync pulse detection and blanking. BLANKTIME Blanking Time Method 0 Maximum of tSYNC_OFF_500 or Response Transmission Complete 1 Blanking Time determined by end of response transmission for programmed time slot MMA51xxLW Sensors Freescale Semiconductor, Inc. 15 3.1.3.7 PSI5 Response Message Error Detection Selection Bit (P_CRC) The PSI5 response message error detection selection bit selects either even parity, or a 3-Bit CRC for error detection of the PSI5 response message. Reference Section 4.3.3 for details regarding response message error detection. P_CRC Parity or CRC 0 Parity 1 CRC Note: The PSI5 specification recommends parity for data lengths of 10 bits or less. 3.1.3.8 Baud Rate Selection Bit (BAUD) The baud rate selection bit selects one of two PSI5 baud rates as shown below. Reference Section 2.6 for baud rate timing specifications. 3.1.4 BAUD Baud Rate 0 Low Baud Rate (125 kBaud) 1 High Baud Rate (190.5 kBaud) Device Configuration Registers (DEVCFG3, DEVCFG4, DEVCFG5) Device configuration registers 3, 4, and 5 are user programmable OTP registers which contain device configuration information. Location Bit Address Register 7 6 5 4 $06 DEVCFG3 TRANS_MD[1] TRANS_MD[0] LPF[1] LPF[0] $07 DEVCFG4 TIMESLOTA[7] TIMESLOTA[6] TIMESLOTA[5] TIMESLOTA[4] TIMESLOTA[3] TIMESLOTA[2] TIMESLOTA[1] TIMESLOTA[0] $08 DEVCFG5 TIMESLOTB[7] TIMESLOTB[6] TIMESLOTB[5] TIMESLOTB[4] TIMESLOTB[3] TIMESLOTB[2] TIMESLOTB[1] TIMESLOTB[0] Factory Default 3.1.4.1 0 0 0 3 2 1 0 TIMESLOTB[9] TIMESLOTB[8] TIMESLOTA[9] TIMESLOTA[8] 0 0 0 0 0 PSI5 Transmission Mode Selection Bits (TRANS_MD[1:0]) The PSI5 transmission mode selection bits select the PSI5 transmission mode as shown below. TRANS_MD[1] TRANS_MD[0] Operating Mode Reference 0 0 Normal Mode (Asynchronous or Parallel, Synchronous) Section 4.5.1 0 1 Synchronous Double Sample Rate Mode Section 4.5.2 1 0 16-bit Resolution Mode (Two 10-bit Responses) Section 4.5.3 1 1 Daisy Chain Mode Section 4.5.4 3.1.4.2 Low-Pass Filter Selection Bit (LPF[1:0]) The low-pass filter selection bits select the low-pass filter for the acceleration signal as described below: LPF[1] LPF[0] Low-Pass Filter Selected 0 0 400 Hz, 3-Pole 0 1 400 Hz, 4-Pole 1 0 Reserved 1 1 Reserved MMA51xxLW 16 Sensors Freescale Semiconductor, Inc. 3.1.4.3 TimeSlot Selection Bits (TIMESLOTx[9:0]) The timeslot selection bits select the time slot(s) to be used for data transmission. Reference Section 4.5 for details regarding PSI5 transmission modes and time slots. Accepted time slot values are 0.5 s to 511.5 s in 0.5 s increments. Care must be taken to prevent from programming time slots which violate the PSI5 Version 1.3 specification, or time slots which will cause data contention. TIMESLOTx[9:0] ASYNC Bit Time Slot Reference 0 Default Time Slot (tTIMESLOT_DFLT) from start of Sync Pulse (tTRIG) Section 4.5 1 Asynchronous Mode Section 4.5.1.1 N/A TimeSlot Definition from start of Sync Pulse (tTRIG) in 0.5s Increments Section 4.5 00 0000 0000 Non-Zero Note: TIMESLOTB is only used for Synchronous Double Sample Rate Mode and 16-Bit Resolution Mode. 3.1.5 Device Configuration Registers 6, 7, and 8 (DEVCFG6, DEVCFG7, DEVCFG8) Device configuration registers 6, 7 and 8 are user programmable OTP registers which contain device configuration and user specific manufacturing information. The user specific manufacturing information bits have no impact on the performance, but are transmitted during the PSI5 initialization phase 2 in 10-bit mode. Location Bit Address Register 7 6 5 4 3 2 1 0 $09 DEVCFG6 INIT2_EXT ASYNC U_DIR[1] U_DIR[0] U_REV[3] U_REV[2] U_REV[1] U_REV[0] $0A DEVCFG7 MONTH[3] MONTH[2] MONTH[1] MONTH[0] YEAR[3] YEAR[2] YEAR[1] YEAR[0] $0B DEVCFG8 UD[2] UD[1] UD[0] DAY[4] DAY[3] DAY[2] DAY[1] DAY[0] 0 0 0 0 0 0 0 0 Factory Default 3.1.5.1 Initialization Phase 2 Data Extension Bit (INIT2_EXT) The initialization phase 2 data extension bit enables or disables data transmission in data fields D27 through D32 of PSI5 Initialization Phase 2 as shown below. 3.1.5.2 INIT2_EXT Description 0 D27 through D32 are set to "0000" 1 D27 through D32 are transmitted as defined in Section 4.4.2.1 Asynchronous Mode Bit (ASYNC) The asynchronous mode bit enables asynchronous data transmission as described in Section 3.1.4.3. 3.1.5.3 User Sensing Direction (U_DIR[1:0]) The user sensing direction registers are user programmable OTP registers which contain the module level sensing direction. This data is transmitted to the main ECU during PSI5 initialization phase 2 in 10-bit mode, as described in Section 4.4.2.1. 3.1.5.4 U_DIR[1] U_DIR[0] Module Sensing Direction As Defined in AKLV27 PSI5 Init Data Transmission (D8) Reference Table 13 0 0 Connector Direction () 0000 0 1 Bushing Direction () 0100 1 0 Perpendicular to and () 1000 1 1 Not used 1100 User Product Revision (U_REV[3:0]) The user product revision registers are user programmable OTP registers which contain the module production revision. The device supports up to 16 product revisions. This data is transmitted to the main ECU during PSI5 initialization phase 2 in 10-bit mode, as described in Section 4.4.2.1. MMA51xxLW Sensors Freescale Semiconductor, Inc. 17 3.1.5.5 User Production Date Information (YEAR[3:0], MONTH[3:0], DAY[4:0) The user production date information registers are user programmable OTP registers which contain the module production date. The table below shows the relationship between the stored values and the production date. Programmed Value Decoded Value Julian Date Value YEAR[3:0] Year JY[6:0] 0000 2009 0001001 * * * * * * * * * 1111 2024 0011000 MONTH[3:0] Month JM[3:0] 0000 N/A 0000 0001 January 0001 * * * * * * * * * 1100 December 1100 * * * * * * * * * 1111 N/A N/A DAY[4:0] Day JD[4:0] 00000 N/A 00000 00001 Day 1 00001 * * * * * * * * * 11111 Day 31 11111 The Julian date value is transmitted to the main ECU during PSI5 initialization phase 2 in 10-bit mode, as described in Section 4.4.2.1. 3.1.5.6 User Specific Data (UD[2:0]) The user specific data bits are user programmable OTP bits. These bits have no impact on device operation or performance. MMA51xxLW 18 Sensors Freescale Semiconductor, Inc. 3.1.6 Status Check Register (SC) The status check register is a read-only register containing device status information. Location Bit Address Register 7 6 5 4 3 2 1 0 $0C SC 0 TM_B RESERVED IDEN_B OC_INIT_B IDEF_B OFF_B 1 3.1.6.1 Test Mode Flag (TM_B) The test mode bit is cleared if the device is in test mode. TM_B 3.1.6.2 Operating Mode 0 Test Mode is active 1 Test Mode is not active Internal Data Error Flag (IDEN_B) The internal data error bit is cleared if a register data error detection mismatch is detected in the user accessible OTP array. A device reset is required to clear the error. 3.1.6.3 IDEN_B Error Condition 0 Error detection mismatch in user programmable OTP array 1 No error detected Offset Cancellation Init Status Flag (OC_INIT_B) The offset cancellation initialization status bit is set once the offset cancellation initialization process is complete, and the filter has switched to normal mode. 3.1.6.4 OC_INIT_B Error Condition 0 Offset Cancellation in initialization 1 Offset Cancellation initialization complete (tOC1 and tOC2 expired) Internal Factory Data Error Flag (IDEF_B) The internal factory data error bit is cleared if a register data CRC fault is detected in the factory programmable OTP array. A device reset is required to clear the error. 3.1.6.5 IDEF_B Error Condition 0 CRC error in factory programmable OTP array 1 No error detected Offset Error Flag (OFF_B) The offset error flag is cleared if the acceleration signal reaches the offset limit. OFF_B Error Condition 0 Offset error detected 1 No error detected MMA51xxLW Sensors Freescale Semiconductor, Inc. 19 3.1.7 Manufacturer ID (MFG_ID) The manufacturer ID register is a user programmable OTP register that contains the PSI5 manufacturer ID. The manufacturer ID register has no impact on the performance, but is transmitted during the PSI5 initialization phase 2 in 10-bit mode. Location Bit Address Register 7 6 5 4 3 2 1 0 $0D MFG_ID MFG_ID[7] MFG_ID[6] MFG_ID[5] MFG_ID[5] MFG_ID[3] MFG_ID[2] MFG_ID[1] MFG_ID[0] 0 0 0 0 0 0 0 0 Factory Default 3.2 OTP Array CRC Verification 3.2.1 Factory Programmed OTP Array CRC Verification The Factory programmed OTP array is verified for errors with a 3-bit CRC. The CRC verification is enabled only when the factory programmed array is locked. The CRC verification uses a generator polynomial of g(x) = X3 + X + 1, with a seed value = `111'. Once the CRC verification is enabled, the CRC is continuously calculated on all bits in registers $00, $01, $02, $03, and $04 and on the factory programmable device configuration bits with the exception of the factory lock bit. Bits are fed in from right to left (LSB first), and top to bottom (lower addresses first) in the register map. The calculated CRC is then compared against the stored 3 bit CRC. If a CRC error is detected in the OTP array, the IDEF_B bit is cleared in the SC register. The CRC verification is completed on the memory registers which hold a copy of the fuse array values, not the fuse array values. 