Preliminary Information X4283/85 128K 16K x 8 Bit CPU Supervisor with 128K EEPROM FEATURES DESCRIPTION * Selectable watchdog timer * Low VCC detection and reset assertion --Four standard reset threshold voltages --Adjust low VCC reset threshold voltage using special programming sequence --Reset signal valid to VCC = 1V * Low power CMOS --<20A max standby current, watchdog on --<1A standby current, watchdog OFF --3mA active current * 128Kbits of EEPROM --64 byte page write mode --Self-timed write cycle --5ms write cycle time (typical) * Built-in inadvertent write protection --Power-up/power-down protection circuitry --Protect 0, 1/4, 1/2, all or 64, 128, 256 or 512 bytes of EEPROM array with programmable Block LockTM protection * 400kHz 2-wire interface * 2.7V to 5.5V power supply operation * Available packages --8-lead SOIC --8-lead TSSOP The X4283/85 combines four popular functions, Power-on Reset Control, Watchdog Timer, Supply Voltage Supervision, and Block Lock protect serial EEPROM memory in one package. This combination lowers system cost, reduces board space requirements, and increases reliability. Applying power to the device activates the power on reset circuit which holds RESET/RESET active for a period of time. This allows the power supply and oscillator to stabilize before the processor can execute code. The Watchdog Timer provides an independent protection mechanism for microcontrollers. When the microcontroller fails to restart a timer within a selectable time out interval, the device activates the RESET/ RESET signal. The user selects the interval from three preset values. Once selected, the interval does not change, even after cycling the power. The device's low VCC detection circuitry protects the user's system from low voltage conditions, resetting the system when VCC falls below the set minimum VCC trip point. RESET/RESET is asserted until VCC returns to proper operating level and stabilizes. Four industry BLOCK DIAGRAM Watchdog Transition Detector WP S0 S1 Data Register Command Decode & Control Logic VCC Threshold Reset logic Status Register EEPROM Array + VCC VTRIP REV 1.17 11/27/00 RESET (X4283) RESET (X4285) 8Kb 4Kb 4Kb SCL Protect Logic Block Lock Control SDA Watchdog Timer Reset - www.xicor.com Reset & Watchdog Timebase Power on and Low Voltage Reset Generation Characteristics subject to change without notice. 1 of 22 X4283/85 - Preliminary Information standard Vtrip thresholds are available, however, Xicor's unique circuits allow the threshold to be reprogrammed to meet custom requirements or to fine-tune the threshold for applications requiring higher precision. PIN CONFIGURATION The memory portion of the device is a CMOS Serial EEPROM array with Xicor's Block Lock protection. The array is internally organized as 64 bytes per page. The device features an 2-wire interface and software protocol allowing operation on an 2-wire bus. 8-Pin JEDEC SOIC S0 S1 RST/RST VSS 1 2 3 4 8 7 6 5 VCC WP SCL SDA 8-Pin TSSOP WP VCC S0 S1 1 2 3 4 8 7 6 5 SCL SDA VSS RST/RST PIN DESCRIPTION Pin (SOIC) Pin (TSSOP) Name 1 3 S0 Device Select Input 2 4 S1 Device Select Input 3 5 RESET/ RESET Function Reset Output. RESET/RESET is an active LOW/HIGH, open drain output which goes active whenever VCC falls below the minimum VCC sense level. It will remain active until VCC rises above the minimum VCC sense level for 250ms. RESET/ RESET goes active if the Watchdog Timer is enabled and SDA remains either HIGH or LOW longer than the selectable Watchdog time out period. A falling edge on SDA, while SCL is HIGH, resets the Watchdog Timer. RESET/RESET goes active on power up and remains active for 250ms after the power supply stabilizes. 4 6 VSS Ground 5 7 SDA Serial Data. SDA is a bidirectional pin used to transfer data into and out of the device. It has an open drain output and may be wire ORed with other open drain or open collector outputs. This pin requires a pull up resistor and the input buffer is always active (not gated). Watchdog Input. A HIGH to LOW transition on the SDA (while SCL is HIGH) restarts the Watchdog timer. The absence of a HIGH to LOW transition within the watchdog time out period results in RESET/RESET going active. 6 8 SCL Serial Clock. The Serial Clock controls the serial bus timing for data input and output. 7 1 WP Write Protect. WP HIGH used in conjunction with WPEN bit prevents writes to the control register. 