CY28342OCT - Cypress Semiconductor

High-performance SiS645/650 Pentium  4 Clock Synthesizer

CY28342

Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600

Document #: 38-073 49 Rev. *A Revised July 29, 2002

Features

• Supports Pentium 4-type CPUs

• 3.3V power supply

• Eight copies of PCI clocks

• One 4-MHz USB clock

• Two copies of ZCLK clocks

• One 48-MHz/24-MHz 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-u p resistors. Pins marked wi th [**] have internal pull-down resistors.

Block Diagram Pin Configuration[1]

PLL1

PLL2

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

Latch

SDCLK

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

&<

48 Pin SSOP andf TSSOP

CY28342

Document #: 38-07349 Rev. *A Page 2 of 22

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

Document #: 38-07349 Rev. *A Page 3 of 22

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 o utput clo ck p a irs. See Table 1 for frequenci es 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 inp ut. Whe n

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 inp ut. Whe n

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 inp ut. Whe n

VTTPWRGD i s transited to l ogic LOW , FS1 st ate is latc hed and this p in

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 inp ut. Whe n

VTTPWRGD i s transited to l ogic LOW , FS2 st ate is latc hed and this p in

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

transitio n, this pin bec om es a PD # i npu t with an inte rnal pull-up . W hen

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 MUL T0 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 pul l-up is not activ e. See

system reset description.

PCI_STP# I

PU System Reset Control Output. If Byte12 Bit7 = 1 (Default), this pin

becomes PCI C l ock Dis ab le I npu t. Wh en PC I_STP# is as se rted 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.

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Document #: 38-07349 Rev. *A Page 4 of 22

Serial Data Interface

To enhanc e the flexibi lity and func tion of the c lock synth esizer ,

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 regis ters assoc iated with the SDI initializes to their defau lt

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 clo ck driv er serial pro tocol ac cepts byte W rite, by te Rea d,

block W rite, 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 de scribed in Table 2.

The bloc k W r ite and bloc k Read prot ocol is outli ned in Table 3

while Table 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 VDD 48M PWR 3.3V power supply for 48-MHz/24-MHz clock output.

36 VD DA PWR 3.3V ana log power supply.

18,24 VSSP PWR GND for PCI clocks output s.

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 GN D 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

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Document #: 38-07349 Rev. *A Page 5 of 22

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 of fse t for byte Read or byte W rite operati ons. Fo r block R ead or bl ock W rite operatio ns, the se bit s

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 bit s

29 Stop 28 Read

29 Acknowledge from slave

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Document #: 38-07349 Rev. *A Page 6 of 22

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.

60 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.

2 0 44,43 CPU1T/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.

0 1 44,43 CPU1T/C CPU1T, CPU1C output control, 1= enabled, 0 = disabled.

This is a Read and Write control bit.

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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 -onl y)

Bit @Pup Description

7 1 Vendor ID

1000 = Cypress

3 0 Revision ID

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# as serted LOW, CPU(0 :1)T s to p in a high state, CP U(0:1)C s to p 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 9.

0 0 SS0 Spread Spectrum control bit. See Table 9.

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.

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Document #: 38-07349 Rev. *A Page 8 of 22

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 bit s allows modifying the frequency ratio of th e 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 Table 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-Rat io 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 la g)*

10 +300 ps (CPU la g)*

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.

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Document #: 38-07349 Rev. *A Page 9 of 22

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 secon ds

1011 11 seconds

1100 12 secon ds

1101 13 secon ds

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

70Reserved.

60N6, MSB

50N5

40N4

30N3

20N2

10N3

00N0, LSB

Note:

5. Byte 13 and Byte 14 should be Write together in every case.

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Document #: 38-07349 Rev. *A Page 10 of 22

Dial-a-Fr equency Feature

SMBus Dial-a -Frequency fea ture is availabl e in this devic e 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 Sp ectrum is a m od ula tio n tec hni que used t o m in im ize

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

Spect rum distributes this ene rgy over a specific and contro lled

frequency bandwidth, thereby causing the average energy at

any one poi nt in this band to decrease in value. Thi s techniqu e

is achieved by modulating the clock away from its resting

frequenc y by a cert ain perce nt age (which a lso d etermi nes 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 an d N Re gister Lo ad Gat e. 0 = gate closed (dat a is latch ed), 1= gat e open (dat a is loadi ng

from SMBus registers into R and N)#.

