loading
KEYSM1: MOV A,R2 ；使第一列为0 MOV DPTR,#0FF21H MOVX @DPTR,A NOP RL A MOV R2,A MOV DPTR,#0FF23H MOVX A,@DPTR CPL A ；读行值 NOP NOP NOP ANL A,#0FH JNZ KEYSM2 INC R0 ；无键继续扫描下一行 DJNZ R3,KEYSM1 SJMP KEYSM10
KEYSM2: CPL A ；有键，计算键值 JB 0E0H,KEYSM3 MOV A,#00H SJMP KEYSM7
KEYSM3: JB 0E1H,KEYSM4 MOV A,#08H SJMP KEYSM7
KEYSM4: JB 0E2H,KEYSM5 MOV A,#10H SJMP KEYSM7
KEYSM5: JB 0E3H,KEYSM10 MOV A,#18H KEYSM7: ADD A,R0 CLR 0D4H CJNE A,#10H,KEYSM9 KEYSM9: JNC KEYSM10 MOV DPTR,#DATA2 MOVC A,@A+DPTR KEYSM10: RET DATA2: DB
07H,04H,08H,05H,09H,06H,0AH,0BH ；键值表（0—F） DB 01H,00H,02H,0FH,03H,0EH,0CH,0DH EN
四、实验小结
通过本次实验学习P3口、P1口简单使用。学习延时程序的编写和使用。了解步进电机控制
的基本原理。掌握步进电机转动编程方法。