(2)已知(R1)=50H, (50H)=00H, CPU执行“DEC @R1”, 则
A: (R1)=4FH, (50H)=00H
B: (R1)=50H, (50H)=0FFH
C: (R1)=49H, (50H)=0FFH
D: (R1)=4FH, (4FH)=0FFH
A: (R1)=4FH, (50H)=00H
B: (R1)=50H, (50H)=0FFH
C: (R1)=49H, (50H)=0FFH
D: (R1)=4FH, (4FH)=0FFH
举一反三
- R1的内容为50H,执行下面的指令或指令组合,(),两(组)指令执行结果一样。 A: 指令ORL 50H #40H和指令组合MOV A @R1 ORL 50H A比较 B: 指令ORL A @R1和指令ANL A #50H比较 C: 指令ORL A @R1和指令MOV 50H R1 ORL A 50H比较 D: 指令ORL A R1和指令ORL A #50H比较
- 已知(A)=7FH,(50H)=FFH,(60H)=00H,执行下列指令后,XCHA,50HXCHA,60HXCHA,50H(A)=________,(50H)=________,(60H)=________。
- 已知(A)=01H,(SP)=50H,(DPTR)=100H。则下述程序段执行后 (A)、(B)、(SP)、(DPH)、Acc.7的结果为( )。 RL A MOV B,A MOVC A,@A+DPTR PUSH Acc SJMP $ ORG 100H DB 10H,20H,30H A: 30H,2,51H,01H,0 B: 20H,02H,4FH,10H,0 C: 30H,02H,51H,01H,1 D: 20H,4,50H,00H,1
- 根据下列程序段运行情况,将运行结果和指令分别补充完整。 (1)( );(A)=10H ( );(B)=10H ( );(A)=20H MOV 23H,A;(23H)=20H ( );(A)=21H MOV 24H,A;(24H)=21H INC A ;(A)=22H ( );(25H)= 22H (2)MOV A,#50H;(A)=( )H MOV R0,A;(R0)=( )H MOV @R0,#30H;(50H)=( )H ADD A,@R0;(A)=( )H MOVX @R0,A;(50H)=( )H
- R0=50H,(50H)=36H,执行MOV A, @R0后,A的内容是( )H。