3.2.2 User Programmable OTP Array Error Detection The user programmable OTP array is independently verified for errors. The Error Detection is enabled only when the LOCK_U bit in the user data register array is set. When a PSI5 Programming Mode "Execute Programming of NVM" command is received and the LOCK_U bit is set, the device calculates the error detection code and writes the code to NVM, enabling the Error Detection. Once the error detection is enabled, the error detection code is continuously calculated on all bits in registers $05, $06, $07, $08, $09, $0A, $0B and $0D with the exception of the LOCK_U bit. The calculated code is then compared against the stored error code. If a mismatch is detected, the IDEN_B bit is cleared in the SC register. The error detection is completed on the memory registers which hold a copy of the fuse array values, not the fuse array values. MMA51xxLW 20 Sensors Freescale Semiconductor, Inc. 3.3 Voltage Regulators The device derives its internal supply voltage from the VCC and VSS pins. Separate internal voltage regulators are used for the analog (VREGA) and digital circuitry (VREG). The analog and digital regulators are supplied by a buffer regulator (VBUF) to provide immunity from EMC and supply dropouts on VCC. External filter capacitors are required, as shown in Figure 1. The voltage regulator module includes voltage monitoring circuitry which holds the device in reset following power-on until the internal voltages have increased above the under-voltage detection thresholds. The voltage monitor asserts internal reset when the external supply or internally regulated voltages fall below the under-voltage detection thresholds. A reference generator provides a reference voltage for the converter. VCC VREF VBUF VOLTAGE REGULATOR VBUF VREGA = 2.50 V VOLTAGE REGULATOR BIAS GENERATOR VREGA TRIM BANDGAP REFERENCE VREF TRIM TRIM REFERENCE VREF_MOD = 1.250 V VREGA OSCILLATOR TRIM CONVERTER GENERATOR VBUF VREF OTP ARRAY VOLTAGE REGULATOR VREG = 2.50 V VREG DIGITAL LOGIC DSP VCC COMPARATOR Micro-cut VBUF COMPARATOR POR VREG VREGA VREF COMPARATOR COMPARATOR Figure 8. Voltage Regulation and Monitoring MMA51xxLW Sensors Freescale Semiconductor, Inc. 21 3.3.1 VBUF, VREG, and VREGA Regulator Capacitor The internal regulators require an external capacitor between each of the regulator pins (VBUF, VREG, or VREGA) and the associated the VSS / VSSA pin for stability. Figure 1 shows the recommended types and values for each of these capacitors. 3.3.2 VCC, VBUF, VREG, and VREGA Under-Voltage Monitor A circuit is incorporated to monitor the supply voltage (VCC) and all internally regulated voltages (VBUF, VREG, and VREGA). If any of internal regulator voltages fall below the specified under-voltage thresholds in Section 2, the device will be reset. If VCC falls below the specified threshold, PSI5 transmissions are terminated for the present response. Once the supply returns above the threshold, the device will respond to the next detected sync pulse. Reference Figure 9. VCC micro-cut occurs VCC VBUF VCC under-voltage detected VREG VREGA Response Terminated IDATA POR Time Figure 9. VCC Micro-Cut Response MMA51xxLW 22 Sensors Freescale Semiconductor, Inc. 3.3.3 VBUF, VREG, and VREGA Capacitance Monitor A monitor circuit is incorporated to ensure predictable operation if the connection to the external VBUF, VREG, or VREGA, capacitor becomes open. In asynchronous mode, the VBUF regulator is disabled tCAPTEST_ADLY seconds after each data transmission for a duration of tCAPTEST_TIME seconds. If the external capacitor is not present, the regulator voltage will fall below the internal reset threshold, forcing a device reset. In synchronous mode, the VBUF regulator is disabled tCAPTEST_SDLY seconds after each sync pulse for a duration of tCAPTEST_TIME seconds. If the external capacitor is not present, the regulator voltage will fall below the internal reset threshold, forcing a device reset. The VREG and VREGA regulators are disabled at a continuous rate (tCAPTEST_RATE), for a duration of tCAPTEST_TIME seconds. If either external capacitor is not present, the associated regulator voltage will fall below the internal reset threshold, forcing a device reset. IDATA tCAPTEST_TIME tCAPTEST_ADLY Capacitor Present Capacitor Open CAP_Test VBUF VBUF_UV_f POR Time Figure 10. VBUF Capacitor Monitor - Asynchronous Mode VCC tCAPTEST_SDLY tCAPTEST_TIME tTRIG CAP_Test VBUF Capacitor Present Capacitor Open VBUF_UV_f POR Time Figure 11. VBUF Capacitor Monitor - Synchronous Mode MMA51xxLW Sensors Freescale Semiconductor, Inc. 23 tCAPTEST_RATE tCAPTEST_TIME CAP_Test VREG Capacitor Present Capacitor Open VPORVREG_f POR Time Figure 12. VREG Capacitor Monitor tCAPTEST_RATE tCAPTEST_TIME CAP_Test VREGA Capacitor Present Capacitor Open VPORREGA_f POR Time Figure 13. VREGA Capacitor Monitor 3.4 Internal Oscillator A factory trimmed oscillator is included as specified in Section 2. MMA51xxLW 24 Sensors Freescale Semiconductor, Inc. 3.5 Acceleration Signal Path 3.5.1 Transducer The transducer is an overdamped mass-spring-damper system defined by the following transfer function: where: 2 n H ( s ) = --------------------------------------------------------2 2 s + 2 n s + n = Damping Ratio n = Natural Frequency = 2 fn Reference Section 2.7 for transducer parameters. 3.5.2 Converter A sigma delta modulator converts the differential capacitance of the transducer to a 1 MHz data stream that is input to the DSP block. g-CELL 1= CTOP VX FIRST INTEGRATOR CINT1 z-1 SECOND INTEGRATOR 2 z-1 1 - z-1 CBOT 1-BIT QUANTIZER _OUT 1 - z-1 ADC C = CTOP - CBOT 1 2 DAC V = C x VX / CINT1 V = 2 x VREF Figure 14. Converter Block Diagram 3.5.3 Digital Signal Processing Block A Digital Signal Processing (DSP) block is used to perform signal filtering and compensation. A diagram illustrating the signal processing flow within the DSP block is shown in Figure 15. B A _OUT DOWNSAMPLING E D C LOW-PASS FILTER SINC FILTER COMPENSATION OFFSET OFFSET CANCELLATION CANCELLATION LOW-PASS FILTER OUTPUT RATE LIMITING F OUTPUT H G SCALING INTERPOLATION OUTPUT Figure 15. Signal Chain Diagram MMA51xxLW Sensors Freescale Semiconductor, Inc. 25 Table 4. Signal Chain Characteristics Description Sample Time (s) Data Width (Bits) SD 1 1 A Over Range (Bits Signal Width (Bits) Signal Noise (Bits) Signal Margin (Bits) Typical Block Latency 1 Reference Section 3.5.2 203/fosc B SINC Filter 16 20 13 C Low-Pass Filter 16 26 4 10 3 9 D Compensation 16 26 4 10 3 9 E Down Sampling 16 26 4 10 3 9 F High Pass Filter 16 26 4 10 3 9 Reference Section 3.5.3.2 Section 3.5.3.2 Section 3.5.3.2 68/fosc Reference Section 3.5.3.3 Section 3.5.3.3 DSP Sampling G 16 10 4/fosc Section 3.5.3.5 1 10 64/fosc Section 3.5.3.5 10-Bit Output Scaling H Interpolation 3.5.3.1 Decimation Sinc Filter The serial data stream produced by the converter is decimated and converted to parallel values by a 3rd order 16:1 sinc filter with a decimation factor of 16. 3 1 - z -16 H ( z ) = ------------------------------------16 x ( 1 - z - 1 ) Figure 16. Sinc Filter Response, tS = 16 s MMA51xxLW 26 Sensors Freescale Semiconductor, Inc. 3.5.3.2 Low-Pass Filter Data from the Sinc filter is processed by an infinite impulse response (IIR) low-pass filter. ( n 11 z 0 ) + ( n 12 z - 1 ) + ( n 13 z - 2 ) ( n 21 z 0 ) + ( n 22 z - 1 ) + ( n 23 z - 2 ) H ( z ) = a 0 ------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------( d 11 z 0 ) + ( d 12 z - 1 ) + ( d 13 z - 2 ) ( d 11 z 0 ) + ( d 22 z - 1 ) + ( d 23 z - 2 ) The device provides the option for one of two low-pass filters. The filter is selected with the LPF[1:0] bits in the DEVCFG3 register. The filter selection options are listed in Section 3.1.4.2. Response parameters for the low-pass filter are specified in Section 2.7. Filter characteristics are illustrated in Figure 17 and Figure 18. Table 5. Low-Pass Filter Coefficients Description Filter Coefficients Group Delay a0 5.189235225042199e-02 n11 1.629077582099646e-03 d11 1.0 n12 1.630351547919014e-03 d12 -9.481076477495780e-01 0 d13 0 n21 2.500977520825902e-01 d21 1.0 n22 4.999999235890745e-01 d22 -1.915847097557409e+00 n23 2.499023243303036e-01 d23 9.191065266874253e-01 a0 3.143225986084408e-03 n11 9.951105668343345e-04 d11 1.0 n12 2.003487780064749e-03 d12 -1.892328151433503e+00 400 Hz, 4-Pole LPF n13 1.008466113720278e-03 d13 8.954713774195870e-01 n21 2.516720624825626e-01 d21 1.0 n22 4.999888752940916e-01 d22 -1.918978239761011e+00 n23 2.483390622233452e-01 d23 9.229853042218408e-01 400 Hz, 3-Pole LPF n13 2816/fosc 3392/fosc Note: Low-Pass Filter values do not include g-cell frequency response. MMA51xxLW Sensors Freescale Semiconductor, Inc. 27 Figure 17. Low-Pass Filter Characteristics: fC = 400 Hz, 4-Pole, tS = 16 s MMA51xxLW 28 Sensors Freescale Semiconductor, Inc. Figure 18. Low-Pass