watchdog.a51

来自「at89c51ed2看门狗程序」· A51 代码 · 共 48 行

$INCLUDE   (reg_c51.INC)
org 000h
ljmp begin

;/**
; * FUNCTION_PURPOSE:this function setup Watchdog.
; * FUNCTION_INPUTS:void
; * FUNCTION_OUTPUTS:void
; */
org 0100h
begin:


;Selected Time-out
;
;mode X1 12 clock periods per peripheral clock cycle.
;mode X2  6 clock periods per peripheral clock cycle.
;
;ORL WDTPRG,#00h   (2^14 - 1) machine cycles, 16. 3 ms @ FOSCA =12 MHz
;ORL WDTPRG,#01h   (2^15 - 1) machine cycles, 32.7 ms @ FOSCA=12 MHz
;ORL WDTPRG,#02h   (2^16 - 1) machine cycles, 65. 5 ms @ FOSCA=12 MHz
;ORL WDTPRG,#03h   (2^17 - 1) machine cycles, 131 ms @ FOSCA=12 MHz
;ORL WDTPRG,#04h   (2^18 - 1) machine cycles, 262 ms @ FOSCA=12 MHz
;ORL WDTPRG,#05h   (2^19 - 1) machine cycles, 542 ms @ FOSCA=12 MHz
;ORL WDTPRG,#06h   (2^20 - 1) machine cycles, 1.05 s @ FOSCA=12 MHz
;ORL WDTPRG,#07h   (2^21 - 1) machine cycles, 2.09 s @ FOSCA=12 MHz

ORL WDTPRG,#07;/*2.275s @ FOSCA=11.059200 MHz */

;/* watchdog start sequence */
MOV WDTRST,#1Eh;
MOV WDTRST,#0E1h;

loop:                         /* end less */

;/***********************************************
;*                 PROGRAM                      *
;************************************************/

;  /* watchdog reset sequence */
   MOV WDTRST,#1Eh;
   MOV WDTRST,#0E1h;

JMP loop

END