3

ICS950818

0825F—11/19/03

Pin Description (Continued)

Power Supply

PIN # PIN NAME

PIN TYPE

DESCRIPTION

25

SDATA

I/O

Data pin for I2C circuitry 5V tolerant

26

SCLK

IN

Clock pin of I2C circuitry 5V tolerant

27

GND

PWR

Ground pin.

28

VDD3V66

PWR

Power pin for the 3V66 clocks.

29

PCICLK10

OUT

PCI clock output.

30

PCI_STOP#

IN

Stops all PCICLKs besides the PCICLK_F clocks at logic 0 level, when input

low

31

3V66_1/VCH_CLK

OUT

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

32

GND

PWR

Ground pin.

33

VDD48

PWR

Power pin for the 48MHz output.3.3V

34

48MHz_DOT

OUT

48MHz clock output.

35

48MHz_USB

OUT

48MHz clock output.

36

FS0

IN

Frequency select pin.

37

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.

38

CPUCLKC1

OUT

Complimentary clock of differential pair CPU outputs. These are current

mode outputs. External resistors are required for voltage bias.

39

CPUCLKT1

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

GND

PWR

Ground pin.

42

CPUCLKC0

OUT

Complimentary clock of differential pair CPU outputs. These are current

mode outputs. External resistors are required for voltage bias.

43

CPUCLKT0

OUT

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

outputs. External resistors are required for voltage bias.

44

VDDCPU

PWR

Supply for CPU clocks, 3.3V nominal

45

CPU_STOP#

IN

Stops all CPUCLK besides the free running clocks

46

FS1

IN

Frequency select pin.

47

REF

OUT

14.318 MHz reference clock.

48

VDDREF

PWR

Ref, XTAL power supply, nominal 3.3V

VDD

GND

48

3

Xtal, Ref

11

7

PCICLK outputs

15, 28

16, 27

3V66

22

23

Master clock, CPU Analog

33

32

48MHz, Fix Digital, Fix Analog

41

Inputs

40, 44

41

CPUCLK clocks

Pin Number

Description