Filter Characteristics: fC = 400 Hz, 3-Pole, tS = 16 s MMA51xxLW Sensors Freescale Semiconductor, Inc. 29 3.5.3.3 Offset Cancellation The device provides an optional offset cancellation circuit to remove internal offset error. A block diagram of the offset cancellation is shown in Figure 19. INPUT DATA INC/DEC OFFSET CANCELLATION LOW-PASS FILTER n + ( n z-1 ) 1 2 a ------------------------------------0 d + ( d z-1 ) 1 2 TO_OUTPUT SCALING OUT COUNTER 0.5 Hz (Derived from fOSC) Input Data downsampled to 256s CLK OFFMONNEG INC/DEC OUT OFF_ERR UP/DOWN COUNTER OFFMONPOS 2 kHz (Derived from fOSC) OFFMONCNTLIMIT CLK Figure 19. Offset Cancellation Block Diagram The transfer function for the offset LPF is: no 1 + ( no 2 z - 1 ) H ( z ) = ao 0 ---------------------------------------------do 1 + ( do 2 z - 1 ) Response parameters are specified in Section 2 and the offset LPF coefficients are specified in Table 7. During startup, two phases of the offset LPF are used to allow for fast convergence of the internal offset error during initialization. The timing and characteristics of each phase are shown in Table 6 and Table 7 and specified in Section 2. For more information regarding the startup timing, reference the PSI5 initialization information in Section 4.4. The offset low-pass filter used in normal operation is selected by the OC_FILT bit as shown in Table 6. During the Initialization Self-Test phase, the offset cancellation circuit output value is frozen. During normal operation, output rate limiting is applied to the output of the high pass filter. Rate limiting updates the offset cancellation output by OFFStep_xx LSB every tOffRate_xx seconds. Table 6. Offset Cancellation Startup Characteristics and Timing Offset Cancellation Startup Phase Offset LPF Output Rate Limiting Total Time for Phase 1 10 Hz Bypassed 80 ms 2 0.3 Hz Bypassed 70 ms Self-Test 0.3 Hz Bypassed (Frozen during ST2) 96 ms per Self-Test Sequence (up to 6 repeats) Complete 0.1 Hz Enabled N/A MMA51xxLW 30 Sensors Freescale Semiconductor, Inc. Table 7. High Pass Filter Coefficients Description 10 Hz HPF 0.3 Hz HPF 0.1 Hz HPF Coefficients Group Delay ao0 0.015956938266754 no1 0.499998132328277 do1 1.0 no2 0.499998132328277 do2 -0.984043061733246 ao0 0.000482380390167 no1 0.499938218213271 do1 1.0 no2 0.499938218213271 do2 -0.999517619609833 ao0 0.0001608133316040 no1 0.4999999403953552 do1 1.0 no2 0.4999999403953552 do2 -0.9998391270637512 16.384 ms 537.6 ms 1591ms Figure 20. 10 Hz Offset Cancellation Low-Pass Filter Characteristics Figure 21. 0.1 Hz Offset Cancellation Low-Pass Filter Characteristics MMA51xxLW Sensors Freescale Semiconductor, Inc. 31 3.5.3.4 Offset Monitor The device includes an offset monitor circuit. The output of the single pole low-pass filter in the offset cancellation block is continuously monitored against the offset limits specified in Section 2.4. An up/down counter is employed to count up If the output exceeds the limits, and to count down if the output is within the limits. The output of the counter is compared against the count limit OFFMONCNTLIMIT. If the counter exceeds the limit, the OFF_B flag in the SC register is cleared. The counter rails once the max counter value is reached (OFFMONCNTSIZE). The offset monitor is disabled during Initialization Phase 1, Phase 2, and Phase 3. 3.5.3.5 Data Interpolation The device includes 16 to 1 linear data interpolation to minimize the system sample jitter. Each result produced by the digital signal processing chain is delayed one sample time. On detection of a sync pulse the transmitted data is interpolated from the 2 previous samples, resulting in a latency of one sample time, and a maximum signal jitter of 1/16 of a sample time. Reference Section 4.5 for more information regarding interpolation and data latency. 3.5.3.6 Output Scaling The 26 bit digital output from the DSP is clipped and scaled to a 10-bit or 8-bit word which spans the acceleration range of the device. Figure 22 shows the method used to establish the output acceleration data word from the 26-bit DSP output. Over Range D25 D24 Signal D23 D22 Noise D21 D20 D19 D18 D17 D16 D15 D14 8-bit Data Word D21 D20 D19 D18 D17 D16 D15 D14 10-bit Data Word D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 Margin D9 D8 ... D2 D1 D0 Using Rounding D13 D12 Using Rounding Figure 22. 10-Bit Output Scaling Diagram 3.5.3.7 PCM Output Function The device provides the option for a PCM output function. The PCM output is activated if the PCM bit is set in the DEVCFG2 register. When the PCM function is enabled, a 4 MHz Pulse Code Modulated signal proportional to the upper 9 bits of the 10-bit acceleration response is output onto the PCM pin. The PCM output is intended for test use only. D[21:13] Output Scaling Section 3.5.3.6 A PCM CARRY 9 Sample updated every 16S 9 Bit ADDER 9 B SUM fCLK = 4 MHz 9 DD QQ DD QQ DD QQ DDFF QQ DFF Q FF FF FF FF FF FF FF CLK QQ CLK CLK QQ CLK CLK QQ CLK CLK QQ CLK CLK Q Figure 23. PCM Output Function Block Diagram MMA51xxLW 32 Sensors Freescale Semiconductor, Inc. 3.6 Overload Response 3.6.1 Overload Performance The device is designed to operate within a specified range. Acceleration beyond that range (overload) impacts the output of the sensor. Acceleration beyond the range of the device can generate a DC shift at the output of the device that is dependent upon the overload frequency and amplitude. The g-cell is overdamped, providing the optimal design for overload performance. However, the performance of the device during an overload condition is affected by many other parameters, including: * g-cell damping * Non-linearity * Clipping limits * Symmetry Figure 24 shows the g-cell, ADC and output clipping of The device over frequency. The relevant parameters are specified in Section 2. g-cellRolloff Acceleration (g) Region Clipped by Output LPFRolloff io R eg nC ed lipp by g l -cel Determined by g-cell roll-off and ADC clipping e to DC n du arity A o i t y r sto n-Line ed b l Di o lipp igna and N nC S o i f g o y r t n Re e o i Reg Asymm gg-cell_Clip gADC_Clip Determined by g-cell roll-off and full-scale range gRange_Norm Region of Interest fLPF Region of No Signal Distortion Beyond Specification fg-Cell 5kHz 10kHz Frequency (kHz) Figure 24. Output Clipping vs. Frequency 3.6.2 Sigma Delta Modulator Over Range Response Over Range conditions exist when the signal level is beyond the full-scale range of the device but within the computational limits of the DSP. The converter can saturate at levels above those specified in Section 2 (GADC_CLIP). The DSP operates predictably under all cases of over range, although the signal may include residual high frequency components for some time after returning to the normal range of operation due to non-linear effects of the sensor. MMA51xxLW Sensors Freescale Semiconductor, Inc. 33 4 PSI5 Layer and Protocol 4.1 Communication Interface Overview The communication interface between a master device and the MMA51xxLW is established via a PSI5 compatible 2-wire interface, with parallel or serial (daisy-chain) connections to the satellite modules. Figure 25 shows one possible system configuration for multiple satellite modules in parallel. MASTER DEVICE SATELLITE MODULE #1 MMA51xx VCC VSS Discrete Components VCC_OUT VSS_OUT VCC IData VSS SATELLITE MODULE #2 MMA51xx VCC VSS Discrete Components VCC_OUT VSS_OUT VCC IData VSS Figure 25. PSI5 Satellite Interface Diagram 4.2 Data Transmission Physical Layer The device uses a two wire interface for both its power supply (VCC), and data transmission. The PSI5 master supplies a preregulated voltage. Data transmissions and synchronization control from the PSI5 master to the device are accomplished via modulation of the supply voltage. Data transmissions from the device to the PSI5 master are accomplished via modulation of the current on the power supply line. 4.2.1 Synchronization Pulse The PSI5 master modulates the supply voltage in the positive direction to provide synchronization of the satellite sensor data. Upon reception of a synchronization pulse, the device delays a specified period of time, called a time slot, before transmitting acceleration data. For more details regarding time slots, refer to Section 3.1.4, and Section 4.5. SYNC PULSES VIDLE+ VSYNC VIDLE GND IIDLE + IMOD IIDLE Figure 26. Synchronous Communication Overview MMA51xxLW 34 Sensors Freescale Semiconductor, Inc. 4.2.1.1 Synchronization Pulse Detection The Synchronization (Sync) pulse detection block generates a valid synchronization pulse signal following the detection of an externally generated Sync pulse. This signal resets the Sync pulse time reference (tTRIG), and initiates the timers associated with response messages. The supply voltage can vary throughout the specified range, so the external Sync pulses may have different absolute voltage levels. Thus, the Sync pulse detection threshold (VCC_SYNC) is dependent not only on the Sync pulse absolute voltage, but also on the supply