delay.asm

51单片机与ps2键盘接口程序

	H_DATA		BIT 	P3.2
	H_CLK		BIT		P3.4

	?PR?DELAY30US SEGMENT CODE 
	PUBLIC DELAY30US
	RSEG ?PR?DELAY30US
	
	;	abc	XDATA	0A00H
	
;35.8US
DELAY30US:
		PUSH	05H           ;2
		MOV		r5,#50        ;25
DE30S1:
		DJNZ	r5,DE30S1     ;2*14=28
		POP	05h           ;2
		RET
;******************************************************************
	?PR?DELAY10US SEGMENT CODE 
	PUBLIC DELAY10US
	RSEG ?PR?DELAY10US
;16.3US
DELAY10US:      
		PUSH	05H          ;2
		MOV     r5, #20       ;10
DE10S1: 
		DJNZ    r5, DE10S1   ;5*2=10
		POP	05H	     ;2
		RET

	?PR?CLSSIGNAL SEGMENT CODE 
	PUBLIC CLSSIGNAL
	RSEG ?PR?CLSSIGNAL
CLSSIGNAL:          
;WHEN SYSTEM SEND INFORMATION TO PINPAD, SEND STOP BIT AT END, THEN NEXT A 
;SEND OPERATION. SO WAITTING STOP BIT FINISHED.
CLSL1:          
		PUSH    05H
CLSL1_U:
		MOV     R5, #6EH
CLSL2:  JNB     H_DATA, CLSL1_U
		JNB     H_CLK, CLSL1_U
		DJNZ    R5, CLSL2
		POP     05H
		RET

		END