8 2 VCC Supply Voltage REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 2 of 22 X4283/85 - Preliminary Information PRINCIPLES OF OPERATION Power On Reset Application of power to the X4283/85 activates a Power On Reset Circuit that pulls the RESET/RESET pin active. This signal provides several benefits. - It prevents the system microprocessor from starting to operate with insufficient voltage. - It prevents the processor from operating prior to stabilization of the oscillator. - It allows time for an FPGA to download its configuration prior to initialization of the circuit. - It prevents communication to the EEPROM, greatly reducing the likelihood of data corruption on power up. When VCC exceeds the device VTRIP threshold value for 200ms (nominal) the circuit releases RESET/ RESET allowing the system to begin operation. periodically, while SCL is HIGH (this is a start bit) prior to the expiration of the watchdog time out period to prevent a RESET/RESET signal. The state of two nonvolatile control bits in the Status Register determine the watchdog timer period. The microprocessor can change these watchdog bits, or they may be "locked" by tying the WP pin HIGH. EEPROM INADVERTENT WRITE PROTECTION When RESET/RESET goes active as a result of a low voltage condition or Watchdog Timer Time-Out, any inprogress communications are terminated. While RESET/RESET is active, no new communications are allowed and no nonvolatile write operation can start. Non-volatile writes in-progress when RESET/RESET goes active are allowed to finish. Additional protection mechanisms are provided with memory Block Lock and the Write Protect (WP) pin. These are discussed elsewhere in this document. LOW VOLTAGE MONITORING During operation, the X4283/85 monitors the VCC level and asserts RESET/RESET if supply voltage falls below a preset minimum VTRIP. The RESET/RESET signal prevents the microprocessor from operating in a power fail or brownout condition. The RESET/RESET signal remains active until the voltage drops below 1V. It also remains active until VCC returns and exceeds VTRIP for 200ms. VCC THRESHOLD RESET PROCEDURE The X4283/85 is shipped with a standard VCC threshold (VTRIP) voltage. This value will not change over normal operating and storage conditions. However, in applications where the standard VTRIP is not exactly right, or if higher precision is needed in the VTRIP value, the X4283/85 threshold may be adjusted. The procedure is described below, and uses the application of a nonvolatile control signal. WATCHDOG TIMER The Watchdog Timer circuit monitors the microprocessor activity by monitoring the SDA and SCL pins. The microprocessor must toggle the SDA pin HIGH to LOW Figure 1. Set VTRIP Level Sequence (VCC = desired VTRIP values WEL bit set) VP = 12-15V WP 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 SCL SDA A0h REV 1.17 11/27/00 00h 01h www.xicor.com 00h Characteristics subject to change without notice. 3 of 22 X4283/85 - Preliminary Information Setting the VTRIP Voltage This procedure is used to set the VTRIP to a higher or lower voltage value. It is necessary to reset the trip point before setting the new value. Resetting the VTRIP Voltage This procedure is used to set the VTRIP to a "native" voltage level. For example, if the current VTRIP is 4.4V and the new VTRIP must be 4.0V, then the VTRIP must be reset. When VTRIP is reset, the new VTRIP is something less than 1.7V. This procedure must be used to set the voltage to a lower value. To set the new VTRIP voltage, start by setting the WEL bit in the control register, then apply the desired VTRIP threshold voltage to the VCC pin and the programming voltage, VP, to the WP pin and 2 byte address and 1 byte of "00" data. The stop bit following a valid write operation initiates the VTRIP programming sequence. Bring WP LOW to complete the operation. To reset the new VTRIP voltage start by setting the WEL bit in the control register, apply VCC and the programming voltage, VP, to the WP pin and 2 byte address and 1 byte of "00" data. The stop bit of a valid write operation initiates the VTRIP programming sequence. Bring WP LOW to complete the operation. Figure 2. Reset VTRIP Level Sequence (VCC > 3V. WP = 12-15V, WEL bit set) VP = 12-15V WP 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 SCL SDA A0h 00h 03h 00h Figure 3. Sample VTRIP Reset Circuit VP SOIC Adjust 4.7K RESET VTRIP Adj. 1 2 3 4 C 8 X4283 7 6 5 Run SCL SDA REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 4 of 22 X4283/85 - Preliminary Information Figure 4. VTRIP Programming Sequence VTRIP Programming Execute Reset VTRIP Sequence Set VCC = VCC Applied = Desired VTRIP New VCC Applied = Old VCC Applied + Error Execute Set VTRIP Sequence New VCC Applied = Old VCC Applied - Error Apply 5V to VCC Execute Reset VTRIP Sequence Decrement VCC (VCC = VCC - 50mV) NO RESET pin goes active? YES Error -Emax Measured VTRIP Desired VTRIP Error Emax -Emax < Error < Emax DONE Emax = Maximum Allowed VTRIP Error Control Register The Control Register provides the user a mechanism for changing the Block Lock and Watchdog Timer settings. The Block Lock and Watchdog Timer bits are nonvolatile and do not change when power is removed. The Control Register is accessed at address FFFFh. It can only be modified by performing a byte write operation directly to the address of the register and only one data byte is allowed for each register write operation. REV 1.17 11/27/00 Prior to writing to the Control Register, the WEL and RWEL bits must be set using a two step process, with the whole sequence requiring 3 steps. See "Writing to the Control Register" below. The user must issue a stop after sending this byte to the register to initiate the nonvolatile cycle that stores WD1, WD0, BP2, BP1, and BP0. The X4283/85 will not acknowledge any data bytes written after the first byte is entered. www.xicor.com Characteristics subject to change without notice. 