voltage. Figure 27 shows a block diagram of the Sync pulse detection circuit. VCC SYNC_OFF SYNC_OFFSET R VSYNC_REF VSYNC_COMP D CONTROL COUNTER SYNC_LPF LOGIC fOSC/2 SYNC_DET SYNC_LPF_RESET SYNC_LPF_RESET VSS Figure 27. Synchronization Pulse Detection Circuit The start of a Sync pulse is detected when the comparator output is set (VSYNC exceeds VSYNC_REF). The comparator output is input into a counter, and the counter is updated at a fixed frequency of fOSC/2. At a fixed time after the initial sync pulse detection (tSYNC_LPF_RST_ST), the counter is compared against a limit (the minimum value of tSYNC). If the counter is above the limit, a valid sync pulse is detected. If the Sync pulse is valid, the following occur: 1. The valid Sync pulse detection signal is set. 2. The detection counter is reset and disabled for tSYNC_OFF (referenced from tTRIG). tSYNC_OFF is a user programmable option. Reference Section 3.1.3.6 for details on the selectable option, and Section 2.6 for timing specifications for each option. a. If BLANKTIME = `0', tSYNC_OFF = tSYNC_OFF_500 b. If BLANKTIME = `1', tSYNC_OFF=tSYNC_OFF_VAR= tTIMESLOT_DLYx + (2+DATASIZE+(P_CRC?3:1)) *tBIT_x 3. The Sync pulse detection low-pass filter is reset for a specified time (tSYNC_LPF_RESET). If the Sync pulse is invalid, all timers are reset, and the detector becomes sensitive for the very next fSYNC_DET sample. The output of the comparator is monitored at the fOSC/2 frequency. Once the comparator output goes high, all of the internal timers are started, so that the tTRIG jitter is minimized. MMA51xxLW Sensors Freescale Semiconductor, Inc. 35 SYNC PULSE VSYNC_COMP SYNC_LPF_RESET SYNC OFF SYNC_PULSE_PD RESPONSE tA_SYNC_DLY tPD_DLY tPD_ON tSYNC_LPF_RST_ST tTRIG tSYNC_LPF_RST tSYNC_OFF_xxx tTIMESLOTx Figure 28. Synchronization Pulse Detection Timing 4.2.1.2 Synchronization Pulse Pulldown Function The device includes an optional Sync pulse pulldown function for systems in which the master device does not include an active pulldown function. The modulation current pulldown circuit is used, which sinks IMOD-IIDLE additional current from the IDATA pin. The pulldown current is activated after tPD_DLY (referenced to tTRIG), and is activated for tPD_ON. 4.3 Data Transmission Data Link Layer 4.3.1 Bit Encoding The device outputs data by modulation of the VCC current using Manchester 2 Encoding. Data is stored in a transition occurring in the middle of the bit time. The signal idles at the normal quiescent supply current. A logic low is defined as an increase in current at the middle of a bit time. A logic high is defined as a decrease in current at the middle of a bit time. There is always a transition in the middle of the bit time. If consecutive "1" or "0" data are transmitted, There will also be a transition at the start of a bit time. IMOD CURRENT IDLE CURRENT `0' BIT tBIT `1' BIT SENSED HIGH SENSED LOW CONSECUTIVE `0' DATA BITS CONSECUTIVE `1' DATA BITS Figure 29. Manchester 2 Data Bit Encoding MMA51xxLW 36 Sensors Freescale Semiconductor, Inc. 4.3.2 Data Transmission Transmission frames are composed of two start bits, an 8-Bit or 10-bit data word, and error detection bit(s). Data words are transmitted least-significant bit (LSB) first. A typical Manchester-encoded transmission frame is illustrated in Figure 30. Data Bit SB1 SB0 D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 PAR `0' `0' `1' `1' `1' `0' `0' `1' `1' `1' `1' `0' `1' SB1 IMOD Bit Value tBIT tTRAN = tBIT * (2+DATASIZE+(P_CRC?3:1)) tFRAME Figure 30. Example Manchester Encoded Data Transfer - PSI5-x10P 4.3.3 Error Detection Error detection of the transmitted data is accomplished via either a parity bit, or a 3-Bit CRC. The type of error detection used is selected by the P_CRC bit in the DEVCFG register. 4.3.3.1 Parity Error Detection When parity error detection is selected, even parity is employed. The number of logic `1' bits in the transmitted message must be an even number. 4.3.3.2 3-Bit CRC Error Detection When CRC error detection is selected, a 3-bit CRC is appended to each response message. The 3-bit CRC uses a generator polynomial of g(x) = X3+X+1, with a seed value = `111'. Data from the transmitted message is read into the CRC calculator LSB first, and the data is augmented with three `0's. Start bits are not used in the CRC calculation.Table 8 shows some example CRC calculation values for 10-bit data transmissions. Table 8. PSI5 3-Bit CRC Calculation Examples Data Transmitted CRC HEX D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 C2 C1 C0 0x000 0 0 0 0 0 0 0 0 0 0 1 1 0 0x0CC 0 0 1 1 0 0 1 1 0 0 0 1 1 0x151 0 1 0 1 0 1 0 0 0 1 0 0 0 0x1E0 0 1 1 1 1 0 0 0 0 0 0 1 1 0x1F4 0 1 1 1 1 1 0 1 0 0 0 1 0 0x220 1 0 0 0 1 0 0 0 0 0 1 0 0 0x275 1 0 0 1 1 1 0 1 0 1 1 1 1 0x333 1 1 0 0 1 1 0 0 1 1 0 0 1 0x3FF 1 1 1 1 1 1 1 1 1 1 1 0 0 MMA51xxLW Sensors Freescale Semiconductor, Inc. 37 4.3.4 Data Range Values Table 9 shows the details for each data range. Table 9. PSI5 Data Values 8-Bit Data Value Decimal 10-Bit Data Value Hex Decimal Hex +511 $1FF * * * +127 $7F * * * +502 $1F6 +126 $7E +501 $1F5 +125 $7D +500 $1F4 +499 $1F3 * * * * * * +489 $1E9 Description Reserved Sensor Defect Error Message N/A N/A +124 $7C +488 $1E8 Sensor Busy +123 $7B +487 $1E7 Sensor Ready +122 $7A Sensor Ready, but Unlocked +486 $1E6 +485 $1E5 N/A N/A * * * * * * +121 $79 +481 $1E1 +120 $78 +480 $1E0 * * * * * * * * * * * * +3 $03 +3 $03 +2 $02 +2 $02 +1 $01 +1 $01 0 0 0 0 -1 $FF -1 $3FF -2 $FE -2 $3FE -3 $FD -3 $3FD * * * * * * * * * * * * -120 $88 -480 $220 -121 $87 -481 $21F * * * * * * * * * * * * -124 $84 -496 $210 -125 $83 -497 $20F * * * * * * * * * * * * -128 $80 -512 $200 Reserved Reserved Maximum positive acceleration value Positive acceleration values 0g level Negative acceleration values Maximum negative acceleration value Initialization Data Codes 10-Bit Status Data Nibble 1 - 16 (0000 - 1111) (Dx) 8-Bit Status Data Nibble 1 - 4 (00 - 11) (Dx) Initialization Data IDs Block ID 1 - 16 (10-bit Mode) (IDx) Block ID 1 - 4 (8-Bit Mode) (IDx) MMA51xxLW 38 Sensors Freescale Semiconductor, Inc. 4.4 Initialization Following powerup, the device proceeds through an initialization process which is divided into 3 phases: * Initialization Phase 1: No Data transmissions occur * Initialization Phase 2: Sensor self-test and transmission of configuration information * Initialization Phase 3: Transmission of "Sensor Busy", and "Sensor Ready" / "Sensor Defect" message Once initialization is completed the device begins normal mode operation, which continues as long as the supply voltage remains within the specified limits. Normal Mode Sync Pulses Sync Pulses Ignored or Program Mode Entry VIDLE+ VSYNC ... VIDLE GND IIDLE + IMOD IIDLE POR INIT 1 NORMAL MODE INIT 3 INIT 2 Figure 31. PSI5 Sensor 10-Bit Initialization During PSI5 initialization, the device completes an internal initialization process consisting of the following: * Power-on Reset * Device Initialization * Program Mode Entry Verification * Offset Cancellation Initialization (2 Stages) * Self-Test Figure 32 shows the timing for internal and external initialization. POR Internal Delay tINT_INIT PSI5 Initialization Phase 1 PSI5 Initialization Phase 2 tPSI5_INIT1 tPSI5_INIT2 Self-Test Offset Cancellation Offset Cancellation Raw Offset Stage 1 Stage 2 Calculation tOC1 Sync Pulses Ignored tOC2 tST1 Programming Mode Entry 1) Min. 31 sync pulses 2) PME command Otherwise Sync Pulses Ignored tRS_PM tPME PSI5 PSI5 Initialization Normal Mode Phase 3 tPSI5_INIT3 Self-Test Self-Test Deflection Normal Data Verification Calculation tST2 tST3 Self-Test Repeat (If Necessary) ST_RPT * tST No PM Entry PM Entry No Transmissions In Response to Sync Pulses tPROG_MODE_START_DELAY Programming Mode Figure 32. Initialization Timing MMA51xxLW Sensors Freescale Semiconductor, Inc. 39 4.4.1 PSI5 Initialization Phase 1 During PSI5 initialization phase 1, the device begins internal initialization and self checks, but transmits no data. Initialization begins with the sequence below and shown in Figure 32: * Internal Delay to ensure analog circuitry has stabilized (tINT_INIT) * Offset Cancellation phase 1 Initialization (tOC1) * Monitor for the Programming Mode Entry Sequence (tPME) - A sequence of sync pulses received during the program mode entry window in PSI5 initialization phase 1 will allow the device to enter into a PSI5 programming mode if the LOCK_U bit is not set. Reference Section 5.2 for details. * Offset Cancellation phase 2 Initialization (tOC2) * If the Programming Mode Entry Sequence is not detected, the device enters Initialization Phase 2 (tPSI5_INIT2) 4.4.2 PSI5 Initialization Phase 2 During PSI5 initialization phase 2, the device continues it's internal self checks and transmits the PSI5 initialization phase 2 data. The PSI5 initialization data transmission format varies depending on whether the device is programmed for 8-bit or 10-bit data. Initialization is transmitted using the initialization data