AMD Geode™ GX2 Clock Source

MDS 1491-09 G

2

Revision 080204

Integrated Circuit Systems, Inc.

MK1491-09

Pin Assignment

PCI Frequency Select Table

EMI Control

Spread direction is DOWN.

Pin Descriptions

KEY: I = Input, TI = Tri-level, O = Output, P = Power supply connection, (T)I/O = Input on power up,

becomes an Output after 10 ms, Weak internal pull-up resistors are present on TS#, Spread#, PD#, and

Sel66/33.

18

7

17

8

16

9

15

GND

10

VDD

11

LCLK2/33M

12

GND

13

Sel66/33#

14

GND

VDD

PCICLK0/33-66M

VDD

PD#

GND

48M

66M

22

21

20

19

48M/TS#

GND

5

6

LCLK0/33M

LCLK1/33M

24

23

3

4

XO

VDD

VDD

26

25

RefCLK1

1

2

GND

XI

RefCLK0/Spread#

28

27

VDD

PCICLK1/33-66M

PCICLK2/33-66M

PCICLK3/33-66M

Sel66/33#

PCI Frequency

033 MHz

166 MHz

Spread#

PCI Low EMI

0ON

1OFF

Pin

Number

Pin

Name

Pin

Type

Pin Description

1, 7, 11, 15, 21, 22

GND

P

Connect to Ground.

2

XI

I

Crystal connection. Connect to a 14.31818 MHz crystal or input clock.

3

XO

O

Crystal connection. Connect to a 14.31818 MHz crystal, or leave

unconnected.

4, 8, 12, 19, 25, 28

VDD

P

Connect to 3.3 V.

5, 6, 9

LCLK

O

33 MHz low skew clock outputs.

10

Sel66/33#

I

Selects frequency on PCICLK.

13

48M

O

48 MHz clock output.

14

48M/TS#

I/O

48 MHz clock output. TS# is high at power-up.

16

66M

O

66 MHz clock output.

17

PD#

I

Power-down input (see table on page 3).

18, 20, 23, 24

PCICLK

O

33 to 66 MHz PCI synchronous clock outputs with low skew.

26

RefCLK1

O

Buffered reference output of 14.31818 MHz.

27

RefCLK0/

Spread#

I/O

Buffered reference output of 14.31818 MHz. Spread select at

power-up. For Spread#, see table above.