High-performance SiS645/650 Pentium® 4-Clock Synthesize
r
CY28342
Rev 1.0, November 20, 2006 Page 1 of 21
2200 Laurelwood Road, Santa Clara, CA 95054 Tel:(408) 855-0555 Fax:(408) 855-0550 www.SpectraLinear.com
Features
Supports Pentium£ 4-type CPUs
3.3V power supply
Eight copies of PCI clocks
One 48 MHz USB clock
Two copies of ZCLK clocks
One 48 MHz/24MHz programmable SIO clock
Two differential CPU clock pairs
SMBus support with read-back capabilities
Spread Spectrum EMI reduction
Dial-a-Frequency® features
Dial-a-Ratio™ features
Dial-a-dB® features
48-pin SSOP and TSSOP packages
Watchdog Function
Note:
1. Pins marked with [*] have internal pull-up resistors. Pins marked with [**] have internal pull-down resistors.
Block Diagram Pin Configuration[1]
PLL1
PLL2
/2
WD
Logic
XIN
XOUT
CPU_STP#
IREF
FS(0:4)
MULT0
VTTPWRGD
PCI_STP#
PD#
SDATA
SCLK
48M_24M#
48M
PCI_F(0:1)
PCI(0:5)
ZCLK(0:1)
AGP(0:1)
CPU(0:1)C
CPU(0:1)T
REF(0:2)
I2C
Logic
SRESET#
Power
on
Latch
SDCLK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
VDDSD
SDCLK
VSSSD
CPU_STP#*
CPU1T
CPU1C
VDDC
VSSC
CPU0T
CPU0C
IREF
VSSA
VDDA
SCLK
SDATA
PD#/VTTPWRGD*
VSSAGP
AGP0
AGP1
VDDAGP
VDD48M
48M
24_48M/MULT0*
VSS48M
VDDR
**FS0/REF0
**FS1/REF1
**FS2/REF2
VSSR
XIN
XOUT
VSSZ
ZCLK0
ZCLK1
VDDZ
*SRESET#/PCI_STP#
VDDP
**FS3/PCI_F0
PCI0
**FS4/PCI_F1
PCI1
VSSP
VDDP
PCI2
PCI3
PCI4
PCI5
VSSP
CY28342
48 Pin SSOP andf TSSOP
CY28342
Rev 1.0, November 20, 2006 Page 2 of 21
Table 1. Frequency Table
FS(4:0) CPU (MHz) SDRAM (MHz) ZCLK (MHz) AGP (MHz) PCI (MHz) VCO (MHz)
00000 100.20 100.20 66.80 66.80 33.40 400.8
00001 133.45 133.45 66.73 66.73 33.365 533.8
00010 100.20 133.60 66.80 66.80 33.40 400.8
00011 133.45 100.09 66.73 66.73 33.365 400.4
00100 100.20 167.00 62.63 62.63 31.315 501.0
00101 133.33 166.66 66.67 66.67 33.335 666.7
00110 100.20 150.30 66.80 66.80 33.40 601.2
00111 133.33 66.67 66.67 66.67 33.335 533.3
01000 100.20 120.24 66.80 66.80 33.40 601.2
01001 145.00 145.00 64.44 64.44 32.22 580.0
01010 111.11 133.33 66.67 66.67 33.335 666.7
01011 166.60 133.28 66.64 66.64 32.22 666.4
01100 66.80 66.80 66.80 66.80 33.40 400.8
01101 66.80 66.80 50.10 50.10 25.05 400.8
01110 100.20 133.60 100.20 66.80 33.40 400.8
01111 100.20 133.60 80.16 66.80 33.40 400.8
10000 100.20 167.00 83.50 62.63 31.315 501.0
10001 100.20 167.00 100.20 62.63 31.315 501.0
10010 102.20 136.27 68.13 68.13 34.065 408.8
10011 133.40 200.10 66.70 66.70 33.35 400.2
10100 105.00 140.00 70.00 70.00 35.00 420.0
10101 83.33 138.89 69.44 69.44 34.72 416.6
10110 108.00 144.00 72.00 72.00 36.00 432.0
10111 83.33 104.16 69.44 69.44 34.72 416.6
11000 116.00 145.00 64.44 64.44 32.22 580.0
11001 83.33 166.67 62.50 62.50 31.25 500.0
11010 120.00 150.00 66.67 66.67 33.335 600.0
11011 95.00 142.50 63.33 63.33 31.665 570.0
11100 112.00 140.00 62.22 62.22 31.11 560.0
11101 75.00 125.00 62.50 62.50 31.25 375.0
11110 108.00 180.00 67.50 67.50 33.75 540.0
11111 95.00 158.33 79.17 79.17 39.585 475.0
CY28342
Rev 1.0, November 20, 2006 Page 3 of 21
Pin Description [2]
Pin Name PWR I/O Description
6XIN IOscillator buffer input. Connect to a crystal or to an external clock.
7 XOUT VDDR O Oscillator buffer output. Connect to a crystal. Do not connect when
an external clock is applied at XIN.
39,40,43,44 CPU (0:1)T,
CPU (0:1)C
VDDC O Differential host output clock pairs. See Tabl e 1 for frequencies and
functionality.
16,17,20,23 PCI (0:5) VDDP O PCI clock outputs. See Table 1.
14 FS3/PCI_F0 VDDP I/O
PD
Power-on bidirectional Input/Output (I/O). At power-up, FS3 is the
input. When VTTPWRGD transitions to a logic HIGH, FS3 state is
latched and this pin becomes PCI_F0 clock output. See Table 1.