codes and IDs specified in Table 13, and in the order shown in Figure 33 and Figure 34. D1 ID11 D11 ID12 D12 D2 ... ID1k D1k ID21 D21 Repeat k times ID22 D22 ... ID2k D2k Repeat k times ... D32 ... ID321 D321 ID322 D322 ... ... ID32k D32k Repeat k times Figure 33. PSI5 Initialization Phase 2 Data Transmission Order (10-bit Mode) D1 ID1H 1 D1H1 ID1H 2 D1H2 D2 ... ID1H k Repeat k times D1Hk ID1L 1 D1L1 ID1L 2 D1L2 ... ... ID1L k Repeat k times D1Lk ... D9 ID9L 1 D9L1 ... ID9L 2 D9L2 ... ID9L k D9Lk Repeat k times Figure 34. PSI5 Initialization Phase 2 Data Transmission Order (8-bit Mode) The Initialization phase 2 time is calculated with the following equation: t PHASE2 = TRANS NIBBLE x k x ( DataFields ) x t S - S where: * TRANSNIBBLE * k * Data Fields * tS-S = # of Transmissions per Data Nibble 2 for 10-bit Data: 1 for ID, and 1 for Data 4 for 8-bit Data: 2 for ID, and 2 for Data = the repetition rate for the data fields = 32 data fields for 10-bit data, 9 data fields for 8-bit data = Sync Pulse Period MMA51xxLW 40 Sensors Freescale Semiconductor, Inc. 4.4.2.1 PSI5 Initialization Phase 2 (10-Bit Mode) In PSI5 initialization phase 2, 10-bit mode, the device transmits a sequence of sensor specific configuration and serial number information. The transmission data is in conformance with the PSI5 specification, Revision 1.3 and AKLV27, Revision 1.10. The data content and transmission format is shown in Table 10 and Table 11. Table 10 shows the 10-bit phase 2 timing for different operating modes. Times are calculated using the equation in Section 4.4.2. Table 10. Initialization Phase 2 Time (10-Bit Mode) Operating Mode Repetition Rate (k) # of Transmissions Nominal Phase 2 Time Asynchronous Mode (228 s) 8 512 116.7 ms Synchronous Mode (500 s) 4 256 128.0 ms Table 11. PSI5 Initialization Phase 2 Data (10-Bit Mode) PSI5 V1.2 PSI5 V1.2 Field ID # Nibble ID # Page Address PSI5 Nibble Address Register Address Description Value F1 D1 0000 Hard-coded Protocol Revision = V1.3 0100 F2 D2, D3 0001, 0010 Hard-coded Number of Data Blocks = 32 0010 0000 Manufacturer ID User F3 F4 D4 0011 MFG_ID[7:4] D5 0100 MFG_ID[3:0] D6, D7 0101, 0110 Hard-coded Sensor Type = Acceleration (high-g) 0000 0001 0111 U_DIR[1:0] = 00: 0000 U_DIR[1:0] = 01: 0100 U_DIR[1:0] = 10: 1000 U_DIR[1:0] = 11: 1100 (not used) Axis User D9 1000 60g: 0111 120g: 1000 240g: 1001 480g: 1010 Range Varies D10 1001 DEVCFG2[7:4] Sensor Specific Information User D11 1010 DEVCFG2[3:0] Sensor Specific Information User D12 1011 Hard-coded Product Revision Factory D13 1100 Hard-coded Product Revision Factory D14 1101 DEVCFG6[3:0] Product Revision User D15 1110 User D16 1111 D17 0000 D18 0001 DEVCFG7[7:0], DEVCFG8[4:0] converted to Binary coded Julian Date Reference Section 3.1.5.5 JY[6:3] D19 0010 SN0 (High Nibble) D20 0011 SN0 (Low Nibble) MMA51xx Serial Number Factory D21 0100 SN1 (High Nibble) MMA51xx Serial Number Factory D22 0101 SN1 (Low Nibble) MMA51xx Serial Number Factory D23 0110 SN2 (High Nibble) MMA51xx Serial Number Factory D24 0111 SN2 (Low Nibble) MMA51xx Serial Number Factory D25 1000 SN3 (High Nibble) MMA51xx Serial Number Factory 1001 SN3 (Low Nibble) MMA51xx Serial Number Factory 1010 Initial Raw Offset (Offset[3:0]) Raw Offset1 (If INIT2_EXT=1, `0000' otherwise) Varies 1011 Initial Raw Offset (Offset7:4]) Raw Offset1 (If INIT2_EXT=1, `0000' otherwise) Varies D8 F5 0 F6 F7 F8 D26 F9 D27 1 D28 JY[2:0], JM[3] User JM[2:0], JD[1] User JD[3:0] User MMA51xx Serial Number Factory 1 1. D29 1100 ([AvgSelfTest[1:0],Offset[9:8]]) Raw Off/Avg ST (If INIT2_EXT=1, `0000' otherwise) Varies D30 1101 Average Self-Test (AvgSelfTest[5:2]) Avg Self-Test1 (If INIT2_EXT=1, `0000' otherwise) Varies 1 D31 1110 Average Self-Test (AvgSelfTest[9:6]) Avg Self-Test (If INIT2_EXT=1, `0000' otherwise) Varies D32 1111 DEVCFG1 [7:4] Sensor Specific (If INIT2_EXT=1, `0000' otherwise) 0010 Offset and average self-test data will only be transmitted with sync pulse periods that guarantee the self-test phase1 and phase 2 will be complete prior to required transmission. If sync pulse periods faster than this are used, `0's will be transmitted instead of offset and/or average self-test data. MMA51xxLW Sensors Freescale Semiconductor, Inc. 41 4.4.2.2 Initialization Phase 2 (8-Bit Mode) In PSI5 initialization phase 2, 8-bit mode, the device transmits a sequence of sensor specific configuration and serial number information. The transmission data uses a format similar to the PSI5 specification, Revision 1.3 10-bit format modified for 8-bit transmission. The data content and transmission format is shown in Table 12 and Table 13. Table 12 shows the 8-bit phase 2 timing for different operating modes. Times are calculated using the equation in Section 4.4.2. Table 12. Initialization Phase 2 Time (8-Bit Mode) Operating Mode Repetition Rate (k) # of Transmissions Nominal Phase 2 Time Asynchronous Mode 0 (228 s) 16 576 131.3 ms Synchronous Mode (500 s) 8 288 144.0 ms Table 13. PSI5 Initialization Phase 2 Data (8-Bit Mode) PSI5 V1.2 PSI5 V1.2 Page Field ID # Nibble ID # Address PSI5 Half-Nibble Address Register Address Description Value F1 D1 H 0 00 Hard-coded Protocol Revision = V1.3 01 F1 D1 L 0 01 Hard-coded Protocol Revision = V1.3 00 F2 D2 H 0 10 Hard-coded Number of Data Blocks = 9 00 F2 D2 L 0 11 Hard-coded Number of Data Blocks = 9 10 F2 D3 H 1 00 Hard-coded Number of Data Blocks = 9 00 F2 D3 L 1 01 Hard-coded Number of Data Blocks = 9 00 F3 D4 H 1 10 Hard-coded, MFG_ID[7:6] Manufacturer ID F3 D4 L 1 11 Hard-coded, MFG_ID[5:4] Manufacturer ID F3 D5 H 2 00 Hard-coded, MFG_ID[3:2] Manufacturer ID F3 D5 L 2 01 Hard-coded, MFG_ID[1:0] Manufacturer ID F4 D6 H 2 10 Hard-coded Sensor Type = Acceleration (high-g) 00 F4 D6 L 2 11 Hard-coded Sensor Type = Acceleration (high-g) 00 F4 D7 H 3 00 Hard-coded Sensor Type = Acceleration (high-g) 00 F4 D7 L 3 01 Hard-coded Sensor Type = Acceleration (high-g) 01 F5 D8 H 3 10 F5 D8 L 3 11 U_DIR[1:0] = 00: 0000 U_DIR[1:0] = 01: 0100 U_DIR[1:0] = 10: 1000 U_DIR[1:0] = 11: 1100 (not used) F5 D9 H 4 00 F5 D9 L 4 01 User 60g: 0111 120g: 1000 240g: 1001 480g: 1010 User Axis User Varies Range Varies MMA51xxLW 42 Sensors Freescale Semiconductor, Inc. 4.4.3 Internal Self-Test During PSI5 Initialization Phase 2 and Phase 3, the device completes it's internal self-test as described below and shown in Figure 32. * Self-Test Phase 1 - Raw Offset Calculation - The average offset is calculated for tST1 (Self-Test Disabled). - If the INIT2_EXT bit is set, this 10-bit value is transmitted in Initialization Phase 2 (reference Section 4.4.2). * Self-Test Phase 2 - Self-Test Deflection Verification - - - - - - The offset cancellation value is frozen for tST2 + 2ms Self-Test is enabled After tST2/2, the acceleration output value is averaged for tST2/2 to determine the self-test value If the INIT2_EXT bit is set, this10-bit value is transmitted in Initialization Phase 2 (reference Section 4.4.2). The self-test value is compared against the limits specified in Section 2.5 Self-Test is disabled * Self-Test Phase 3 - Self-Test Normal Data Calculation - The average offset is calculated for tST3 - If Self-Test passed, the device advances to normal mode - If Self-Test failed, the device repeats Self-Test Phases 1 through 3 up to ST_RPT times. 4.4.4 Initialization Phase 3 During PSI5 initialization phase 3, the device completes it's internal self checks, and transmits a combination of "Sensor Busy", "Sensor Ready", or "Sensor Defect" messages as defined in Table 9. The number of messages transmitted in initialization phase 3 varies depending on the mode of operation, and the number of self-test repetitions. Self-Test is repeated on failure up to ST_RPT times to provide immunity to misuse inputs during initialization. Self-Test terminates successfully after one successful self-test sequence. Table 14 shows the nominal Initialization Phase 3 times for different operating modes and self-test repeats. Times are calculated using the following equation. ( t INTINIT + t OC1 + t OC2 + ( t ST1 + t ST2 + t ST3 ) x ( STRPT + 1 ) ) - ( t PSI5INIT1 + t PSI5INIT2xx ) t PSI5INIT3 = ROUNDUP --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- + 2 x t S - S tS - S Table 14. Initialization Phase 3 Time Operating Mode 8-Bit Asynchronous Mode 0 (228 s) 10-Bit Asynchronous Mode 0 (228 s) 8-Bit Synchronous Mode (500 s) 10-Bit Synchronous Mode (500 s) Self-Test Repetitions # of Sensor Busy Messages # of Sensor Ready or Sensor Defect Messages Nominal Phase 3 Time (ms) 0 0 0.46 1 359 82.31 2 780 178.30 3 1201 274.28 4 1622 370.27 5 2043 466.26 0 2 0.91 1 423 96.90 2 844 192.89 3 1265 288.88 4 1686 384.86 5 2107 0 0 1 138 70.00 2 480.85 1.00 2 330 166.00 3 522 262.00 4 714 358.00 5 906 454.00 0 0 1.00 1 170 86.00 2 362 182.00 3 554 278.00 4 746 374.00 5 938 470.00 MMA51xxLW Sensors Freescale Semiconductor, Inc. 43 4.5 PSI5 Transmission Modes 4.5.1 Normal Mode 4.5.1.1 Asynchronous Mode The device can be programmed to respond in asynchronous