2

ICS9158-07

Pin Configuration

Pin Descriptions

24-Pin SOIC

Functionality

Note 1:

All frequencies in MHz, assuming 14.31818 MHz reference frequency.

Note 2:

OE equals Low, tristates CLK2, CLK12(0:2), CLK1(0:3), the REF, 24 MHz

and 48 MHz clocks keep running.

PIN NUMBER

PIN NAME

TYPE

DESCRIPTION

1, 8, 13, 14

CLK1A

OUT

CPU clock 1 outputs.

2

X2

OUT

Crystal connection.

3

X1

IN

Crystal connection.

4

VDD

PWR

Digital POWER SUPPLY (+5V).

5, 12

GND

PWR

Digital GROUND/

6

48 MHz

OUT

48 MHz clock output.

7

24 MHz

OUT

24 MHz floppy disk/combination I/O clock output.

9

AGND

PWR

ANALOG GROUND.

10

OE

IN

OUTPUT ENABLE. Tristates all clock outputs when low.

11, 17, 21, 22

CLK12

OUT

CPU clock 12 outputs.

15

FS2

IN

CPU clock frequency select 2.

16

AVDD

PWR

ANALOG power supply (+5V).

18

REF

OUT

14.318 MHz reference clock output.

19

GND

PWR

Digital GROUND.

20

VDD

PWR

Digital POWER SUPPLY (+5V).

22

CLK2

OUT

CPU clock 2 outputs.

23

FS1

IN

CPU clock frequency select #1.

24

FS0

IN

CPU clock frequency select #0.

OE

FS2

FS1

FS0

CLK2

Ratio

CLK2

(Mhz)

CLK1(0:3)

(Mhz)

CLK12(0:2)

(MHz)

1

0

0

0

29/13 X1

31.9

16

31.9

1

0

0

1

29/13 X1

31.9

16

31.9

1

0

1

0

29/13 X1

31.9

16

31.9

1

0

1

1

29/13 X1

31.9

16

31.9

1

1

0

0

14/3 X1

66.8

33.4

66.8

1

1

0

1

7/2 X1

50.1

25

50.1

1

1

1

0

14/3 X1

66.8

33.4

66.8

1

1

1

1

21/5 X1

60.1

30

60.1

0

X

X

X

--

Tristate

Tristate

Tristate