15 FS4/PCI_F1 VDDP I/O
PD
Power-on bidirectional I/O. At power-up, FS4 is the input. When
VTTPWRGD transitions to a logic HIGH, FS4 state is latched and this
pin becomes PCI_F1 Clock Output. See Table 1.
2 FS0/REF0 VDDR I/O
PD
Power-on bidirectional I/O. At power-up, FS0 is the input. When
VTTPWRGD transitions to a logic HIGH, FS0 state is latched and this
pin becomes REF0, buffered Output copy of the device’s XIN clock.
3 FS1/REF1 VDDR I/O
PD
Power-on bidirectional I/O. At power-up, FS1 is the input. When
VTTPWRGD is transited to logic LOW, FS1 state is latched and this pin
becomes REF1, buffered Output copy of the device’s XIN clock.
4 FS2/REF2 VDDR I/O
PD
Power-on bidirectional I/O. At power-up, FS2 is the input. When
VTTPWRGD is transited to logic LOW, FS2 state is latched and this pin
becomes REF2, buffered Output copy of the device’s XIN clock.
38 IREF I Current reference programming input for CPU buffers. A resistor is
connected between this pin and VSS. See Figure 8.
33 PD#/VTTPR
GD
I
PU
Power-down input/VTT power good input. At power-up, VTTPWRGD
is the input. When this input is transitions initially from LOW to HIGH,
the FS (0:4) and MULT0 are latched. After the first LOW-to-HIGH
transition, this pin becomes a PD# input with an internal pull-up. When
PD# is asserted LOW, the device enters power-down mode. See power
management function.
27 48M VDD48M O Fixed 48-MHz USB clock output.
26 24_48M/MUL
T0
VDD48M I/O
PU
Power-on bidirectional I/O. At power-up, MULT0 is the input. When
VTTPWRGD is transitions to logic HIGH MULT0 state is latched and this
pin becomes 24_48M, SIO programmable clock output.
9,10 ZCLK (0:1) VDDZ O HyperZip Clock Outputs. See Table 1.
34 SDATA I/O Serial Data Input. Conforms to the SMBus specification of a Slave
Receive/Transmit device. It is an input when receiving data, and an open
drain output when acknowledging or transmitting data.
35 SCLK I Serial Clock Input. Conforms to the SMBus specification.
12 SRESET# O PCI Clock Disable Input. If Byte12 Bit7 = 0, this pin becomes an
SRESET# open drain output, and the internal pull-up is not active. See
system reset description.
PCI_STP# I
PU
System Reset Control Output. If Byte12 Bit7 = 1 (Default), this pin
becomes PCI Clock Disable Input. When PCI_STP# is asserted LOW,
PCI (0:5) clocks are synchronously disabled in a LOW state. This pin
does not affect PCI_F (0:1) if they are programmed to be free-running
clocks via the device’s SMBus interface.
45 CPU_STP# I
PU
CPU Clock Disable Input. When asserted LOW, CPU (0:1)T clocks are
synchronously disabled in a HIGH state and CPU (0:1)C clocks are
synchronously disabled in a LOW state.
CY28342
Rev 1.0, November 20, 2006 Page 4 of 21
Serial Data Interface
To enhance the flexibility and function of the clock synthesizer,
a two-signal serial interface is provided. Through the Serial
Data Interface (SDI), various device functions such as
individual clock output buffers, etc., can be individually
enabled or disabled.
The registers associated with the SDI initializes to their default
setting upon power-up, and therefore the use of this interface
is optional. Clock device register changes are normally made
upon system initialization, if any are required. The interface
can also be used during system operation for power
management functions.
Data Protocol
The clock driver serial protocol accepts byte Write, byte Read,
block Write, and block Read operations from the controller. For
a block Write/Read operation, the bytes must be accessed in
sequential order from lowest to highest byte (most significant
bit first) with the ability to stop after any complete byte has
been transferred. For byte Write and byte Read operations,
the system controller can access individual indexed bytes. The
offset of the indexed byte is encoded in the command code,
as described in Table 2.
The block Write and block Read protocol is outlined in Table 3
while Ta bl e 4 outlines the corresponding byte Write and byte
Read protocol.
The slave receiver address is 11010010 (D2h).
Note:
2. PU = Internal pull-up. PD = internal pull-down. T = Tri-level logic input with valid logic voltages of LOW = < 0.8V, T = 1.0 –1.8V, and HIGH = > 2.0V.
47 SDCLK VDDSD O SDRAM Clock Output.
30,31 AGP (0:1) VDDAGP O AGP Clock Outputs. See Table 1 for frequencies and functionality.
48 VDDSD PWR 3.3V power supply for SDRAM clock output.
29 VDDAGP PWR 3.3V power supply for AGP clock output.
11 VDDZ PWR 3.3V power supply for HyperZip clock output.
1 VDDR PWR 3.3V power supply for REF clock output.
13,19 VDDP PWR 3.3V power supply for PCI clock output.
42 VDDC PWR 3.3V power supply for CPU clock output.
28 VDD48M PWR 3.3V power supply for 48-MHz/24-MHz clock output.
36 VDDA PWR 3.3V analog power supply.
18,24 VSSP PWR GND for PCI clocks outputs.