mode with the following settings: * TRANS_MD[1:0] = `00' ("Normal Mode") * ASYNC = `1' in the DEVCFG6 Register * TIMESLOTA[9:0] = 0x000 in the DEVCFG3 and DEVCFG4 registers In asynchronous mode, the device transmits data at a fixed rate (tASYNC) and will not respond to normal sync pulses. However, during initialization phase 1, sync pulses are monitored to decode the Programming Mode Entry Command and allow entry into Programming Mode if the LOCK_U bit is not set. 4.5.1.2 Simultaneous Sampling Mode The device can be programmed to respond in Simultaneous Sampling Mode by setting the TRANS_MD[1:0] bits to "Normal Mode", and by programming the LATENCY bit to "Simultaneous Sampling Mode". In Simultaneous Sampling Mode, the most recent interpolated acceleration data sample is latched at tTRIG (rising edge of Sync Pulse) and transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG. tLAT_INTERP tTIMESLOTA Figure 35. Simultaneous Sampling Mode MMA51xxLW 44 Sensors Freescale Semiconductor, Inc. 4.5.1.3 Synchronous Sampling Mode with Minimum Latency The device can be programmed to respond in Synchronous Sampling Mode with minimum latency by setting the TRANS_MD[1:0] bits to "Normal Mode", and by programming the LATENCY bit to "Synchronous Sampling Mode". In Synchronous Sampling Mode, the most recent interpolated acceleration data sample is latched at the time programmed in TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync Pulse). The data is transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG. tLAT_INTERP + tDATASETUP_synch tTIMESLOTA Figure 36. Synchronous Sampling Mode with Minimum Latency MMA51xxLW Sensors Freescale Semiconductor, Inc. 45 4.5.2 Synchronous Double Sample Rate Mode The device can be programmed to respond in Synchronous Double Sample Rate Mode with minimum latency by setting the TRANS_MD[1:0] bits to "Synchronous Double Sample Rate Mode". The LATENCY bit does not affect operation in this mode. In Synchronous Double Sample Rate Mode, the most recent interpolated acceleration data sample is latched at the time programmed in TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync Pulse). This data is transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG. In addition, the most recent interpolated acceleration data sample is latched at the time programmed in TIMESLOTB[9:0], relative to tTRIG (rising edge of Sync Pulse) This data is transmitted starting at the time programmed in TIMESLOTB[9:0], relative to tTRIG. When Synchronous Double Sample Rate Mode is enabled, PSI5 Initialization data is transmitted in both TIMESLOTA[9:0] and TIMESLOTB[9:0]. Identical data is transmitted in both Time slots, including the 10-bit resolution Raw Offset and Self-Test Data in Field 9, D27 though D31 if enabled. tLAT_INTERP+tDATASETUP_double tLAT_INTERP+tDATASETUP_double tTIMESLOTA tTIMESLOTB Figure 37. Synchronous Double Sample Rate Mode Note: In the event that the programmed values in TIMESLOTA[9:0] and TIMESLOTB[9:0] result in a conflict, no data will be transmitted in TIMESLOTB[9:0]. MMA51xxLW 46 Sensors Freescale Semiconductor, Inc. 4.5.3 16-Bit Resolution Mode The device can be programmed to respond in 16-bit Resolution Mode by setting the TRANS_MD[1:0] bits to "16-bit Resolution Mode". In this mode, the 26 bit digital output from the DSP is clipped and scaled to a 16-bit word. Figure 38 shows the method used to establish the 16-bit data word from the 26 bit DSP output. Over Range Signal Noise D25 D24 D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9 16-bit Data Word D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9 Margin D8 D7 D6 D8 D7 D6 D5 ... D2 D1 D0 Using Rounding Figure 38. 16-Bit Output Scaling Diagram 16-Bit Resolution Mode can be programmed to operate in either "Simultaneous Sampling Mode", or "Synchronous Sampling Mode", by setting the LATENCY bit to the desired operating mode. In Simultaneous Sampling Mode, the most recent interpolated acceleration data sample is latched at tTRIG (rising edge of Sync Pulse). In Synchronous Sampling Mode, the most recent interpolated acceleration data sample is latched at the time programmed in TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync Pulse). The most significant 10 bits (D[21:12]) are truncated and transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG. The 16-bit value is then clipped to 480 counts, and the least significant 10 bits (D15:D6) are transmitted starting at the time programmed in TIMESLOTB[9:0], relative to tTRIG. When 16-Bit Resolution Mode is enabled, PSI5 Initialization data is transmitted in both TIMESLOTA[9:0] and TIMESLOTB[9:0]. Identical data is transmitted in both Time slots, including the 10-Bit Resolution Raw Offset and Self-Test Data in Field 9, D27 though D31 if enabled. tTIMESLOTA tTIMESLOTB tLAT_INTERP + tDATASETUP_16 Figure 39. 16-Bit Resolution Mode with Synchronous Sampling Note: In the event that the programmed values in TIMESLOTA[9:0] and TIMESLOTB[9:0] result in a conflict, no data will be transmitted in TIMESLOTB[9:0]. MMA51xxLW Sensors Freescale Semiconductor, Inc. 47 4.5.4 Daisy Chain Mode The device can be programmed to operate in Daisy Chain Mode by setting the TRANS_MD[1:0] bits to "Daisy Chain Mode". Daisy Chain Mode can be programmed to operate in either "Simultaneous Sampling Mode", or "Synchronous Sampling Mode" by setting the LATENCY bit to the desired operating mode. In Simultaneous Sampling Mode, the most recent interpolated acceleration data sample is latched at tTRIG (rising edge of Sync Pulse). In Synchronous Sampling Mode, the most recent interpolated acceleration data sample is latched at the time slot for the daisy chain address programmed, relative to tTRIG (rising edge of Sync Pulse). When programmed to operate in Daisy Chain Mode, the procedure below is followed: * On powerup, the device proceeds through normal PSI5 initialization as specified in Section 4.4 using a predefined time slot tTIMESLOT_DCP. * Upon successful completion of Initialization Phase 3, including the 2 "Sensor Ready" or Sensor Defect" messages, responses to sync. pulses are terminated and the device waits for a PSI5 "Set Address" command defined in Table 15 and Table 16. - The Daisy Chain Programming command and response formats are defined in Section 5.4. - Valid Daisy Chain Addresses are defined in Table 17. - The response to the PSI5 Set Address command uses the predefined time slot tTIMESLOT_DCP. * After receiving a valid address and completing the response, sync. pulses are blanked for tDC_BLANKING. Once the blanking time expires, the device does not respond to any sync. pulses until a "Run Mode" command is received, as defined in Table 15 and Table 16. * When the "Run Mode" command is received, the device responds to this command using the programmed daisy chain time slot. All commands are then ignored, and sync pulses are responded to with acceleration data using the following response format, regardless of the state of the relevant bits in the Device Configuration Registers: Parameter Reference Value Time Slot Section 3.1.4.3 Default time slot specified in Table 17 Data Size Section 3.1.3.5 10-bit data Error Checking Section 3.1.3.7 Even Parity Baud Rate Section 3.1.3.8 Low Baud Rate: 125 kBaud * During initialization and Run Mode, the Sync pulse pulldown is enabled as specified in Section 3.1.3.3. Table 15. Daisy Chain Programming Commands and Responses SAdr FC # CMD Type A2 A1 A0 F2 F1 F0 D0 Short 0 0 0 A2 A1 A0 Set Sensor Address (Daisy Chain) D1 Short 1 1 1 0 0 0 Broadcast Message - "Run Mode" Command Response (OK) RC Response (Error) RD1 RC RD1 OK SAdr Error ErrN OK 0x000 Error ErrN Table 16. Daisy Chain Programming Response Code Definitions Response Code Definition Value RC = OK Command Message Received Properly 0x1E1 RC = Error Error during transmission of Command Message 0x1E2 SAdr Programmed Sensor Address, prepended with 0s Varies MMA51xxLW 48 Sensors Freescale Semiconductor, Inc. Table 17. Valid Daisy Chain Addresses Sensor Address (SAdr) Description Bus Switch Control Default Time Slot A2 A1 A0 0 0 0 Address of unprogrammed sensor N/A N/A 0 0 1 Sensor Address 1 CLOSED tTIMESLOT_DC1 0 1 0 Sensor Address 2 CLOSED tTIMESLOT_DC2 0 1 1 Sensor Address 3 CLOSED tTIMESLOT_DC3 1 0 0 Sensor Address 4 OPEN tTIMESLOT_DC1 1 0 1 Sensor Address 5 OPEN tTIMESLOT_DC2 1 1 0 Sensor Address 6 OPEN tTIMESLOT_DC3 1 1 1 Global Address for Broadcast Message to all Sensors N/A N/A 4.6 Error Handling 4.6.1 Sensor Defect Message The following failures will cause the device to transmit a "Sensor Defect" error message: 4.6.2 Error Condition Error Type Offset Error Temporary (Normal transmissions continue once offset returns within limits) Self-Test Failure Latched until reset IDEN_B, IDEF_B flag cleared Latched until reset No Response Error The following failures will cause the device to stop transmitting: Error Condition Error Type Under-Voltage Failure (VCC) Temporary: Normal transmissions continue once voltage returns above failure limit) MMA51xxLW Sensors Freescale Semiconductor, Inc. 49 5 Programming Mode Via PSI5 5.1 Introduction Programming mode via PSI5 is a synchronous communication mode that allows for bidirectional communication with the device. Programming mode is intended for factory programming of the OTP array. It is not intended for use in normal operation. 