2

ICS951412

0883G—12/08/04

Pin Descriptions

PIN

#

PIN NAME

PIN

TYPE

DESCRIPTION

1

X1

IN

Crystal input, Nominally 14.318MHz.

2

X2

OUT

Crystal output, Nominally 14.318MHz

3

VDD48

PWR

Power pin for the 48MHz output.3.3V

4

USB_48MHz

OUT

48.00MHz USB clock

5

GND

PWR

Ground pin.

6

NC

N/A

No Connection.

7

SCLK

IN

Clock pin of SMBus circuitry, 5V tolerant.

8

SDATA

I/O

Data pin for SMBus circuitry, 5V tolerant.

9

**FS2

IN

Frequency select pin.

10

**CLKREQA#

IN

Output enable for PCI Express (SRC) outputs. SMBus selects which

outputs are controlled.

0 = enabled, 1 = tri-stated

11

**CLKREQB#

IN

Output enable for PCI Express (SRC) outputs. SMBus selects which

outputs are controlled.

0 = enabled, 1 = tri-stated

12

SRCCLKT7

OUT

True clock of differential SRC clock pair.

13

SRCCLKC7

OUT

Complement clock of differential SRC clock pair.

14

VDDSRC

PWR

Supply for SRC clocks, 3.3V nominal

15

GNDSRC

PWR

Ground pin for the SRC outputs

16

SRCCLKT6

OUT

True clock of differential SRC clock pair.

17

SRCCLKC6

OUT

Complement clock of differential SRC clock pair.

18

SRCCLKT5

OUT

True clock of differential SRC clock pair.

19

SRCCLKC5

OUT

Complement clock of differential SRC clock pair.

20

GNDSRC

PWR

Ground pin for the SRC outputs

21

VDDSRC

PWR

Supply for SRC clocks, 3.3V nominal

22

SRCCLKT4

OUT

True clock of differential SRC clock pair.

23

SRCCLKC4

OUT

Complement clock of differential SRC clock pair.

24

SRCCLKT3

OUT

True clock of differential SRC clock pair.

25

SRCCLKC3

OUT

Complement clock of differential SRC clock pair.

26

GNDSRC

PWR

Ground pin for the SRC outputs

27

ATIGCLKT1

OUT

True clock of differential SRC clock pair.

28

ATIGCLKC1

OUT

Complementary clock of differential SRC clock pair.