41 VSSC PWR GND for CPU clocks outputs.
8 VSSZ PWR GND for HyperZip clocks outputs.
25 VSS48M PWR GND for 48-MHz/24-MHz clocks outputs.
5 VSSR PWR GND for REF clocks outputs.
46 VSSSD PWR GND for SDRAM clocks outputs.
32 VSSAGP PWR GND for AGP clocks outputs.
37 VSSA PWR GND for analog.
Pin Description (continued)[2]
Pin Name PWR I/O Description
CY28342
Rev 1.0, November 20, 2006 Page 5 of 21
Table 2. Command Code Definition
Bit Description
7 0 = Block Read or block Write operation
1 = Byte Read or byte Write operation
(6:0) Byte offset for byte Read or byte Write operations. For block Read or block Write operations, these bits
should be “0000000”
Table 3. Block Read and Block Write Protocol
Block Write Protocol Block Read Protocol
Bit Description Bit Description
1Start 1Start
2:8 Slave address – 7 bits 2:8 Slave address – 7 bits
9Write 9Write
10 Acknowledge from slave 10 Acknowledge from slave
11:18 Command code – 8-bit “00000000” stands for
block operation 11:18 Command code – 8-bit “00000000” stands for
block operation
19 Acknowledge from slave 19 Acknowledge from slave
20:27 Byte count –8 bits 20 Repeat start
28 Acknowledge from slave 21:27 Slave address – 7 bits
29:36 Data byte 0 – 8 bits 28 Read
37 Acknowledge from slave 29 Acknowledge from slave
38:45 Data byte 1 – 8 bits 30:37 Byte count from slave – 8 bits
46 Acknowledge from slave 38 Acknowledge
.... Data byte N/slave acknowledge... 39:46 Data byte from slave – 8 bits
.... Data byte N – 8 bits 47 Acknowledge
.... Acknowledge from slave 48:55 Data byte from slave – 8 bits
.... Stop 56 Acknowledge
.... Data bytes from slave/acknowledge
.... Data byte N from slave – 8 bits
.... Not acknowledge
.... Stop
Table 4. Byte Read and Byte Write Protocol
Byte Write Protocol Byte Read Protocol
Bit Description Bit Description
1 Start 1 Start
2:8 Slave address – 7 bits 2:8 Slave address – 7 bits
9 Write 9 Write
10 Acknowledge from slave 10 Acknowledge from slave
11:18
Command Code – 8 bit “1xxxxxxx” stands for
byte operation bit[6:0] of the command code
represents the offset of the byte to be accessed
11:18
Command Code – 8-bit “1xxxxxxx” stands for
byte operation bit[6:0] of the command code
represents the offset of the byte to be accessed
19 Acknowledge from slave 19 Acknowledge from slave
20:27 Byte count – 8 bits 20 Repeat start
28 Acknowledge from slave 21:27 Slave address – 7 bits
29 Stop 28 Read
29 Acknowledge from slave
CY28342
Rev 1.0, November 20, 2006 Page 6 of 21
Since SDR and DDR Zero Delay Buffers will share this same address, the device starts from Byte 4.
30:37 Data byte from slave – 8 bits
38 Not acknowledge
39 Stop
Byte 4: CPU Clock Register (All bits are Read and Write functional)
Bit @Pup Pin# Name Description
7 H/W Setting 14 FS3 For selecting frequencies in Table 1.
6 H/W Setting 4 FS2 For selecting frequencies in Table 1.
5 H/W Setting 3 FS1 For selecting frequencies in Table 1.
4 H/W Setting 2 FS0 For selecting frequencies in Table 1.
3 0 0 = HW, 1 = SW frequency selection.
2 H/W Setting 15 FS4 For selecting frequencies in Table 1.
1 1 SSCG Spread Spectrum Enable. 0 = spread off, 1 = spread on.
This is a Read and Write control bit.
0 0 Master output control 0 = running, 1 = three-state all outputs.
Table 4. Byte Read and Byte Write Protocol (continued)
Byte Write Protocol Byte Read Protocol
Bit Description Bit Description
Byte 5: CPU Clock Register (all bits are Read-only)
Bit @Pup Pin# Name Description
70 Reserved.
60 Reserved.
5 X 26 MULT0 MULT0 (pin 26) value. This bit is Read-only.
4 X 15 FS4 FS4 Read-back. This bit is Read-only.
3 X 14 FS3 FS3 Read-back. This bit is Read-only.
2 X 4 FS2 FS2 Read-back. This bit is Read-only.
1 X 3 FS1 FS1 Read-back. This bit is Read-only.
0 X 2 FS0 FS0 Read-back. This bit is Read-only.
Byte 6: CPU Clock Register (All bits are Read and Write functional)
Bit @Pup Pin# Name Description
7 0 Function Test Bit. Always program to 0.
6 0 Reserved.
5 0 14 PCI_F0 PCI_STP# control of PCI_F0. 0 = free running, 1 = stopped when PCI_STP# is LOW.
4 0 15 PCI_F1 PCI_STP# control of PCI_F1. 0 = free running, 1 = stopped when PCI_STP# is LOW.
3 1 40,39 CPU0T/C
Controls CPU0T and CPU0C functionality when CPU_STP# is asserted LOW.
0 = free running, 1 = stopped with CPU_STP# asserted LOW.
This is a Read and Write control bit.
2044,43CPU1T/C
Controls CPU1T and CPU1C functionality when CPU_STP# is asserted LOW
0= Free Running, 1 Stopped with CPU_STP# asserted to LOW.
This and Read and Write control bit.
1 1 40,39 CPU0T/C CPU0T, CPU0C output control, 1= enabled, 0 = disabled.
This is a Read and Write control bit.
0144,43CPU1T/C
CPU1T, CPU1C output control, 1= enabled, 0 = disabled.
This is a Read and Write control bit.
CY28342
Rev 1.0, November 20, 2006 Page 7 of 21
Byte 7: PCI Clock Register (All bits are Read and Write functional)
Bit @Pup Pin# Name Description
7 1 15 PCI_F0 PCI_F0 output control 1 = enabled, 0 = forced LOW.
6 1 14 PCI_F1 PCI_F1 output control 1 = enabled, 0 = forced LOW.
5 1 23 PCI5 PCI5 output control 1 = enabled, 0 = forced LOW.