5 of 22 X4283/85 - Preliminary Information The state of the Control Register can be read at any time by performing a random read at address FFFFh. Only one byte is read by each register read operation. The X4283/85 resets itself after the first byte is read. The master should supply a stop condition to be consistent with the bus protocol, but a stop is not required to end this operation. 7 6 5 4 3 WPEN WD1 WD0 BP1 BP0 2 1 0 RWEL WEL BP2 RWEL: Register Write Enable Latch (Volatile) The RWEL bit must be set to "1" prior to a write to the Control Register. WEL: Write Enable Latch (Volatile) The WEL bit controls the access to the memory and to the Register during a write operation. This bit is a volatile latch that powers up in the LOW (disabled) state. While the WEL bit is LOW, writes to any address, including any control registers will be ignored (no acknowledge will be issued after the Data Byte). The WEL bit is set by writing a "1" to the WEL bit and zeroes to the other bits of the control register. Once set, WEL remains set until either it is reset to 0 (by writing a "0" to the WEL bit and zeroes to the other bits of the control register) or until the part powers up again. Writes to the WEL bit do not cause a nonvolatile write cycle, so the device is ready for the next operation immediately after the stop condition. BP2 BP1 BP0 BP2, BP1, BP0: Block Protect Bits (Nonvolatile) The Block Protect Bits, BP2, BP1 and BP0, determine which blocks of the array are write protected. A write to a protected block of memory is ignored. The block protect bits will prevent write operations to one of eight segments of the array. Protected Addresses (Size) 0 0 0 None (factory setting) None 0 0 1 3000h - 3FFFh (4K bytes) Upper 1/4 (Q4) 0 1 0 2000h - 3FFFh (8K bytes) Upper 1/2 (Q3,Q4) 0 1 1 0000h - 3FFFh (16K bytes) Full Array (All) 1 0 0 000h - 03Fh (64 bytes) First Page (P1) 1 0 1 000h - 07Fh (128 bytes) First 2 pgs (P2) 1 1 0 000h - 0FFh (256 bytes) First 4 pgs (P4) 1 1 1 000h - 1FFh (512 bytes) First 8 pgs (P8) REV 1.17 11/27/00 Array Lock WD1, WD0: Watchdog Timer Bits The bits WD1 and WD0 control the period of the Watchdog Timer. The options are shown below. WD1 WD0 Watchdog Time Out Period 0 0 1.4 seconds (factory setting) 0 1 600 milliseconds 1 0 200 milliseconds 1 1 disabled Write Protect Enable These devices have an advanced Block Lock scheme that protects one of eight blocks of the array when enabled. It provides hardware write protection through the use of a WP pin and a nonvolatile Write Protect Enable (WPEN) bit. Four of the 8 protected blocks match the original Block Lock segments and this protection scheme is fully compatible with the current devices using 2 bits of block lock control (assuming the BP2 bit is set to 0). The Write Protect (WP) pin and the Write Protect Enable (WPEN) bit in the Control Register control the programmable Hardware Write Protect feature. Hardware Write Protection is enabled when the WP pin and the WPEN bit are HIGH and disabled when either the WP pin or the WPEN bit is LOW. When the chip is Hardware Write Protected, nonvolatile writes as well as to the block protected sections in the memory array cannot be written. Only the sections of the memory array that are not block protected can be written. Note that since the WPEN bit is write protected, it cannot be changed back to a LOW state; so write protection is enabled as long as the WP pin is held HIGH. www.xicor.com Characteristics subject to change without notice. 6 of 22 X4283/85 - Preliminary Information Table 1. Write Protect Enable Bit and WP Pin Function WP WPEN Memory Array not Block Protected Memory Array Block Protected Block Protect Bits WPEN Bit Protection LOW X Writes OK Writes Blocked Writes OK Writes OK Software HIGH 0 Writes OK Writes Blocked Writes OK Writes OK Software HIGH 1 Writes OK Writes Blocked Writes Blocked Writes Blocked Hardware Writing to the Control Register Changing any of the nonvolatile bits of the control register requires the following steps: - Write a 02H to the Control Register to set the Write Enable Latch (WEL). This is a volatile operation, so there is no delay after the write. (Operation preceded by a start and ended with a stop). - Write a 06H to the Control Register to set both the Register Write Enable Latch (RWEL) and the WEL bit. This is also a volatile cycle. The zeros in the data byte are required. (Operation preceded by a start and ended with a stop). - Write a value to the Control Register that has all the control bits set to the desired state. This can be represented as 0xys t 01r in binary, where xy are the WD bits, and rst are the BP bits. (Operation preceded by a start and ended with a stop). Since this is a nonvolatile write cycle it will take up to 10ms to complete. The RWEL bit is reset by this cycle and the sequence must be repeated to change the nonvolatile bits again. If bit 2 is set to `1' in this third step (0xys t11r) then the RWEL bit is set, but the WD1, WD0, BP2, BP1 and BP0 bits remain unchanged. Writing a second byte to the control register is not allowed. Doing so aborts the write operation and returns a NACK. - A read operation occurring between any of the previous