3

Integrated

Circuit

Systems, Inc.

ICS952606

0717F—06/10/05

Pin Description (Continued)

PIN #

PIN NAME

PIN TYPE

DESCRIPTION

30

3V66_0

OUT

3.3V 66.66MHz clock output

25

3V66_3/VCH

OUT

3.3V 66.66MHz clock output / 48MHz VCH clock output.

26

3V66_2

OUT

3.3V 66.66MHz clock output

27

VDD3V66

PWR

Power pin for the 3.3V 66MHz clocks.

28

GND

PWR

Ground pin.

29

3V66_1

OUT

3.3V 66.66MHz clock output

30

3V66_0

OUT

3.3V 66.66MHz clock output

31

SCLK

IN

Clock pin of SMBus circuitry, 5V tolerant.

32

SDATA

I/O

Data pin for SMBus circuitry, 5V tolerant.

33

Vtt_Pwrgd#

IN

This 3.3V LVTTL input is a level sensitive strobe used to determine

when latch inputs are valid and are ready to be sampled. This is an

active low input.

34

VDD

PWR

Power supply, nominal 3.3V

35

SRCCLKC

OUT

Complement clock of differential pair for S-ATA support.

+/- 300ppm accuracy required.

36

SRCCLKT

OUT

True clock of differential pair for S-ATA support.

+/- 300ppm accuracy required.

37

GND

PWR

Ground pin.

38

CPUCLKC0

OUT

Complementary clock of differential pair CPU outputs. These are

current mode outputs. External resistors are required for voltage bias.

39

CPUCLKT0

OUT

True clock of differential pair CPU outputs. These are current mode

outputs. External resistors are required for voltage bias.

40

VDDCPU

PWR

Supply for CPU clocks, 3.3V nominal

41

CPUCLKC1

OUT

Complementary clock of differential pair CPU outputs. These are

current mode outputs. External resistors are required for voltage bias.

42

CPUCLKT1

OUT

True clock of differential pair CPU outputs. These are current mode

outputs. External resistors are required for voltage bias.

43

GND

PWR

Ground pin.

44

CPUCLKC_ITP

OUT

Complementary clock of differential pair CPU outputs. These are

current mode outputs. External resistors are required for voltage bias.

45

CPUCLKT_ITP

OUT

True clock of differential pair CPU outputs. These are current mode

outputs. External resistors are required for voltage bias.

46

IREF

OUT

This pin establishes the reference current for the differential current-

mode output pairs. This pin requires a fixed precision resistor tied to

ground in order to establish the appropriate current. 475 ohms is the

standard value.

47

GND

PWR

Ground pin.

48

VDDA

PWR

3.3V power for the PLL core.