4 1 22 PCI4 PCI4 output control 1 = enabled, 0 = forced LOW.
3 1 21 PCI3 PCI3 output control 1 = enabled, 0 = forced LOW.
2 1 20 PCI2 PCI2 output control 1 = enabled, 0 = forced LOW.
1 1 17 PCI1 PCI1 output control 1 = enabled, 0 = forced LOW.
0 1 16 PCI0 PCI0 output control 1 = enabled, 0 = forced LOW.
Byte 8: Silicon Signature Register (all bits are Read-only)
Bit @Pup Description
7 1 Vendor ID
1000 = Cypress
60
50
40
3 0 Revision ID
20
10
00
Byte 9: Peripheral Control Register (All bits are Read and Write)
Bit @Pup Pin# Name Description
71 33 PD#PD# Enable. 0 = enable, 1 = disable.
60 0 = when PD# asserted LOW, CPU(0:1)T stop in a high state, CPU(0:1)C stop in
a LOW state. 1 = when PD# asserted LOW, CPU(0:1)T and CPU(0:1)C stop in H-Z.
5 1 27 48M 48M output control 1 = enabled, 0 = forced LOW.
4 1 26 48M_24M 48M_24M output control 1 = enabled, 0 = forced LOW.
3 0 26 48M_24M 48M_24M, 0 = pin 26 output is 24MHz, 1= pin 28 output is 48 MHz.
2 0 SS2 Spread Spectrum control bit (0= down spread, 1= center spread).
1 0 SS1 Spread Spectrum control bit. See Table 10.
0 0 SS0 Spread Spectrum control bit. See Table 10.
Byte 10: Peripheral Control Register (All bits are Read and Write functional)
Bit @Pup Pin# Name Description
7 1 47 SDCLK SDCLK output enable 1 = enabled, 0 = disabled.
6 1 4 REF2 REF2 output control 1 = enabled, 0 = forced LOW.
5 1 3 REF1 REF1 output control 1 = enabled, 0 = forced LOW.
4 1 2 REF0 REF0 output control 1 = enabled, 0 = forced LOW.
3 1 10 ZCLK1 ZCLK1 output enable 1 = enabled, 0 = disabled.
2 1 9 ZCLK0 ZCLK0 output enabled 1 = enabled, 0 = disabled.
1 1 30 AGP1 AGP1 output enabled 1 = enabled, 0 = disabled.
0 1 31 AGP0 AGP0 output enabled 1 = enabled, 0 = disabled.
CY28342
Rev 1.0, November 20, 2006 Page 8 of 21
Byte 11: Dial-a-Skew™ and Dial-a-Ratio™ Control Register (All bits are Read and Write functional)
Bit @Pup Name Description
7 0 DARSD2 Programming these bits allows modifying the frequency ratio of the SDCLK clock relative to the VCO.
See Table 5.
6 0 DARSD1
5 0 DARSD0
4 0 DARAG2 Programming these bits allows modifying the frequency ratio of the AGP(1:0), PCI(5:0) and PCIF(0:1)
clocks relative to the VCO. See Table 6.
3 0 DARAG1
2 0 DARAG0
1 0 DASSD1 Programming these bits allows shifting skew between CPU and SDCLK signals. See Ta ble 7.
0 0 DASSD0
Table 5. Dial-a-Ratio SDCLK
DARSD (2:0) VC0/SDCLK ratio
000 Frequency selection default
001 2
010 3
011 4
100 5
101 6
110 8
111 9
Table 6. Dial-a-Ratio AGP(0:1)[3]
DARAG (2:0) VC0/AGP Ratio
000 Frequency selection default
001 6
010 7
011 8
100 9
101 10
110 10
111 10
Table 7. Dial-a-Skew SDCLK CPU
DASSD (1:0) SDCLK-CPU Skew
00 0 ps (default)[4]
01 +150 ps (CPU lag)*
10 +300 ps (CPU lag)*
11 +450 ps (CPU lag)*
Notes:
3. The ratio of AGP to PCI is retained at 2:1.
4. See Figure 8 for CPU measurement point. See Figure 9 for SDCLK measurement point.
CY28342
Rev 1.0, November 20, 2006 Page 9 of 21
Byte 12: Watchdog Time Stamp Register (All bits are Read and Write functional)
Bit @Pup Name Description
71 SRESET#/PCI_STP#. 1 = pin 12 is the input pin as PCI_STP# signal. 0 = pin 12 is the output pin
as SRESET# signal.
60
Frequency Revert. This bit allows setting the Revert Frequency once the system is rebooted due
to Watchdog time-out only. 0 = selects frequency of existing H/W setting. 1 = selects frequency of
the second to last S/W setting (the software setting prior to the one that caused a system reboot).
50 WDTEST. For WD-Test, ALWAYS program to “0.”
40 WD Alarm. This bit is set to “1” when the Watchdog times out. It is reset to “0” when the system
clears the WD time stamps (WD3:0).
3 0 WD3 These bits select the Watchdog Time Stamp Value. See Table 8.
20WD2
10WD1
00WD0
Table 8. Watchdog Time Stamp Table
WD(3:0) FUNCTION
0000 Off
0001 1 second
0010 2 seconds
0011 3 seconds
0100 4 seconds
0101 5 seconds
0110 6 seconds
0111 7 seconds
1000 8 seconds
1001 9 seconds
1010 10 seconds
1011 11 seconds
1100 12 seconds
1101 13 seconds
1110 14 seconds
1111 15 seconds
Byte 13: Dial-a-Frequency Control Register N (All bits are Read and Write functional)[5]
Bit @Pup Description
7 0 Reserved.