operations will not interrupt the register write operation. - The RWEL bit cannot be reset without writing to the nonvolatile control bits in the control register, power cycling the device or attempting a write to a write protected block. To illustrate, a sequence of writes to the device consisting of [02H, 06H, 02H] will reset all of the nonvolatile bits in the Control Register to 0. A sequence of [02H, 06H, 06H] will leave the nonvolatile bits unchanged and the RWEL bit remains set. SERIAL INTERFACE Serial Interface Conventions The device supports a bidirectional bus oriented protocol. The protocol defines any device that sends data onto the bus as a transmitter, and the receiving device as the receiver. The device controlling the transfer is called the master and the device being controlled is called the slave. The master always initiates data transfers, and provides the clock for both transmit and receive operations. Therefore, the devices in this family operate as slaves in all applications. Serial Clock and Data Data states on the SDA line can change only during SCL LOW. SDA state changes during SCL HIGH are reserved for indicating start and stop conditions. See Figure 5. Figure 5. Valid Data Changes on the SDA Bus SCL SDA Data Stable REV 1.17 11/27/00 Data Change www.xicor.com Data Stable Characteristics subject to change without notice. 7 of 22 X4283/85 - Preliminary Information Serial Start Condition All commands are preceded by the start condition, which is a HIGH to LOW transition of SDA when SCL is HIGH. The device continuously monitors the SDA and SCL lines for the start condition and will not respond to any command until this condition has been met. See Figure 6. Serial Stop Condition All communications must be terminated by a stop condition, which is a LOW to HIGH transition of SDA when SCL is HIGH. The stop condition is also used to place the device into the Standby power mode after a read sequence. A stop condition can only be issued after the transmitting device has released the bus. See Figure 6. Figure 6. Valid Start and Stop Conditions SCL SDA Start Stop Serial Acknowledge Acknowledge is a software convention used to indicate successful data transfer. The transmitting device, either master or slave, will release the bus after transmitting eight bits. During the ninth clock cycle, the receiver will pull the SDA line LOW to acknowledge that it received the eight bits of data. Refer to Figure 7. The device will respond with an acknowledge after recognition of a start condition and if the correct Device Identifier and Select bits are contained in the Slave Address Byte. If a write operation is selected, the device will respond with an acknowledge after the receipt of each subsequent eight bit word. The device will acknowledge all incoming data and address bytes, except for the Slave Address Byte when the Device Identifier and/or Select bits are incorrect. In the read mode, the device will transmit eight bits of data, release the SDA line, then monitor the line for an acknowledge. If an acknowledge is detected and no stop condition is generated by the master, the device will continue to transmit data. The device will terminate further data transmissions if an acknowledge is not detected. The master must then issue a stop condition to return the device to Standby mode and place the device into a known state. Figure 7. Acknowledge Response from Receiver SCL from Master 1 8 9 Data Output from Transmitter Data Output from Receiver START REV 1.17 11/27/00 Acknowledge www.xicor.com Characteristics subject to change without notice. 8 of 22 X4283/85 - Preliminary Information Serial Write Operations data. After receiving the 8 bits of the Data Byte, the device again responds with an acknowledge. The master then terminates the transfer by generating a stop condition, at which time the device begins the internal write cycle to the nonvolatile memory. During this internal write cycle, the device inputs are disabled, so the device will not respond to any requests from the master. The SDA output is at high impedance. See Figure 8. BYTE WRITE For a write operation, the device requires the Slave Address Byte and a Word Address Byte. This gives the master access to any one of the words in the array. After receipt of the Word Address Byte, the device responds with an acknowledge, and awaits the next eight bits of Figure 8. Byte Write Sequence S t a r t Signals from the Master SDA Bus Slave Address 10 1 0 Word Address Byte 1 S t o p Data 0 A C K A C K Signals from the Slave Word Address Byte 0 A write to a protected block of memory will suppress the acknowledge bit. A C K A C K one. The page address remains constant. When the counter reaches the end of the page, it "rolls over" and goes back to `0' on the same page. This means that the master can write 64 bytes to the page starting at any location on that page. If the master begins writing at location 60, and loads 12 bytes, then the first 4 bytes are written to locations 60 through 63, and the last 8 bytes are written to locations 0 through 7. Afterwards, the address counter would point to location 8 of the page that was just written. If the