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 9. Spread Spectrum

SS2 SS1 SS0 Spread Mode Spread%

000 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

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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 chan ges the Watc hdo g 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

sequenc e will keep repea ting until the BIOS c lears the SMBus

byte 12 b its(3:0). Onc e the BIOS set s byte 12 bit s(3:0) = 000 0,

the Watchdog timer is turned off and the Watchdog alarm bit

(byte 12, bit 4) is reset to “0.”

System running w ith

o rig in a lly s e le c te d

frequency via

h ardw a re strap pin g.

Receive Frequency

Change Request via

SMBus Byte 4 or Via Dial-

a-frequency?

S ta rt in tern al w a tch d og tim er.

W atch Dog tim e out?

Turn off watch dog tim er.

K e e p n e w fre qu e nc y s etting . S et W D a la rm

bit (byte 12, bit4) to ’’0’

1) Send another 3m S low pulse on SRESET

2 ) R e latc h o rig in a l h a rd w a re s tra p p in g s e le c tio n

fo r re tu rn to o rig ina l fre q u en c y s e tting s .

3 ) S e t W D A la rm bit (b yte 1 2, B it4 ) to "1 "

4 ) S ta rt W D tim er

Frequency will change but System Self

Recovery not applicable (no tim e stam p

selected and byte 12, bit(3:0) is still =

"0000"

Yes

SMBus byte 12 tim e

out stamp disabled?

Is S M B u s B yte 9 , tim e o u t

stam p enabled - (byte 12, bit

(3 :0) 0 00 0 )?

Change to a new

frequency

Yes

1) Send SRESET

pulse

2) Set W D bit

(byte12, bit4) to ’1’

3 ) S ta rt W D tim er

Yes

W a tch D o g tim e o ut?

Yes

SM B u s b yte 9 tim e o u t

stam p disabled, Byte

12, bit(3:0) = (0000)?

Yes

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Document #: 38-07349 Rev. *A Page 12 of 22

Table 10. 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 11. Group Timing Relationship and Tolerances

Offset Tolerance

(or Range) Condit ions 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

Note:

6. See Figure 8 for CPU clock- me asu rem en t poi nt. See Figure 9 for SDCLK, AGP, ZCLK and PCI output-measurement points.

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Document #: 38-07349 Rev. *A Page 13 of 22

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 C PU_STP# pin is as serted, all CPU output s that are s et

with the SMBus configuration to be stoppable via assertion of

CPU_S TP# wi ll be st opp ed after b ein g s am pl ed by two falling

CPU cl o ck e dge s. T he f i na l state of t he s t op pe d CPU si gn als

is CPU = HIGH a nd CPU0# = LOW. There is no change to th e

output drive cu rrent val ues duri ng the s topped s tate. The CPU

is driven HIGH with a current value equal to (Mult0

“select”)×(Iref), and the CPU# signal will not be driven. Due

to ext ernal pu ll-dow n circuit ry, CPU# will be LO W during th is

stopped state.

CPU_STP# Deassertion

The de asserti on of the C PU_STP# si gnal will cause all CPU

outputs that were stopped to resume normal operation in a

synchronous manner. Synchronous manner meaning that no

short or s tretche d clock puls es wi ll be produc e w hen th e cl ock

resumes. The maximum latency from the deassertio n 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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Document #: 38-07349 Rev. *A Page 14 of 22

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 i s 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# Deassertio n

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

Figure 3. Assertion PCI_STP# Waveform

PCI_STP#

PCI_F(0:2)

PCI(0:6)

setup

Figure 4. Deassertion PCI_STP# Waveform[7]

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Document #: 38-07349 Rev. *A Page 15 of 22

PD# (Power-Down) Clarification

The PD# (p ower-down) pin is used to s hut off ALL clocks prior

to shutting off power to the device. PD# is an asynchronous

active LOW input. Thi s signa l is synchron ized int ernally 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 t o a LOW v alue and held there and

the VCO and PL Ls are also powere d down. All clock s are shut

down in a synch ronous m anner so ha s not to cau se glit ches

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 t he s t a t e o f the int erna l l ogic, stopping and holding th e

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 G en

Clock State

Clock Outputs

Clock VCO

0.2-0.3mS

Delay

State 0 State 2 State 3

Wait for

VTT_GD# Sample Sels

Off

State 1

(Note A)

Figure 6. VTTPWRGD Timing Diagram[8]