5.2 Programming Mode Via PSI5 Entry The device enters programming mode if and only if the following sequence occurs: * The device is unlocked (the LOCK_U bit in the DEVCFG2 register is `0'). * At least 31 sync pulses are detected, directly preceding the Programming Mode Entry Short Command during the Programming Mode Entry Window shown in Figure 32. - The window timing is defined in Section 2.6 (tPME). - The Sync pulses and Programming Mode Entry command must be received with a sync pulse period of tS-S_PM_L If the Programming Mode entry requirement is not met: * Programming Mode Entry is blocked until the device is Reset. * The device proceeds with PSI5 Initialization Phase 2, and PSI5 Initialization Phase 3. * The device enters normal mode, and responds as programmed to normal sync pulses. If the Programming Mode entry requirement is met: * Normal transmissions to sync pulses are terminated. * After a predefined Start Delay, the device begins to decode PSI5 Short and Long Commands. * The device responds only to valid PSI5 Short and Long Commands addressed to Sensor Address `001', as defined in Table 19. Note: The sync pulse pulldown is disabled in the Programming Mode Entry Window regardless of the state of the SYNCPD bit. MMA51xxLW 50 Sensors Freescale Semiconductor, Inc. 5.3 Programming Mode Via PSI5 - Data Link Layer 5.3.1 Programming Mode Via PSI5 - Command Bit Encoding Commands messages are transmitted via the modulation of the supply voltage. The presence of a sync pulse is a logic '1' and the absence of a sync pulse is a logic '0'. Sync pulses are expected at a rate of tS-S_PM_L. 5.3.2 Programming Mode Via PSI5 - Command Message Format Command message data frames consist of a start condition, 3 Start Bits (S[2:0]), a 3 bit Sensor Address (SAdr[2:0]), a 3-bit Function Code (FC[2:0]), an optional Register Address (RAdr[5:0]), an optional data field (D[3:0]), and a 3-bit CRC (C[2:0]. The start condition consists of one of the following: 1. A minimum of 5 consecutive logic `0's (with not sync bits) 2. A minimum of 31 consecutive logic `1's The command message format is shown in Figure 41. Start Bits Sensor Address Function Code Register Address Data CRC Response S2 S1 S0 SA0 SA1 SA2 FC0 FC1 FC2 RA0 RA1 RA2 RA3 RA4 RA5 D0 D1 D2 D3 C2 C1 C0 0 1 0 1 0 0 0 1 0 0 0 0 0 0 0 1 1 1 1 0 0 0 RC RD1 RD0 $3FF $3FF $3FF CRC Data to be written to register (optional) Register Address (optional) Function Codes for MMA51xx (Reference Section 5.3.6) Sensor Address - Fixed at 001 for MMA51xx Start Bit Sequence = 010 Figure 40. Programming Mode Via PSI5 Command Data Format Bit stuffing is necessary to maintain a synchronized time base between the command master and the device. A logic `1' Sync bit is added every 4th bit in the command message to ensure there will never be more than 3 logic '0' bits in a row. Sensor Address Start Bits Function Code Register Address Data CRC Response S2 S1 S0 Sy SA0 SA1 SA2 Sy FC0 FC1 FC2 Sy RA0 RA1 RA2 Sy RA3 RA4 RA5 Sy D0 D1 D2 Sy D3 C2 C1 Sy C0 0 1 0 1 1 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 1 1 1 1 1 0 0 1 0 RC RD1 RD0 $1E2 $3FF $3FF Figure 41. Programming Mode Via PSI5 Command Data Format with Sync Bits Once a command is received and verified, the device expects 2 to 3 consecutive sync pulses (depending upon the command message lengths described below). For each of these sync pulses, the device will respond with the following settings: Parameter Register Bits Reference Value Time Slot N/A N/A tTIMESLOT_DC1 Data Size DATASIZE = 0 Section 3.1.3.5 10-bit data Error Checking P_CRC = 0 Section 3.1.3.7 Even Parity Baud Rate BAUD Section 3.1.3.8 125 kBaud Sync Pulse Pulldown SYNCPD Section 3.1.3.3 Disabled Figure 42. Programming Mode Via PSI5 Response Message Settings MMA51xxLW Sensors Freescale Semiconductor, Inc. 51 5.3.2.1 Short Frame Command and Response Format Short frames are the simplest type of command message. No data is transmitted in a short frame command. Only specific instructions are performed in response to short frame commands. The Short Frame format is shown in Figure 43. Short Frame commands and responses are defined in Section 5.3.6, Table 19. Sensor Address Start Bits S2 S1 S0 Sy 0 1 0 1 Function Code SA0 SA1 SA2 Sy 1 0 0 CRC FC0 FC1 FC2 Sy 1 0 0 1 1 Response C2 C1 C0 RC RD1 0 0 0 $1E2 $3FF Figure 43. Programming Mode Via PSI5 Short Command and Response Format 5.3.2.2 Long Frame Command and Response Format Long frames allow for the transmission of data nibbles for register writes. The device can provide register data in response to a read or write request. The Long Frame format is shown in Figure 44. Long Frame commands and responses are defined in Section 5.3.6. Sensor Address Start Bits Function Code Register Address Data CRC Response S2 S1 S0 Sy SA0 SA1 SA2 Sy FC0 FC1 FC2 Sy RA0 RA1 RA2 Sy RA3 RA4 RA5 Sy D0 D1 D2 Sy D3 C2 C1 Sy C0 0 1 0 1 1 0 0 1 0 1 0 1 0 0 0 1 0 0 0 1 1 1 1 1 1 0 0 1 0 RC RD1 RD0 $1E2 $3FF $3FF Figure 44. Programming Mode Via PSI5 Long Command and Response Format 5.3.3 Command Message CRC Programming mode command error checking is accomplished by a 3-bit CRC. The 3-bit CRC is calculated using all message bits except start bits and sync bits. The CRC verification uses a generator polynomial of g(x) = X3+X+1, with a seed value = `111'. The data is provided to the CRC calculator in the order received (LSB first, SAdr, FC, RAdr, Data), and then augmented with three `0's. Table 9 shows some example CRC calculation values for 10-bit data transmissions. The calculated CRC is then compared against the received 3-bit CRC (received MSB first). If a CRC mismatch is detected, the device responds with a CRC Error response as defined in Section 5.3.7. 5.3.4 Command Sync Pulse Blanking Time In Programming Mode and Programming Mode Entry, the device employs a fixed Sync Pulse blanking time of tSYNC_OFF_500 regardless of the state of the BLANKTIME bit. 5.3.5 Command Timeout In the event that the device does not detect a sync pulse within a 4-bit window time (missing sync bit), the command reception will be terminated and the device will respond to the next sync pulse with a Short Frame Framing Error response as defined in Section 5.3.7. MMA51xxLW 52 Sensors Freescale Semiconductor, Inc. 5.3.6 Programming Mode Via PSI5 Command and Response Summary Table 18. Programming Mode Via PSI5 Commands and Responses CMD Type # SAdr FC Command Response (OK) Register Address Data Field RC OK Response (Error) RD1 RD0 RC 0x2AA N/A Error RD1 RD0 ErrN N/A S0 Short 100 Execute Programming of NVM N/A N/A S1 Short 101 Invalid Command N/A N/A No Response No Response S2 Short 110 Invalid Command N/A N/A No Response No Response S3 Short 111 Enter Programming Mode N/A N/A OK 0x0CA 001 N/A No Response LR Long 010 Read nibble located at address RA5:RA0 Varies Varies OK RData RData+1 Error ErrN 0x000 LW Long 011 Write nibble to register RA5:RA0 Varies Varies OK WData RA5:RA0 Error ErrN 0x000 XLR XLong 000 Invalid Command Any Any No Response No Response XLW XLong 001 Invalid Command Any Any No Response No Response Note: When reading the last address in the data array, RData+1 will always return 0x00. Table 19. Programming Mode Via PSI5 Response Code Definitions Response Code Definition Value RC = OK Command Message Received Properly 0x1E1 RC = Error Error during transmission of Command Message 0x1E2 RData Byte Contents of Register located at Byte address in which nibble address RA5:RA0 falls in. (Example: For RA5:RA0 = $04 - RData = Data at Byte Address $02) Varies RData + 1 Byte Contents of Register located at Byte address in which nibble address RA5:RA0 +2 falls in. (Example: For RA5:RA0 = $04 - RData + 1= Data at Byte Address $03) Varies WData Byte Contents of Register located at Byte address in which nibble address RA5:RA0 falls in after write operation. (Example: For RA5:RA0 = $04 - RData = Data at Byte Address $02) Varies 5.3.7 Programming Mode Via PSI5 Error Response Summary Table 20. Error Response Summary ErrN* Mnemonic Description Supported By MMA51xx 0000 General General Error No 0001 Framing Framing Error Yes 0010 CRC CRC Error on Received Message Yes 0011 Address Sensor Address Not Supported No (Invalid Address is ignored) 0100 FC Function Code Not Supported No (N/A) 0101 Data Range Unsupported Register Address Yes 0110 Write Protect Destination Address is Write protected (Locked) Yes 0111 Reserved Reserved No Reserved Reserved No 1000 1001 1010 1011 1100 1101 1110 1111 * ErrN is transmitted in the 4 LSBs of RD1. All other bits in the response data field are set to `0'. MMA51xxLW Sensors Freescale Semiconductor, Inc. 53 5.4 OTP Programming Via PSI5 Procedure 1. Enter Programming Mode. 2. Load desired data into the OTP shadow registers using PSI5 Long Write commands. 