master supplies more than 64 bytes of data, then new data over-writes the previous data, one byte at a time. Page Write The device is capable of a page write operation. It is initiated in the same manner as the byte write operation; but instead of terminating the write cycle after the first data byte is transferred, the master can transmit an unlimited number of 8-bit bytes. After the receipt of each byte, the device will respond with an acknowledge, and the address is internally incremented by Figure 9. Page Write Operation Signals from the Master S t a r t (1 < n < 64) Word Address Byte 0 Word Address Byte 1 Slave Address Data (1) S t o p Data (n) SDA Bus 1 0 1 0 Signals from the Slave REV 1.17 11/27/00 0 A C K A C K www.xicor.com A C K A C K A C K Characteristics subject to change without notice. 9 of 22 X4283/85 - Preliminary Information Figure 10. Writing 12 bytes to a 64-byte page starting at location 60. 8 Bytes Address =7 4 Bytes Address Pointer Ends Here Addr = 8 The master terminates the Data Byte loading by issuing a stop condition, which causes the device to begin the nonvolatile write cycle. As with the byte write operation, all inputs are disabled until completion of the internal write cycle. See Figure 9 for the address, acknowledge, and data transfer sequence. Address 60 Figure 11. Acknowledge Polling Sequence Stops and Write Modes Stop conditions that terminate write operations must be sent by the master after sending at least 1 full data byte plus the subsequent ACK signal. If a stop is issued in the middle of a data byte, or before 1 full data byte plus its associated ACK is sent, then the device will reset itself without performing the write. The contents of the array will not be effected. Acknowledge Polling The disabling of the inputs during nonvolatile cycles can be used to take advantage of the typical 5ms write cycle time. Once the stop condition is issued to indicate the end of the master's byte load operation, the device initiates the internal nonvolatile cycle. Acknowledge polling can be initiated immediately. To do this, the master issues a start condition followed by the Slave Address Byte for a write or read operation. If the device is still busy with the nonvolatile cycle then no ACK will be returned. If the device has completed the write operation, an ACK will be returned and the host can then proceed with the read or write operation. Refer to the flow chart in Figure 11. REV 1.17 11/27/00 Address n-1 www.xicor.com Byte Load Completed by Issuing STOP. Enter ACK Polling Issue START Issue Slave Address Byte (Read or Write) Issue STOP NO ACK returned? YES Nonvolatile Cycle Complete. Continue Command Sequence? NO Issue STOP YES Continue Normal Read or Write Command Sequence PROCEED Characteristics subject to change without notice. 10 of 22 X4283/85 - Preliminary Information Serial Read Operations Read operations are initiated in the same manner as write operations with the exception that the R/W bit of the Slave Address Byte is set to one. There are three basic read operations: Current Address Reads, Random Reads, and Sequential Reads. Upon receipt of the Slave Address Byte with the R/W bit set to one, the device issues an acknowledge and then transmits the eight bits of the Data Byte. The master terminates the read operation when it does not respond with an acknowledge during the ninth clock and then issues a stop condition. Refer to Figure 12 for the address, acknowledge, and data transfer sequence. Current Address Read Internally the device contains an address counter that maintains the address of the last word read incremented by one. Therefore, if the last read was to address n, the next read operation would access data from address n+1. On power up, the address of the address counter is undefined, requiring a read or write operation for initialization. It should be noted that the ninth clock cycle of the read operation is not a "don't care." To terminate a read operation, the master must either issue a stop condition during the ninth cycle or hold SDA HIGH during the ninth clock cycle and then issue a stop condition. Figure 12. Current Address Read Sequence Signals from the Master SDA Bus S t a r t S t o p Slave Address 1 0 1 0 1 A C K Signals from the Slave Random Read Random read operation allows the master to access any memory location in the array. Prior to issuing the Slave Address Byte with the R/W bit set to one, the master must first perform a "dummy" write operation. The master issues the start condition and the Slave Address Byte, receives an acknowledge, then issues the Word Address Bytes. After acknowledging receipts Data of the Word Address Bytes, the master immediately issues another start condition and the Slave Address Byte with the R/W bit set to one. This is followed by an acknowledge from the device and then by the eight bit word. The master terminates the read operation by not responding with an acknowledge and then issuing a stop condition. Refer to Figure 13 for the address, acknowledge, and data transfer sequence. Figure 13. Random Address Read Sequence Signals from the Master SDA Bus Signals from the Slave REV 1.17 11/27/00 S t a r t Word Address Byte 1 Slave Address 1 0 1 0 S t a r t Word Address Byte 0 0 S t o p Slave Address 1 A C K A C K www.xicor.com A C K A C K Data Characteristics subject to change without notice. 