8255lcd1.asm

在达盛实验箱下的lcd单片机显示

 ;8255扩展OCMJ2X8模块测试程序
 ;------------------------------------------------
        PA         EQU  0CFA0H
        PB         EQU  0CFA1H
        PCC        EQU  0CFA2H
        PCTL       EQU  0CFA3H 
        STOBE0     EQU  70H        ;PC0复位控制字
        STOBE1     EQU  71H        ;PC0置位控制字

        CSEG  AT  0000H
		LJMP  START
		
		CSEG  AT  4100H
;----------------------------------------

START:  MOV DPTR, #PCTL
        MOV A, #88H
        MOVX @DPTR, A              ;置PA口输出,PC口高4位输入,低4位输出                
        
        MOV DPTR, #PCTL
        MOV A, #STOBE0
        MOVX @DPTR, A	
        MOV A, #0F4H
		ACALL SUB2
		ACALL DELAY                ;清屏

START1: MOV R0, #01H
		MOV R1, #3CH
HE1:    MOV DPTR, #PCC
        MOVX A, @DPTR
        JB ACC.7, HE1
        ACALL SUB1
	    ACALL SUB2
	    DJNZ R1, HE1
        ACALL DELAY
        ACALL DELAY
	    ACALL DELAY
        LJMP START1        
;-------------------------------------------------------
DELAY: 	MOV R2, #23H
DEL0:   MOV R4, #06FH
DEL1:   MOV R6, #06FH
DEL2:   DJNZ R6, DEL2
		DJNZ R4, DEL1
		DJNZ R2, DEL0
		RET
;-------------------------------------------------------
SUB2:   MOV DPTR, #PA
        MOVX @DPTR, A
        MOV DPTR, #PCTL
        MOV A, #STOBE1
        MOVX @DPTR, A 
        INC R0
HE2:    MOV DPTR, #PCC
        MOVX A, @DPTR
	    JNB ACC.7, HE2
	    MOV DPTR, #PCTL
        MOV A, #STOBE0
        MOVX @DPTR, A 
		RET
;-----------------------------------------
SUB1:   MOV A, R0   	;显示“北京理工达盛科技有限公司”
		MOVC A,@A+PC
		RET
	 DB 0F0H,01D,00D,17D,17D,0F0H,02D,00D,30D,09D
	 DB 0F0H,03D,00D,32D,77D,0F0H,04D,00D,25D,04D
	 DB 0F0H,05D,00D,20D,79D,0F0H,06D,00D,42D,02D
	 DB 0F0H,01D,01D,31D,38D,0F0H,02D,01D,28D,28D
	 DB 0F0H,03D,01D,51D,48D,0F0H,04D,01D,47D,62D
	 DB 0F0H,05D,01D,25D,11D,0F0H,06D,01D,43D,30D

		END