3. Send "Execute Programming of NVM"Short command. 4. Set VCC = VPP prior to, or within tPROG_HOLD after the "Execute Programming of NVM" Command has been transmitted. There is an internal delay of tPROG_DELAY after the "Execute Programming of NVM" Command is received until the OTP programming begins. 5. Delay a minimum of tPROG_USER. During the OTP Write sequence, sync pulses will be ignored. However, transmission of sync pulses during the OTP Write sequence should be prevented. 6. Read the SC register and verify IDEF_B flag is set (indicating the write is complete and successful, and the shadow registers have been refreshed with the OTP contents). 7. Read the OTP register values and compare to the desired values. MMA51xxLW 54 Sensors Freescale Semiconductor, Inc. 6 SPI Diagnostic and Programming Mode SPI Diagnostic and Programming Mode allows for the following functions: * Programming of the OTP array * Reading of memory registers SPI transfers follow CPOL = 0, CPHA = 0, MSB first convention. Figure 7 shows the SPI transfer timing, and Figure 45 shows the SPI transfer protocol. BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 SCLK CS DIN DOUT D15 D14 Figure 45. SPI Transfer Protocol The following operations are supported in DPM: * Register pointer write * Register pointer read * Register data write * Register data read * Acceleration data read 6.1 Communication Error Detection 6.1.1 Data Input Parity Detection All commands except for the DPM Entry command employ odd parity to ensure data integrity. For Read commands, the parity bit is located in bit D10, and the parity is calculated using bits D15 through D11. For Write commands, the parity bit is located in bit D9, and the parity is calculated using bits D15 through D0. If a parity error is detected, both the current and subsequent commands are ignored, and the parity fault response is transmitted during the subsequent SPI transfer. 6.1.2 Data Output Parity All responses except for the DPM entry response employ odd parity to ensure data integrity. Parity is calculated using the entire 16-bit message. 6.2 DPM Entry DPM can be activated at any time during the operation of the device, provided the SPI DPM Entry command is the first command transmitted. If an incorrect DPM Entry command is received, DPM is locked out, and cannot be activated until the device is reset. The device responds to the DPM Entry command with the logical complement of the received data as confirmation that it has been received correctly. Upon completion of a successful transfer DPM is activated. Once activated, the device will remain in DPM until a reset condition occurs. Following successful transmission of the DPM Entry command, DPM operations may be completed in any order. MMA51xxLW Sensors Freescale Semiconductor, Inc. 55 6.3 DPM Command/Response Summary Table 21 provides a summary of SPI commands and responses. Table 21. SPI Command/Response Summary Command SPI DPM Entry Register Pointer Write Register Pointer Read Register Data Write Register Data Read Acceleration Data Read Invalid Command Response (Waiting for SPI DPM Entry) Invalid Command Response Parity Fault Response (Subsequent Message Response) 6.4 Pin Bit D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 DIN 1 0 1 0 0 0 1 1 0 1 0 1 1 1 0 0 DOUT 0 1 0 1 1 1 0 0 1 0 1 0 0 0 1 1 DIN 0 1 0 0 1 1 P X A7 A6 A5 A4 A3 A2 A1 A0 DOUT 1 0 1 1 0 P 0 1 0 0 0 0 0 0 0 0 DIN 0 1 0 0 0 P=0 0 X X X X X X X X X DOUT 1 0 1 1 0 P 0 1 A7 A6 A5 A4 A3 A2 A1 A0 DIN 0 1 0 1 1 0 P X D7 D6 D5 D4 D3 D2 D1 D0 DOUT 1 0 1 0 0 P 1 0 A7 A6 A5 A4 A3 A2 A1 A0 DIN 0 1 0 1 0 P=1 0 X X X X X X X X X DOUT 1 0 1 0 0 P 1 0 D7 D6 D5 D4 D3 D2 D1 D0 DIN 0 1 1 0 0 P=1 0 0 0 0 0 0 0 0 0 0 DOUT 1 0 0 1 1 P D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 DIN 0 0 D[13] D[12] D[11] D[10] D[9] D[8] D[7] D[6] D[5] D[4] D[3] D[2] D[1] D[0] DOUT 1 D[2] D[1] D[0] D[2] D[1] D[0] DIN 0 DOUT 1 No Response (all 0s) - DPM Entry Locked Out 1 1 D[12] D[11] D[10] D[9] D[8] D[7] D[6] D[5] D[4] D[3] No Response (all 0s) - DPM Entry Locked Out DIN 1 1 DOUT 0 0 DIN 1 0 D[13] D[12] D[11] ... D[x] Not SPI DPM Entry Command DOUT 0 1 D[13] D[12] D[11] ... D[x] No Response (all 0s) - DPM Entry Locked Out DIN X X X X D[13] D[12] D[11] D[10] D[9] D[8] D[7] D[6] D[5] D[4] D[3] No Response (all 0s) - DPM Entry Locked Out X X X DOUT d[15] d[14] d[13] d[12] d[11] d[10] d[9] X X X X X X X X X d[8] d[7] d[6] d[5] d[4] d[3] d[2] d[1] d[0] DIN X X X X X X X X X X X X X X X X DOUT 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 Register Pointer Operations Access to internal registers is accomplished via a pointer register. The pointer contains the address of the register affected by register data write and read operations. Two register pointer operations are provided: Register Pointer Write, and Register Pointer Read. Command and response information is shown in Table 21. 6.5 Register Data Operations Two register operations are provided: Register Write, and Register Read. In each case, the address of the affected register is contained in the register pointer. 6.5.1 Register Write Command The Register Write command format is shown in Table 21. The least significant 8 bits of the Register Write command message contain the data to be written to the register pointed to by the register pointer. The least significant 8 bits of the Register Write response message contain the address of the register that was modified. The write to the register is executed during the clock cycle immediately after CS is deasserted. MMA51xxLW 56 Sensors Freescale Semiconductor, Inc. 6.5.2 Register Read Command The Register Read command format is shown in Table 21. The least significant 8 bits of the Register Read command message are ignored. The least significant 8 bits of the Register Read response message contain the contents of the register pointed to by the register pointer. 16 bit register reads are possible using consecutive Register Read commands. The high byte of a 16 bit register will automatically be frozen on a read of the low byte of the register. 6.5.3 Acceleration Data Read Operations The Acceleration Data Read command format is shown in Table 21. The response to this command provides either 8-bit, or 10-bit acceleration data depending on the state of the DATASIZE bit in the DEVCFG2 register. DATASIZE 6.5.4 6.5.4.1 Bit D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 DATASIZE = 1 (8-Bit Data) 1 0 0 1 1 P 0 0 D7 D6 D5 D4 D3 D2 D1 D0 DATASIZE = 0 (10-Bit Data) 1 0 0 1 1 P D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Error Responses Response to Invalid Commands Reference Table 21 for responses to Invalid Commands. 6.5.4.2 Parity Fault Response If the device detects a Command Parity fault, the current, and subsequent SPI commands are ignored and the device responds to the subsequent message with the Parity Fault response, as shown in Table 21. 6.6 SPI OTP Programming Procedure 1. Set VCC = VPP. 2. Enter SPI DPM. 3. Load desired data into the OTP shadow registers using SPI Write commands. a. Write the desired contents of DEVCFG2 ($05) to address $05 b. Write the desired contents of DEVCFG2 ($05) to address $1E c. Write the desired contents of DEVCFG3 ($06) to address $06 d. Write the desired contents of DEVCFG3 ($06) to address $1F e. Write the desired contents of DEVCFG4 ($07) to address $07 f. Write the desired contents of DEVCFG4 ($07) to address $20 g. Write the desired contents of DEVCFG5 ($08) to address $08 h. Write the desired contents of DEVCFG5 ($08) to address $21 i. Write the desired contents of DEVCFG6 ($09) to address $09 j. Write the desired contents of DEVCFG6 ($09) to address $22 k. Write the desired contents of DEVCFG7 ($0A) to address $0A l. Write the desired contents of DEVCFG7 ($0A) to address $23 m.Write the desired contents of DEVCFG8 ($0B) to address $0B n. Write the desired contents of DEVCFG8 ($0B) to address $24 o. Write the desired contents of MFG_ID ($0D) to address $0D p. Write the desired contents of MFG_ID ($0D) to address $2E 4. Write 0x05 to register $44 to initiate the NVM programming. 5. Delay a minimum of tPROG_ARRAY 6. Read the SC register and verify the IDEF_B flag is set (indicating the write is complete and successful). MMA51xxLW Sensors Freescale Semiconductor, Inc. 57 7 Package 7.1 Case Outline Drawing Reference Freescale Case Outline Drawing # 98ASA00090D http://www.freescale.com/files/shared/doc/package_info/98ASA00090D.pdf 7.2 Recommended Footprint Reference Freescale Application Note AN3111, latest revision: http://www.freescale.com/files/sensors/doc/app_note/AN3111.pdf MMA51xxLW 58 Sensors Freescale Semiconductor, Inc. 8 Revision History Table 22. Revision History Revision number Revision date 0 10/2014 * Initial data sheet. 1 03/2014 * Added the AXIS bit definition to the memory map. 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