60N6, MSB
50N5
40N4
30N3
20N2
10N3
00N0, LSB
Note:
5. Byte 13 and Byte 14 should be Write together in every case.
CY28342
Rev 1.0, November 20, 2006 Page 10 of 21
Dial-a-Frequency Feature
SMBus Dial-a-Frequency feature is available in this device via
byte 13 and byte 14. P is a large-value, phase-locked loop
(PLL) constant that depends on the frequency selection
achieved through the hardware selectors FS(4:0). P value
may be determined from the following table.
Spread Spectrum Clock Generation (SSCG)
Spread Spectrum is a modulation technique used to minimize
electromagnetic interference (EMI) radiation generated by
repetitive digital signals. A clock presents the greatest EMI
energy at the center of the frequency it is generating. Spread
Spectrum distributes this energy over a specific and controlled
frequency bandwidth, thereby causing the average energy at
any one point in this band to decrease in value. This technique
is achieved by modulating the clock away from its resting
frequency by a certain percentage (which also determines the
amount of EMI reduction). In this device, Spread Spectrum is
enabled by setting specific register bits in the SMBus control
bytes. See the SMBus register section of this data sheet for
the exact bit and byte functionally. The following table is a
listing of the modes and percentages of Spread Spectrum
modulation that this device incorporates.
Byte 14: Dial-a-Frequency Control Register (All bits are Read and Write functional)[5]
Bit @Pup Description
7 0 Reserved.
60R5 MSB
50R4
40R3
30R2
20R1
10R0, LSB
00R and N Register Load Gate. 0 = gate closed (data is latched), 1= gate open (data is loading
from SMBus registers into R and N)#.
Table 9.
FS(4:0) P
00000, 00001, 00010, 00111, 01001, 01011,
01110, 01111, 10010, 10100, 10110
95996900
00100, 00101, 10000, 10001, 10101, 10111,
11000, 11010, 11100, 11101, 11110, 11111
76797520
00110, 01000, 01010, 01100, 01101, 11001,
11011
63997933
00011, 10011 127995867 Table 10.Spread Spectrum
SS2 SS1 SS0 Spread Mode Spread%
0 0 0 Down 0, –0.50
0 0 1 Down +0.12, –0.62
0 1 0 Down +0.25, –0.75
0 1 1 Down +0.50, –1.00
1 0 0 Center +0.25, –0.25
1 0 1 Center +0.37, –0.37
1 1 0 Center +0.50, –0.50
1 1 1 Center +0.75, –0.75
CY28342
Rev 1.0, November 20, 2006 Page 11 of 21
System Self-recovery Clock Management
This feature is designed to allow the system designer to
change frequency while the system is running and reboot the
operation of the system in case of a hang up due to the
frequency change.
When the system sends an SMBus command requesting
a frequency change through byte 4 or through bytes 13 and
14, it must have previously sent a command selecting which
time-out stamp the Watchdog must perform to byte 12, or the
system self-recovery feature will not be applicable. Conse-
quently this device will change frequency, and then the
Watchdog timer starts timing. Meanwhile, the system BIOS is
running its operation with the new frequency. If this device
receives a new SMBus command to clear the bits originally
programmed in byte 12, bits(3:0) (reprogram to 0000) before
Watchdog times out, this device will keep operating in its
normal condition with the new selected frequency. If the
Watchdog times out the first time before the new SMBus repro-
grams byte 12, bits(3:0) to (0000), then this device will send
a low system reset pulse, on SRESET# (see byte 12, bit 7),
and changes the Watchdog alarm (byte 12, bit 4) status to “1”
then restarts the Watchdog timer. If the Watchdog times out
a second time, this device will send another low pulse on
SRESET#, will relatch original hardware strapping frequency
(or second-to-last software-selected frequency, see byte 12,
bit6) selection, set Watchdog alarm bit (byte 12, bit4) to “1,”
then start the Watchdog timer again. The above-described
sequence will keep repeating until the BIOS clears the SMBus
byte 12 bits(3:0). Once the BIOS sets byte 12 bits(3:0) = 0000,
the Watchdog timer is turned off and the Watchdog alarm bit
(byte 12, bit 4) is reset to “0.”
System running with
o rig in a lly s e le c te d
frequency via
hardware strapping.
Receive Frequency
Change Request via
SM B us Byte 4 or Via Dial-
a-frequency?
Start internal watch dog tim er.
W atch D og tim e out?
Turn off watch dog tim er.
Keep new frequency setting. Set W D alarm
bit (byte 12, bit4) to ''0'
1) Send another 3m S low pulse on SRES ET
2) Relatch original hardware strapping selection
for return to original frequency settings.
3) Set W D Alarm bit (byte 12, Bit4) to "1"
4 ) S ta rt W D tim e r
Frequency will change but System Self
Recovery not applicable (no tim e stam p
selected and byte 12, bit(3:0) is still =
"0000"
No
No
Yes
No
No
Yes
SM B us byte 12 tim e
out stam p disabled?
Is SMBus Byte 9, tim e out
stam p enabled - (byte 12, bit
(3:0) 0000)?
Change to a new
frequency
Yes
1) Send SRES ET
pulse
2) Set W D bit
(byte12, bit4) to '1'
3) Start W D tim er
Yes
W atch D og tim e out?
No
Yes
SMBus byte 9 tim e out
stam p disabled, Byte
12, bit(3:0) = (0000)?
