SC72131

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

REV:2.0

2004.08.03

Http: www.silan.com.cn

Page 4 of 11

PIN DESCRIPTION

Pin NO.

SDIP-22

SOP-20

Pin Name

Description

1

1

OSCIN

22

20

OSCOUT

Connects 4.5M or 7.2M crystal oscillator to supply reference

frequency and internal clock.

2

NC

--

3

2

PERIOD

4

3

DIN

5

4

CLOCK

6

5

DOUT

Serial I/O ports, These pins transfer data to and from the controller

to set divisors and dividing modes, and to control the general-

purpose counter and general-purpose I/O ports.

7

6

OT1

8

7

OT2

9

8

OT3

10

9

OT4

•N channel open drain port pins.

data.

•If the serial data TBC bit is set to 1, a time base signal (8Hz) can

•These pins are set to the OFF state when power is turn on.

11

10

1

IO

13

12

2

IO

•CMOS structure allows free use of these ports for input or output.

•Ports are set for input when the power is turned on.

12

11

IFIN

•Input pin for measure general-purpose counter frequencies. The

frequency measurement function has such uses as measuring

intermediate frequencies (IF)

•These pin feature built-in amps, Data are input by capacitor

coupling.

(To be continued)