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Document #: 38-07349 Rev. *A Page 16 of 22

VTTPWRGD

= High

Delay 0.25m S

Power O ff

VD D A = 2.0V

Sample

Inputs

FS(3:0)

VDD3.3 = Off Normal

Operation

Wait fo r

1.146ms Enable

Outputes

Outputs

Figure 7. Clock Generator Power-up/Run State Diagram

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Document #: 38-07349 Rev. *A Page 17 of 22

Maximum Ratings

Input Voltage Relative to VSS................................VSS – 0.3V

Input Voltage Relative to VDDQ or AVDD: .............VDD + 0.3V

Storage Tempe r atu re:................................. –65°C to +150°C

Operating Temperature: ................................... 0°C to +70°C

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 co mbina tions of M0 or 1 a nd 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 Dynam ic Supply Current 280 mA All frequencies at maximum values[10]

Ipd3.3V Power-down Supply Curr ent Not e 11 mA PD# Asserted

Cin Input Pin Capacitance 5 pF

Cout Output Pin Capacitance 6 pF

Lpin Pin I nductance 7 nH

Cxt al Crysta l Pin Capac itanc e 30 36 42 pF Measur ed from the XIN or X OUT Pin to

Ground

AC Parameters

Parameter Description 100 M Hz 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. Abs olute valu e = (program med CPU Iref 97) +10 mA.

12. This parameter is measured as an average over 1−µs duration wi th a crystal center fre que ncy of 14.3 18 MHz.

13. When XIN is driven fro m an exter na l clock source.

14. All outputs loaded per Table 12 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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Document #: 38-07349 Rev. *A Page 18 of 22

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 45 55 45 5 5 % 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 Cycl e 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-t o-Cy cle Jitte r 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 Ti me 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 % 1 4, 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 Peri od 20.829 20.834 20.829 20.83 4 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*(T rise–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 sectio n) .

AC Parameters (continued)

Parameter Description 100 M Hz 133 MHz Unit NotesMin. Max. Min. Max.

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Document #: 38-07349 Rev. *A Page 19 of 22

24M

TDC 24-MHz Duty Cycle 45 55 45 5 5 % 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 45 55 45 55 % 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 Ou tput 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 M Hz 133 MHz Unit NotesMin. Max. Min. Max.

Table 12. 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

Document #: 38-07349 Rev. *A Page 20 of 22

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

CPUC

33Ω

49.9Ω

M easurement Point

2 pF

475Ω

IREF

M easurement Point

2 pF

Figure 8. 0.7V Configuration

.4V

3.3V

Tr Tf

.5V

3.3V signals

tDC

Probe

O utput 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 0° to 70°C

CY28342OCT 48-pin Shrunk Small Outline Package (SSOP) – Tape and Reel Commercial 0° to 70°C

CY28342ZC 48-pin Thin Shrunk Small Outline Package (TSSOP) C ommercial 0° to 70°C

CY28342 ZCT 48-pin Thi n Shrunk Small Outli ne Package (TSSOP) – Tape and R eel Commercial 0° to 70°C

CY28342

Document #: 38-07349 Rev. *A Page 21 of 22

of any ci rcuitry other th an circuitry embod ied in a Cypr ess Semiconductor pr oduct. Nor does it convey or imply any licen se under p atent or other rights. Cy press Semiconductor does not autho rize

its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress

Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.

Package Drawing and Dimensions

Pentium is a registered trademark of Intel Corporation. Dial-a-Frequency and Dial-a-dB are registered trademarks and Dial-a-Ratio

and Dial-a-Skew are trademarks of Cypress Semiconductor Corporation. All product and company names mentioned in this

document may be the trademarks of their respective holders.

48-leadShrunk Small Outline Package O48

51-85061-*C

48-lead Thin Shrunk Small Outline Package, Type II (6 mm x 12 mm) Z48

51-85059-*B

CY28342

Document #: 38-07349 Rev. *A Page 22 of 22

Document History Page

Document Title: CY28342 High-performance SiS645/650 Pentium 4 Clock Synthesizer

Document Number: 38-07349

REV. ECN NO. Issue Date Orig. of

Change Description of Change

** 111854 03/04/02 DMG New Data Sheet

*A 117644 09/11/02 DMG Changed the VTTPWRGD transition logic from LOW to HIGH in page 3.

Changed the Power Up default in Byte 9 Bit 3 from 1 to 0 in page 7.