Yes
No
Table 11.CPU Clock Current Select Function
Mult0 Board Target Trace/Term Z Reference R, Iref – VDD (3*Rr) Output Current Voh @ Z
0 50 Ohms (not used) Rr = 221 1%, Iref = 5.00mA IOH = 4*Iref 1.0V @ 50
1 50 Ohms Rr = 475 1%, Iref = 2.32mA IOH = 6*Iref 0.7V @ 50
Table 12.Group Timing Relationship and Tolerances
Offset Tolerance(or Range) Conditions Notes
CPU to SDCLK Typical 0 ns ±2 ns CPU leads Note 6
CPU to AGP Typical 2 ns 1-4ns CPU leads Note 6
CPU to ZCLK Typical 2 ns 1-4ns CPU leads Note 6
CPU to PCI Typical 2 ns 1-4ns CPU leads Note 6
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Rev 1.0, November 20, 2006 Page 12 of 21
Note:
6. See Figure 8 for CPU clock-measurement point. See Figure 9 for SDCLK, AGP, ZCLK and PCI output-measurement points.
Table 12.Group Timing Relationship and Tolerances
CY28342
Rev 1.0, November 20, 2006 Page 13 of 21
CPU_STP# Clarification
The CPU_STP# signal is an active LOW input used for
synchronous stopping and starting of the CPU output clocks
while the rest of the clock generator continues to function.
CPU_STP# Assertion
When CPU_STP# pin is asserted, all CPU outputs that are set
with the SMBus configuration to be stoppable via assertion of
CPU_STP# will be stopped after being sampled by two falling
CPU clock edges. The final state of the stopped CPU signals
is CPU = HIGH and CPU0# = LOW. There is no change to the
output drive current values during the stopped state. The CPU
is driven HIGH with a current value equal to (Mult0
“select”) × (Iref), and the CPU# signal will not be driven. Due
to external pull-down circuitry, CPU# will be LOW during this
stopped state.
CPU_STP# Deassertion
The deassertion of the CPU_STP# signal will cause all CPU
outputs that were stopped to resume normal operation in a
synchronous manner. Synchronous manner meaning that no
short or stretched clock pulses will be produce when the clock
resumes. The maximum latency from the deassertion to active
outputs is no more than two CPU clock cycles.
CPU_STP#
CPUT
CPUC
Figure 1. Assertion CPU_STP# Waveform
CPU_STP#
CPUT
CPUC
CPUT
CPUC
Figure 2. Deassertion CPU_STP# Waveform
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Rev 1.0, November 20, 2006 Page 14 of 21
PCI_STP# Assertion
The PCI_STP# signal is an active LOW input used for
synchronous stopping and starting the PCI outputs while the
rest of the clock generator continues to function. The set-up
time for capturing PCI_STP# going LOW is 10 ns (tsetup). (See
Figure 3.) The PCI_F (0:2) clocks will not be affected by this
pin if their control bits in the SMBus register are set to allow
them to be free running.
PCI_STP# Deassertion
The deassertion of the PCI_STP# signal will cause all PCI(0:6)
and stoppable PCI_F(0:2) clocks to resume running in
a synchronous manner within two PCI clock periods after
PCI_STP# transitions to a high level.
Note:
7. The PCI STOP function is controlled by 2 inputs. One is the device PCI_STP# pin number 34 and the other is SMBus byte 0 bit 3. These 2 inputs are logically
ANDed. If either the external pin or the internal SMBus register bit is set low then the stoppable PCI clocks will be stopped in a logic low state. Reading SMBus
Byte 0 Bit 3 will return a 0 value if either of these control bits are set LOW thereby indicating the device’s stoppable PCI clocks are not running.
PCI_STP#
PCI_F(0:2) 33M
PCI(0:6) 33M
setup
t
Figure 3. Assertion PCI_STP# Waveform
PCI_STP#
PCI_F(0:2)
PCI(0:6)
setup
t
Figure 4. Deassertion PCI_STP# Waveform[7]
CY28342
Rev 1.0, November 20, 2006 Page 15 of 21
PD# (Power-Down) Clarification
The PD# (power-down) pin is used to shut off ALL clocks prior
to shutting off power to the device. PD# is an asynchronous
active LOW input. This signal is synchronized internally to the
device powering down the clock synthesizer. PD# is an
asynchronous function for powering up the system. When PD#
is low, all clocks are driven to a LOW value and held there and
the VCO and PLLs are also powered down. All clocks are shut
down in a synchronous manner so has not to cause glitches
while transitioning to the low “stopped” state.
PD# - Assertion (transition from logic “l” to logic “0”)
When PD# is sampled LOW by two consecutive rising edges
of CPUC clock then all clock outputs (except CPUT) clocks
must be held LOW on their next HIGH-to-LOW transition.
CPUT clocks must be hold with CPUT clock pin driven HIGH
with a value of 2x Iref and CPUC undriven.
Due to the state of the internal logic, stopping and holding the
REF clock outputs in the LOW state may require more than
one clock cycle to complete.
PD# Deassertion (transition from logic “0” to logic “1”)
The power-up latency between PD# rising to a valid logic “1”
level and the starting of all clocks is less than 3.0 ms.
Note:
8. Device is not affected; VTTPWRGD is ignored.
PD#
CPU(0:1)T
CPU(0:1)C
CPU Internal
CPU# Internal
Figure 5. Power-down Assertion/Deassertion Timing Waveforms – Nonbuffered Mode
VID (0:3),
SEL (0,1)
VTTPWRGD
PWRGD
VDD Clock Gen
Clock State
Clock Outputs
Clock VCO
0.2-0.3mS
Delay
State 0 State 2 State 3
Wait for
VTT_GD# Sample Sels
Off
Off
On
On
State 1
(Note A)
Figure 6. VTTPWRGD Timing Diagram[8]
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Rev 1.0, November 20, 2006 Page 16 of 21
VTTPWRGD
=High
Delay 0.25mS
S1
Power Off
S0
VDDA = 2.0V
Sample
Inputs
FS(3:0)
S2
VDD3.3 = Off Normal
Operation
S3
Wait for
1.146ms Enable
Outputes
Outputs
Figure 7. Clock Generator Power-up/Run State Diagram
CY28342
Rev 1.0, November 20, 2006 Page 17 of 21
Maximum Ratings
Input Voltage Relative to VSS................................VSS – 0.3V
Input Voltage Relative to VDDQ or AVDD: ............. VDD + 0.3V
Storage Temperature:..................................–65qC to +150qC
Operating Temperature: ....................................0qC to +70qC
Maximum Power Supply: ............................................... 3.5V
DC Characteristics
Current Accuracy[9]
Conditions Configuration Load Min. Max.
