能帮我看个程序吗，不知道对不对
单片机接8155后再接1602LCD，
为什么判忙的时候要先给P0接口写入“1”？
ORG 0000H
AJMP BFLED
BFLED:NOP
NOP
NOP
MOV SP, #70H
NOP
NOP
RS BIT P1.0
RW BIT P1.1
E BIT P2.6
MOV 50H, #00H ;显示缓存
MOV 51H, #00H
MOV 52H, #00H
MOV 53H, #00H
MOV 54H, #00H
MOV 55H, #00H
MOV 30H,#01H;清屏
ACALL SEND
ACALL WC
MOV 30H,#38H;8位2行,5*7矩阵
ACALL SEND
ACALL WC
MOV 30H,#06H;文字不动,光标自动右移
ACALL SEND
ACALL WC
MOV 30H,#0C0H;写入显示起始地址,第二行第一个位置
ACALL SEND
ACALL WC
MOV 31H,R0
MOV R0,#50H;从50H到55H为显示缓存
XH:MOV 30H,@R0
ACALL SEND
ACALL WD
INC R0
CJNE R0,#56H,XH
MOV R0,31H
RET;显示完
WC: CLR RS;写入指令子程序
CLR RW
CLR E
ACALL PD
SETB E
RET
WD: SETB RS;写入数据子程序
CLR RW
CLR E
ACALL PD
SETB E
RET
PD: MOV 30H,#0FFH;判断显示忙否子程序
ACALL SEND
CLR RS
SETB RW
CLR E
NOP
SETB E
MOV DPTR,#8300H
MOV A,#05H
MOVX @DPTR,A
MOV DPTR, #8302H ;读入数据
MOVX A, @DPTR
MOV P0,A
JB P0.7,PD
RET
SEND:MOV DPTR,#8300H;写入8155子程序
MOV A,#07H
MOVX @DPTR,A
MOV DPTR,#8302H
MOV A,30H
MOVX @DPTR,A
RET
END |
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