51单片机与扩展芯片8155的连接
我使用8155 ACC;
LK3: ACALL DIR;
ACALL KS1;
JNZ LK3;
POP ACC;
RET;
NEXT: INC R4;
MOV A,R2;
JNB ACC.7,KND;
RL A;
MOV R2,A;
JNB ACC.7,KND;
RL A
MOV R2,A;
AJMP LK4;
KND: AJMP KEY1;
DIR:MOV R7,#0FFH;
DIR1:MOV R6,#0FFH;
DIR2:MOV R5,#01FH;
DIR3:DJNZ R5,DIR3;
DJNZ R6,DIR2;
DJNZ R7,DIR1;
