HANGZHOU SILAN MICROELECTRONICS CO.,LTD

REV:1.1

2009.11.19

Http: //www.silan.com.cn

Page 11 of 28

Reset value for timer is 1FFFFH, and it counts down.

WDT overflow reset signal is generated if the 17

Timer is reset if system is reset (including power-up reset, low-voltage reset and WDT overflow reset), HOLD is

cleared or reset instruction TMRST is executed.

Program is only executed when the 12

18. Carrier generator

Various carrier with different duty factors and frequencies are generated through setting high/low level duration by

carrier register (see CH0, CH1, CL0, CL1 description).

19. I/O port

SC73P2602 has 5 groups (20 in all) of I/O ports and most have both input/output modes (except P00 and P01

can only be used as input and P53 can only be used as output), details are as follows:

P00-P01: input pin with pull-up resistor. It can be used for keyboard scan input and input low level can clear

HOLD status;

P02-P03: input/output port. The input/output characteristic is decided by PR. When used as input port, it has pull-

up resistor and can be used as keyboard scan input, input low level can clear HOLD status; when used as output

pin, it can be used for keyboard scan output and output low level can drive LED directly.

P10-P13: same as P02;

P20-P23: same as P02;

P30-P33: same as P02;

P50-P52: same as P02;

P53: output infrared remote signal with carrier. There are two structures: push-pull structure is for external

infrared emitter driving and big current open-drain structure is for driving infrared emitter directly, with

opposite pole of the former structure.