11 of 22 X4283/85 - Preliminary Information There is a similar operation, called "Set Current Address" where the device does no operation, but enters a new address into the address counter if a stop is issued instead of the second start shown in Figure 13. The device goes into standby mode after the stop and all bus activity will be ignored until a start is detected. The next Current Address Read operation reads from the newly loaded address. This operation could be useful if the master knows the next address it needs to read, but is not ready for the data. Sequential Read Sequential reads can be initiated as either a current address read or random address read. The first Data Byte is transmitted as with the other modes; however, the master now responds with an acknowledge, indicating it requires additional data. The device continues to output data for each acknowledge received. The master terminates the read operation by not responding with an acknowledge and then issuing a stop condition. The data output is sequential, with the data from address n followed by the data from address n + 1. The address counter for read operations increments through all page and column addresses, allowing the entire memory contents to be serially read during one operation. At the end of the address space the counter "rolls over" to address 0000H and the device continues to output data for each acknowledge received. Refer to Figure 14 for the acknowledge and data transfer sequence. Figure 14. Sequential Read Sequence Signals from the Master SDA Bus Signals from the Slave Slave Address A C K S t o p A C K A C K 1 A C K Data (2) Data (1) Data (n-1) Data (n) (n is any integer greater than 1) X4283/85 Addressing SLAVE ADDRESS BYTE Following a start condition, the master must output a Slave Address Byte. This byte consists of several parts: - a device type identifier that is `1010' to access the array - one bits of `0'. - next two bits are the device address. - After loading the entire Slave Address Byte from the SDA bus, the device compares the input slave byte data to the proper slave byte. Upon a correct compare, the device outputs an acknowledge on the SDA line. Word Address The word address is either supplied by the master or obtained from an internal counter. The internal counter is undefined on a power up condition. - one bit of the slave command byte is a R/W bit. The R/W bit of the Slave Address Byte defines the operation to be performed. When the R/W bit is a one, then a read operation is selected. A zero selects a write operation. Refer to Figure 15. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 12 of 22 X4283/85 - Preliminary Information Figure 15. X4283/85 Addressing Device Identifier 1 0 1 Device Select 0 0 S1 S0 R/W Slave Address Byte High Order Word Address 0 A13 (X7) 0 A12 (X6) A11 (X5) A10 (X4) A9 (X3) A8 (X2) A1 (Y1) A0 (Y0) D1 D0 Word Address Byte 0-128K Low Order Word Address A7 (X1) A6 (X0) A5 (Y5) A4 (Y4) A3 (Y3) A2 (Y2) Word Address Byte 0 for all Options D7 D6 D5 D4 D3 D2 Data Byte for all Options Operational Notes The device powers-up in the following state: - Communication to the device is inhibited while RESET/RESET is active and any in-progress communication is terminated. - The device is in the low power standby state. - The WEL bit is set to `0'. In this state it is not possible to write to the device. - Block Lock bits can protect sections of the memory array from write operations. SYMBOL TABLE - SDA pin is the input mode. - RESET/RESET Signal is active for tPURST. INPUTS OUTPUTS Data Protection The following circuitry has been included to prevent inadvertent writes: WAVEFORM Must be steady Will be steady - The WEL bit must be set to allow write operations. May change from LOW to HIGH Will change from LOW to HIGH - The proper clock count and bit sequence is required prior to the stop bit in order to start a nonvolatile write cycle. May change from HIGH to LOW Will change from HIGH to LOW - A three step sequence is required before writing into the Control Register to change Watchdog Timer or Block Lock settings. Don't Care: Changes Allowed N/A Changing: State Not Known Center Line is High Impedance - The WP pin, when held HIGH, and WPEN bit at logic HIGH will prevent all writes to the Control Register. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 13 of 22 X4283/85 - Preliminary Information ABSOLUTE MAXIMUM RATINGS COMMENT Temperature under bias ................... -65C to +135C Storage temperature ........................ -65C to +150C Voltage on any pin with respect to VSS .......................................-1.0V to +7V D.C. output current ............................................... 