Iout VDD = nominal (3.30V) M0= 0 or 1 and Rr shown in table Nominal test
load for given
configuration
–7% Inom +7% Inom
Iout VDD = 3.30 ±5% All combinations of M0 or 1 and Rr
shown in table
Nominal test
load for given
configuration
–12% Inom +12% Inom
DC Component Parameters (VDD =3.3V±5%, TA = 0°C to 70°C)
Parameter Description Min. Typ. Max. Units Conditions
Idd3.3V Dynamic Supply Current 280 mA All frequencies at maximum values[10]
Ipd3.3V Power-down Supply Current Note 11 mA PD# Asserted
Cin Input Pin Capacitance 5 pF
Cout Output Pin Capacitance 6 pF
Lpin Pin Inductance 7 nH
Cxtal Crystal Pin Capacitance 30 36 42 pF Measured from the XIN or XOUT Pin to
Ground
AC Parameters
Parameter Description
100 MHz 133 MHz
Unit NotesMin. Max. Min. Max.
Crystal
TDC XIN Duty Cycle 47.5 52.5 47.5 52.5 % 12,13
TPeriod XIN period 69.841 71.0 69.841 71.0 ns 12,13,14,15
VHIGH XIN HIGH Voltage 0.7VDD VDD 0.7VDD VDD V
VLOW XIN LOW Voltage 0 0.3VDD 00.3V
DD V
Tr/Tf XIN Rise and Fall Times 10.0 10.0 ns
TCCJ XIN Cycle to Cycle Jitter 500 500 ps 13,14,16
CPU at 0.7V Timing
TSKEW Any CPU to CPU Clock Skew 150 150 ps 16, 17, 18
TCCJ CPU Cycle to Cycle Jitter 150 150 ps 16, 17, 18
TDC CPU and CPUC Duty Cycle 45 55 45 55 % 16, 17, 18
TPeriod CPU and CPUC Period 9.8 10.2 7.35 7.65 ns 16, 17, 18
Notes:
9. Inom refers to the expected current based on the configuration of the device.
10. All outputs loaded as per maximum capacitive load table.
11. Absolute value = (programmed CPU Iref 97) +10 mA.
12. This parameter is measured as an average over 1Ps duration with a crystal center frequency of 14.318 MHz.
13. When XIN is driven from an external clock source.
14. All outputs loaded per Table 13 below.
15. Probes are placed on pins and measurements are acquired at 1.5V for 3.3V signals (see test and measurement set-up section).
16. This measurement is applicable with Spread ON or Spread OFF.
17. Measured at crossing point (Vx), or where subtraction of CLK–CLK# crosses 0V.
18. For CPU load. See Figure 8.
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Rev 1.0, November 20, 2006 Page 18 of 21
Tr/Tf CPU and CPUC Rise and Fall Times 175 700 175 700 ps 16,19
Rise/Fall Matching 20% 20% 18,19,20
DeltaTr Rise Time Variation 125 125 ps 18,19
DeltaTf Fall Time Variation 125 125 ps 18,19
Vcross Crossing Point Voltage at 0.7V Swing 280 430 280 430 mV 17,18,19
AGP
TDC AGP Duty Cycle 45554555 % 14, 15
TPeriod AGP Period 15.0 15.3 15.0 15.3 ns 14, 15
THIGH AGP HIGH Time 5.25 5.25 ns 21
TLOW AGP LOW Time 5.05 5.05 ns 22
Tr/Tf AGP Rise and Fall Times 0.5 1.6 0.5 1.6 ns 14, 23
Tskew
Unbuffered
Any AGP to Any AGP Clock Skew 175 175 ps 14, 15
TCCJ AGP Cycle-to-Cycle Jitter 250 250 ps 14, 15
ZCLK
TDC ZCLK(0:1) Duty Cycle 45 55 45 55 % 14, 15
Tr/Tf ZCLK(0:1) Rise and Fall Times 0.5 1.6 0.5 1.6 ns 14, 23
TSKEW Any ZCLK(0:1) to Any ZCLK(0:1) Skew 175 175 ps 14, 15
TCCJ ZCLK(0:1) Cycle-to-Cycle Jitter 250 250 ps 14,15
PCI
TDC PCI_F(0:1) PCI (0:5) Duty Cycle 45 55 45 55 % 14, 15
TPeriod PCI_F(0:1) PCI (0:5) Period 30.0 30.0 nS 12,14,15
THIGH PCI_F(0:1) PCI (0:5) HIGH Time 12.0 12.0 nS 21
TLOW PCI_F(0:1) PCI (0:5) LOW Time 12.0 12.0 nS 22
Tr/Tf PCI_F(0:1) PCI (0:5) Rise and Fall times 0.5 2.0 0.5 2.0 nS 14, 23
TSKEW Any PCI Clock to Any PCI Clock Skew 500 500 ps 14, 15
TCCJ PCI_F(0:1) PCI (0:5) Cycle-to-Cycle Jitter 250 250 ps 14, 15
SDCLK
TDC SDCLK Duty Cycle 45 55 45 55 % 14, 15
TPeriod SDCLK Period 9.8 10.2 7.35 7.65 ns 14, 15
THIGH SDCLK HIGH Time 3.0 1.87 ns 21
TLOW SDCLK LOW Time 2.8 1.67 ns 22
Tr/Tf SDCLK Rise and Fall Times 0.4 1.6 0.4 1.6 ns 14, 23
TCCJ SDCLK Cycle-to-Cycle Jitter 250 250 ps 14, 23
48M
TDC 48M Duty Cycle 45 55 45 55 % 14, 15
TPeriod 48M Period 20.829 20.834 20.829 20.834 ns 14, 15
Tr/Tf 48M Rise and Fall Times 1.0 2.0 1.0 2.0 ns 14, 23
TCCJ 48M Cycle-to-Cycle Jitter 350 350 ps 14, 15
Notes:
