t7.asm

来自「《8051单片机彻底研究》一书的随书光盘」· 汇编 代码 · 共 32 行

;PROGRAM NAME:T7.ASM
;TEST TIMER0 MODE 2:8-BIT COUNT UP
;
COUNT   EQU     92    ;100uS FOR XTAL=11.0592MHz
CHK_BIT REG     P3.2
LED     REG     P3.7
;
        ORG     0
        MOV     R0,#00H
        DJNZ    R0,$    ;WAIT
        CLR     CHK_BIT
        MOV     SP,#40H
;
        MOV     A,TMOD
        ANL     A,#11110000B
        CLR     ACC.3   ;GATE=0
        CLR     ACC.2   ;C/T=0
        SETB    ACC.1   ;TIMER0 M1=1
        CLR     ACC.0   ;TIMER0 M0=0
        MOV     TMOD,A
        MOV     TH0,#(256-COUNT)
        MOV     TL0,#00
        CLR     TF0     ;CLEAR TF0
        SETB    TR0
;
LOOP    JNB     TF0,LOOP  ;TF0=0
;TF0=1
OVER    CLR     TF0     ;CLEAR TF0
        CPL     CHK_BIT
$NEXT   SJMP    LOOP
;