MK1491-06

MDS 1491-06 F

2

Revision 101700

Printed 11/15/00

Integrated Circuit Systems, Inc. • 525 Race Street • San Jose • CA • 95126 • (408)295-9800tel • www.icst.com

Pin #

Name

Type Description

1, 9, 14

VDD

P

Connect to +3.3V. Must be same voltage on all pins.

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 for clock.

4, 7, 11, 17, 23

GND

P

Connect to Ground.

5

14.3M(TS)

TI/O 14.318 MHz output. Input control for all clocks per table above.

6

14.3M

O

14.318 MHz buffered reference clock output.

8

14.3M(SEL AUDIO) TI/O 14.318 MHz output and audio frequency select input per table above.

10

SLOW#

I

PCI normal or slow mode select input per table on page 4.

12

FS

I

Frequency Select for PCI clocks per table above.

13

SEL24

I

Fixed frequency select input per table above. Selects frequency on pin 19.

15

PWRDWN#

I

Power down control; defined in table on page 4.

16

PCISTP#

I

PCI Stop power down control; defined in table on page 4.

18, 20, 26

VDD

P

Connect to +3.3V. Must be same voltage on all pins.

19

24M/14.3M

O

Fixed frequency clock output per table above.

21

48(LE#)

I/O

Fixed frequency clock output and low EMI (spread spectrum) enable input per table above.

22

PCI(EPCI#)

I/O

PCI Output clock that can be early. Input control for Early PCI per table above.

24

PCI

O

PCI Output clock. PCI/PCIF control set by PEN per table above.

25

PCI

O

PCI Output clock. PCI/PCIF control set by PEN per table above.

27

PCI

O

PCI Output clock.

28

AC97 AUDIO(PEN) TI/O Audio clock output and PCIF Function Enable per table above.

Pin Descriptions

PCI Frequency Select Table

Pin Assignment

1

8

9

2

3

4

5

6

7

10

11

12

13

14

16

15

20

17

18

19

25

24

23

22

21

26

27

28

VDD

GND

14.3M

XO

VDD

14.3M(TS)

SLOW#

14.3M(SEL AUDIO)

XI

GND

VDD

GND

SEL24

FS

24M/14.3M Frequency

Select Table

EPCI#

PCI (Pin 22)

0

1 ns early

1

Normal

Early PCI Control Table

SEL24

24M/14.3M

0

14.31818 MHz

1

24.0 MHz

EMI Control

LE#

PCI Low EMI

0

ON

1

OFF

Key: I = Input, TI = tri-level input, O = Output, P = Power supply connection, (T)I/O = Input on power up, becomes an Output after 10ms.

Weak internal pull-up resistors are present on SEL24, EPCI#, FS, LE#, PCISTP#, and SLOW#. These pins should be tied to VDD or GND,

and not be left floating. Internal resistors on PEN, SEL AUDIO, and TS pull to a mid-level (M).

SEL AUDIO

AC97 AUDIO

0

16.9344 MHz

M

24.576 MHz

1

49.152 MHz

AC97 Audio Frequency Select

VDD

PCI(EPCI#)

GND

VDD

AC97 AUDIO(PEN)

24M/14.3M

48M(LE#)

PCI

PCI

PWRDWN#

VDD

PCISTP#

GND

PCI

PEN

Pin 25

Pin 24

0

PCI

PCI

M

PCI

PCIF

1

PCIF

PCIF

PCIF Enable Control

TS

FS

PCI

0

0

Tristate all clocks

0

1

Reserved

M

0

30 MHz

M

1

33.3 MHz

1

0

25 MHz

1

1

37.5 MHz

PCIF continues to run in PCI STOP

mode. See table on page 4.

Spread direction is DOWN..