ICS650-14B

Networking System Clock

MDS 650-14B A

2

Revision 082800

Printed 11/15/00

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

PRELIMINARY INFORMATION

Pin Descriptions

Key: XI, XO = crystal connections; I = Input; I(Pu) = Input with pull up O = Output; P = power supply connection; TI = tri level input

Number

Name

Type

Description

1

SELB0

T I

Select pin for CLKB. See Table 2.

2

X2

XO

Crystal connection. Connect to 25 MHz crystal or leave unconnected for a clock input.

3

X1/ICLK

XI

Crystal connection. Connect to 25 MHz fundamental crystal or clock input.

4

VDD

P

Connect to +3.3 V or +5 V. Must be same as other VDDs.

5

SELB1

I(Pu)

Select pin for CLK B. See table 2.

6

GND

P

Connect to ground.

7

CLKB

O

Selectable clock output. See Table 2.

8

CLKC

O

Selectable clock output. See Table 3.

9

CLKA5

O

Selectable clock output. See Table 1.

10

25M

O

25.0 MHz clock output.

11

OE

I(Pu)

Output Enable. Tri-states all output clocks when low. Internal pull-up.

12

CLKA1

O

Selectable clock output. See Table 1.

13

CLKA4

O

Selectable clock output. See Table 1.

14

GND

P

Connect to ground.

15

SELA1

T I

Select pin for CLKA1:4 and CLKA5 outputs. See Table 1.

16

VDD

P

Connect to +3.3V or +5.0V. Must be same as other VDDs.

17

CLKA3

O

Selectable clock output. See Table 1.

18

CLKA2

O

Selectable clock output. See Table 1.

19

SELA0

T I

Select pin for CLKA1:4 and CLKA5 outputs. See Table 1.

20

SELC

T I

Select pin for CLKC output. See Table 3.

Pin Assignment

1

16

2

3

4

15

14

13

VDD

CLKA5

X2

VDD

20 pin (150 mil) SSOP

5

6

7

8

12

11

10

9

25M

SELA0

X1/ICLK

SELB0

CLKA2

SELC

CLKA3

CLKA1

OE

CLKC

CLKB

18

17

19

20

GND

SELB1

CLKA4

GND

SELA1

SELC

CLKC

0

CLKB/4

M

62.5

1

125

Table 3

0 = connect directly to ground

1 = connect directly to VDD

M = leave unconnected (floating)

SELB1

SELB0

CLKB

0

0

30

0

M

27

0

1

48

1

0

83.33

1

M

19.44

1

1

80

Table 2

SELA1

SELA0

CLKA1:4

CLKA5

0

0

33.33

66.66

0

M

50

75

0

1

66.67

133.33

M

0

100

33.33

M

M

33.33

83.33

M

1

50

125

1

0

33.33

100

1

M

25

75

1

1

66.67

100

Table 1