5mA Lead temperature (soldering, 10 seconds).........300C Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only; functional operation of the device (at these or any other conditions above those listed in the operational sections of this specification) is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS Option Supply Voltage Limits Temperature Min. Max. Commercial 0C 70C -2.7 and -2.7A 2.7V to 5.5V +85C Blank and -4.5A 4.5V to 5.5V Industrial -40C D.C. OPERATING CHARACTERISTICS (Over the recommended operating conditions unless otherwise specified.) VCC = 2.7 to 5.5V Symbol Max Unit Test Conditions Active Supply Current Read 1.0 mA Active Supply Current Write 3.0 mA VIL = VCC x 0.1, VIH = VCC x 0.9 fSCL = 400kHz, SDA = Commands Standby Current DC (WDT off) 1 A VSDA = VSCL = VSB Others = GND or VSB Standby Current DC (WDT on) 20 A VSDA = VSCL = VSB Others = GND or VSB ILI Input Leakage Current 10 A VIN = GND to VCC ILO Output Leakage Current 10 A VSDA = GND to VCC Device is in Standby(2) -0.5 VCC x 0.3 V VCC +0.5 V (1) (1) (2) ISB1 ISB2(2) ICC1 ICC2 VIL(3) (3) Parameter Input LOW Voltage Min VIH Input nonvolatile VCC x 0.7 VHYS Schmitt Trigger Input Hysteresis Fixed input level VCC related level 0.2 .05 x VCC VOL Output LOW Voltage V V 0.4 V IOL = 3.0mA (2.7-5.5V) Notes: (1) The device enters the Active state after any start, and remains active until: 9 clock cycles later if the Device Select Bits in the Slave Address Byte are incorrect; 200ns after a stop ending a read operation; or tWC after a stop ending a write operation. (2) The device goes into Standby: 200ns after any stop, except those that initiate a nonvolatile write cycle; t WC after a stop that initiates a nonvolatile cycle; or 9 clock cycles after any start that is not followed by the correct Device Select Bits in the Slave Address Byte. (3) VIL Min. and VIH Max. are for reference only and are not tested. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 14 of 22 X4283/85 - Preliminary Information CAPACITANCE (TA = 25C, f = 1.0 MHz, VCC = 5V) Symbol COUT(4) (4) CIN Note: Parameter Max. Unit Test Conditions Output Capacitance (SDA, RST/RST) 8 pF VOUT = 0V Input Capacitance (SCL, WP) 6 pF VIN = 0V (4) This parameter is periodically sampled and not 100% tested. EQUIVALENT A.C. LOAD CIRCUIT A.C. TEST CONDITIONS 5V 1533 SDA or RESET For VOL = 0.4V and IOL = 3 mA Input pulse levels 0.1 VCC to 0.9 VCC Input rise and fall times 10ns Input and output timing levels 0.5VCC Output load Standard output load 100pF A.C. CHARACTERISTICS (Over recommended operating conditions, unless otherwise specified) Symbol Min. Max. Unit SCL Clock Frequency 0 400 kHz tIN Pulse width Suppression Time at inputs 50 tAA SCL LOW to SDA Data Out Valid 0.1 tBUF Time the bus free before start of new transmission 1.3 s tLOW Clock LOW Time 1.3 s tHIGH Clock HIGH Time 0.6 s tSU:STA Start Condition Setup Time 0.6 s tHD:STA Start Condition Hold Time 0.6 s tSU:DAT Data In Setup Time 100 ns tHD:DAT Data In Hold Time 0 s tSU:STO Stop Condition Setup Time 0.6 s Data Output Hold Time 50 ns fSCL tDH tR tF tSU:WP tHD:WP Cb Parameter SDA and SCL Rise Time SDA and SCL Fall Time 0.9 s 20 +.1Cb(6) 300 ns 20 +.1Cb(6) 300 ns WP Setup Time 0.6 WP Hold Time 0 Capacitive load for each bus line ns s s 400 pF Notes: (5) Typical values are for TA = 25C and VCC = 5.0V (6) Cb = total capacitance of one bus line in pF. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 15 of 22 X4283/85 - Preliminary Information TIMING DIAGRAMS Bus Timing tF tHIGH SCL tR tLOW tSU:DAT tSU:STA tHD:DAT tHD:STA SDA IN tSU:STO tAA tDH tBUF SDA OUT WP Pin Timing START SCL Clk 1 Clk 9 Slave Address Byte SDA IN tSU:WP tHD:WP WP Write Cycle Timing SCL SDA 8th Bit of Last Byte ACK tWC Stop Condition Start Condition Nonvolatile Write Cycle Timing Symbol (1) tWC Note: Parameter Min. Write Cycle Time Typ.(1) Max. Unit 5 10 ms (1) tWC is the time from a valid stop condition at the end of a write sequence to the end of the self-timed internal nonvolatile write cycle. It is the minimum cycle time to be allowed for any nonvolatile write by the user, unless Acknowledge Polling is used. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 16 of 22 X4283/85 - Preliminary Information Power-Up and Power-Down Timing VTRIP VCC tPURST 0 Volts tR tPURST tF tRPD VRVALID RESET (X4285) VRVALID RESET (X4283) RESET Output Timing Symbol Parameter Min. Typ. Max. Unit VTRIP Reset Trip Point Voltage, X4283/85-4.5A Reset Trip Point Voltage, X4283/85 Reset Trip Point Voltage, X4283/85-2.7A Reset Trip Point Voltage, X4283/85-2.7 4.5 4.25 2.85 2.55 4.62 4.38 2.92 2.62 4.75 4.5 3.0 2.7 V tPURST Power-up Reset Time out 100 250 400 ms 500 ns (8) VCC Detect to Reset/Output tRPD (8) VCC Fall Time 100 s (8) VCC Rise Time 100 s 1 V tF tR Reset Valid VCC VRVALID Note: (8) This parameter is periodically sampled and not 100% tested. SDA vs. RESET Timing tRSP tRSP<tWDO tRSP>tWDO tRSP>tWDO tRST tRST SCL SDA RESET Note: All inputs are ignored during the active reset period (tRST). REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 17 of 22 X4283/85 - Preliminary Information RESET Output Timing Symbol Parameter tWDO tRST Min. Typ. Max. Unit Watchdog Time Out Period, WD1 = 1, WD0 = 0 WD1 = 0, WD0 = 1 WD1 = 0, WD0 = 0 (factory setting) 100 450 1 250 650 1.5 400 850 2 ms ms sec Reset Time Out 100 250 400 ms VTRIP Programming Timing Diagram (WEL = 1) VCC (VTRIP) VTRIP tTSU tTHD VP WP tVPH tVPS tVPO SCL tRP SDA A0h 00h 01h or 03h 00h VTRIP