delay.asm

单片机at89c52 超声波测距离的设计

;-------------------------------------
;延时100机器周期*参数（1~65535）
;-------------------------------------
                    NAME     DELAY
?PR?_DELAY?DELAY    SEGMENT  CODE
                    PUBLIC   _DELAY
                    RSEG     ?PR?_DELAY?DELAY
_DELAY:             PUSH     ACC               ;2
		    MOV      A,     R7         ;1
                    JZ       DELA1             ;2
	            INC      R6                ;1
DELA1:              MOV      R5,    #50D       ;2
                    DJNZ     R5,    $          ;2
                    DJNZ     R7,    DELA1      ;2
                    DJNZ     R6,    DELA1      ;2
                    POP      ACC               ;2
                    RET                        ;2
;
                    END