19. Measured from VOL = 0.175 to VOH = 0.525V.
20. Determined as a fraction of 2*(Trise–Tfall)/(Trise+Tfall).
21. THIGH is measured at 2.4V for all non-host outputs.
22. TLOW is measured at 0.4V for all non-host outputs.
23. Probes are placed on pins and measurements are acquired between 0.4V and 2.4V for 3.3V signals (see test and measurement set-up section).
AC Parameters (continued)
Parameter Description
100 MHz 133 MHz
Unit NotesMin. Max. Min. Max.
CY28342
Rev 1.0, November 20, 2006 Page 19 of 21
24M
TDC 24-MHz Duty Cycle 45554555 % 14, 15
TPeriod 24-MHz Period 41.66 41.67 41.66 41.67 ns 14, 15
Tr/Tf 24-MHz Rise and Fall Times 1.0 4.0 1.0 4.0 ns 14, 23
TCCJ 24-MHz Cycle-to-Cycle Jitter 500 500 ps 14, 15
REF
TDC REF Duty Cycle 45554555 % 14, 15
TPeriod REF Period 69.8413 71.0 69.8413 71.0 ns 14, 15
Tr/Tf REF Rise and Fall Times 1.0 4.0 1.0 4.0 ns 14, 23
TCCJ REF Cycle-to-Cycle Jitter 1000 1000 ps 14, 15
ENABLE/DISABLE and SET UP
tpZL, tpZH Output Enable Delay (All Outputs) 1.0 10.0 1.0 10.0 ns
tpLZ, tpZH Output Disable Delay (All Outputs) 1.0 10.0 1.0 10.0 ns
tstable All Clock Stabilization from Power-up 1.5 1.5 ms
tss Stopclock Set-up Time 10.0 10.0 ns
tsh Stopclock Hold Time 0 0 ns 24
AC Parameters (continued)
Parameter Description
100 MHz 133 MHz
Unit NotesMin. Max. Min. Max.
Table 13.Maximum Lumped Capacitive Output Loads
Clock Max. Load Units
PCI(0:5), PCI_F(0:1) 30 pF
AGP (0:1), SDCLK 30 pF
ZCLK (0:1) 30 pF
48M_24, 48M Clock 20 pF
REF (0:2) 30 pF
CPU(0:1)T
CPU(0:1) C
2pF
Notes:
24. CPU_STP# and PCI_STP# set-up time with respect to any PCI_F clock to guarantee that the affected clock will stop or start at the next PCI_F clock’s rising edge.
25. When crystal meets minimum 40 ohm device series resistance specification.
26. This is required for the duty cycle on the REF clock out to be as specified. The device will operate reliably with input duty cycles up to 30/70, but the REF clock
duty cycle will not be within data sheet specifications.
CY28342
Rev 1.0, November 20, 2006 Page 20 of 21
Test and Measurement Set-up
For Differential CPU Output Signals
The following diagram shows lumped test load configurations
for the differential Host Clock Outputs.
CPUT
MULTSEL
TPCB
TPCB
CPUC
33:
33:
49.9:
49.9:
Measurement Point
2 pF
475:
IREF
Measurement Point
2 pF
Figure 8. 0.7V Configuration
2.4V
0.4V
3.3V
0V
Tr Tf
1.5V
3.3V signals
tD C
Probe
Output under Test
Load Cap
--
Figure 9. Lumped Load For Single-Ended Output Signals (for AC Parameters Measurement)
Ordering Information
Part Number Package Type Product Flow
CY28342OC 48-pin Shrunk Small Outline Package (SSOP) Commercial 0q to 70qC
CY28342OCT 48-pin Shrunk Small Outline Package (SSOP) – Tape and Reel Commercial 0q to 70qC
CY28342ZC 48-pin Thin Shrunk Small Outline Package (TSSOP) Commercial 0q to 70qC
CY28342ZCT 48-pin Thin Shrunk Small Outline Package (TSSOP) – Tape and Reel Commercial 0q to 70qC
Rev 1.0, November 20, 2006 Page 21 of 21
CY28342
While SLI has reviewed all information herein for accuracy and reliability, Spectra Linear Inc. assumes no responsibility for the use of any cir-
cuitry or for the infringement of any patents or other rights of third parties which would result from each use. This product is intended for use in
normal commercial applications and is not warranted nor is it intended for use in life support, critical medical instruments, or any other applica-
tion requiring extended temperature range, high reliability, or any other extraordinary environmental requirements unless pursuant to additional
processing by Spectra Linear Inc., and expressed written agreement by Spectra Linear Inc. Spectra Linear Inc. reserves the right to change any
circuitry or specification without notice.
Package Drawing and Dimensions
48-lead Shrunk Small Outline Package O48
48-lead Thin Shrunk Small Outline Package, Type II (6 mm x 12 mm) Z48
51 85059 *B