Programming Parameters Parameter Description Min. Max. Unit tVPS VTRIP Program Enable Voltage Setup time 1 s tVPH VTRIP Program Enable Voltage Hold time 1 s tTSU VTRIP Setup time 1 s tTHD VTRIP Hold (stable) time 10 tWC VTRIP Write Cycle Time tVPO VTRIP Program Enable Voltage Off time (Between successive adjustments) 0 s tRP VTRIP Program Recovery Period (Between successive adjustments) 10 ms VP Programming Voltage 15 18 V VTRIP Programmed Voltage Range 2.55 4.75 V Vta1 Initial VTRIP Program Voltage accuracy (VCC applied-VTRIP) (Programmed at 25C.) -0.1 +0.4 V Vta2 Subsequent VTRIP Program Voltage accuracy [(VCC applied-Vta1)--VTRIP. Programmed at 25C.) -25 +25 mV Vtr VTRIP Program Voltage repeatability (Successive program operations. Programmed at 25C.) -25 +25 mV Vtv VTRIP Program variation after programming (0-75C). (Programmed at 25C.) -25 +25 mV VTRAN ms 10 ms VTRIP programming parameters are periodically sampled and are not 100% tested. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 18 of 22 X4283/85 - Preliminary Information PACKAGING INFORMATION 8-Lead Plastic Small Outline Gull Wing Package Type S 0.150 (3.80) 0.228 (5.80) 0.158 (4.00) 0.244 (6.20) Pin 1 Index Pin 1 0.014 (0.35) 0.019 (0.49) 0.188 (4.78) 0.197 (5.00) (4X) 7 0.053 (1.35) 0.069 (1.75) 0.004 (0.19) 0.010 (0.25) 0.050 (1.27) 0.010 (0.25) X 45 0.020 (0.50) 0.050"Typical 0.050" Typical 0 - 8 0.0075 (0.19) 0.010 (0.25) 0.250" 0.016 (0.410) 0.037 (0.937) 0.030" Typical 8 Places FOOTPRINT NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 19 of 22 X4283/85 - Preliminary Information PACKAGING INFORMATION 8-Lead Plastic, TSSOP, Package Type V .025 (.65) BSC .169 (4.3) .252 (6.4) BSC .177 (4.5) .114 (2.9) .122 (3.1) .047 (1.20) .0075 (.19) .0118 (.30) .002 (.05) .006 (.15) .010 (.25) Gage Plane 0 - 8 Seating Plane .019 (.50) .029 (.75) (4.16) (7.72) Detail A (20X) (1.78) .031 (.80) .041 (1.05) (0.42) (0.65) All Measurements Are Typical See Detail "A" NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 20 of 22 X4283/85 - Preliminary Information Ordering Information VCC Range VTRIP Range Package 4.5-5.5V 4.5-4.75 8L SOIC 8L TSSOP 4.5-5.5V 4.25-4.5 8L SOIC 8L TSSOP 2.7-5.5V 2.85-3.0 8L SOIC 8LTSSOP 2.7-5.5V 2.55-2.7 8L SOIC 8L TSSOP Operating Temperature Range Part Number RESET (Active LOW) Part Number RESET (Active HIGH) 0C-70C X4283S8-4.5A X4285S8-4.5A -40C-85C X4283S8I-4.5A X4285S8I-4.5A 0C-70C X4283V8-4.5A X4285V8-4.5A -40C-85C X4283V8I-4.5A X4285V8I-4.5A 0C-70C X4283S8 X4285S8 -40C-85C X4283S8I X4285S8I 0C-70C X4283V8 X4285V8 -40C-85C X4283V8I X4285V8I 0C-70C X4283S8-2.7A X4285S8-2.7A -40C-85C X4283S8I-2.7A X4285S8I-2.7A 0C-70C X4283V8-2.7A X4285V8-2.7A -40C-85C X4283V8I-2.7A X4285V8I-2.7A 0C-70C X4283S8-2.7 X4285S8-2.7 -40C-85C X4283S8I-2.7 X4285S8I-2.7 0C-70C X4283V8-2.7 X4285V8-2.7 -40C-85C X4283V8I-2.7 X4285V8I-2.7 Part Mark Information 8-Lead SOIC 8-Lead TSSOP X4283/85 X XX EYWW XXXXX AL = -4.5A (0 to +70C) AM = -4.5A (-40 to +85C) Blank = No Suffix (0 to +70C) I = No Suffix (-40 to +85C) AN = -2.7A (0 to +70C) AP = -2.7A (-40 to +85C) F = -2.7 (0 to +70C) G = -2.7 (-40 to +85C) ADB/ADK = -4.5A (0 to +70C) ADD/ADM = No Suffix (0 to +70C) ADF/ADO = -2.7A (0 to +70C) ADH/ADQ = -2.7 (0 to +70C) 4283/4285 REV 1.17 11/27/00 Blank = 8-Lead SOIC www.xicor.com Characteristics subject to change without notice. 21 of 22 X4283/85 - Preliminary Information LIMITED WARRANTY (c)Xicor, Inc. 2000 Patents Pending Devices sold by Xicor, Inc. are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Xicor, Inc. makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Xicor, Inc. makes no warranty of merchantability or fitness for any purpose. Xicor, Inc. reserves the right to discontinue production and change specifications and prices at any time and without notice. Xicor, Inc. assumes no responsibility for the use of any circuitry other than circuitry embodied in a Xicor, Inc. product. No other circuits, patents, or licenses are implied. TRADEMARK DISCLAIMER: Xicor and the Xicor logo are registered trademarks of Xicor, Inc. AutoStore, Direct Write, Block Lock, SerialFlash, MPS, and XDCP are also trademarks of Xicor, Inc. All others belong to their respective owners. U.S. PATENTS Xicor products are covered by one or more of the following U.S. Patents: 4,326,134; 4,393,481; 4,404,475; 4,450,402; 4,486,769; 4,488,060; 4,520,461; 4,533,846; 4,599,706; 4,617,652; 4,668,932; 4,752,912; 4,829,482; 4,874,967; 4,883,976; 4,980,859; 5,012,132; 5,003,197; 5,023,694; 5,084,667; 5,153,880; 5,153,691; 5,161,137; 5,219,774; 5,270,927; 5,324,676; 5,434,396; 5,544,103; 5,587,573; 5,835,409; 5,977,585. Foreign patents and additional patents pending. LIFE RELATED POLICY In situations where semiconductor component failure may endanger life, system designers using this product should design the system with appropriate error detection and correction, redundancy and back-up features to prevent such an occurrence. Xicor's products are not authorized for use in critical components in life support devices or systems. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. REV 1.17 11/27/00 www.xicor.com Characteristics subject to change without notice. 22 of 22