举一反三
- ORG 0 LJMP START ORG 30HSTART: MOV SP,#50H MOV DPTR,#3000H MOV R0,#20H MOV A,#23H MOV R2,#0FH SETB 01H SETB C ADDC A,@R0 INC R0 MOV @R0,A LOOP:DJNZ R2, LOOP SWAP A PUSH ACC INC DPH MOVX @DPTR,A POP B RR A ADD A,B MOV P1,A END(21H)= (R2)= (A)= (B)= (3100H)=
- ORG 0 LJMP START ;跳转到(PC)=0030H处 ORG 30H START:MOV R0,#30H MOV A,#12H SETB C ADDC A,R0 MOV @R0,A SWAP A INC A MOV DPTR,#2000H INC DPH MOV P1,A INC A MOVX @DPTR,A XCH A,R0 RL A ;累加器A内容循环左移 PUSH ACC RL A ;累加器A内容循环左移 POP ACC END(A)= (R0)= (DPTR)= (P1)= (30H)=
- 判断以下指令的正误。 (1) MOV R1,R2 (2)MOV 20H,@R3 (3)DEC DPTR (4)INC DPTR (5)MOVX A,@R1 (6)MOVC A,@DPTR (7)PUSH DPTR(8)CLR R1 (9)MOV 20H,30H (10)MOV F0,C (11) CPL R7 (12)RC A
- 已知程序执行前有(A)=02H,(SP)=42H,(41H)=FFH,(42H)=FFH。 POP DPH POP DPL MOV DPTR,#3000H RL A MOV B,A MOVC A,@A+DPTR PUSH Acc MOV A,B INC A MOVC A,@A+DPTR PUSH Acc RET ORG 3000H DB 10H,80H,30H,80H,50H,80H 程序执行后, (A)=;(SP)=;(41H)=;(42H)=;PC=
- 已知程序执行前有A = 02H,SP = 42H,(41H) = FFH,(42H) = FFH。下述程序执行后,(42H) =( )。 POP DPH POP DPL MOV DPTR,#3000H RL A MOV B,A MOVC A,@A+DPTR PUSH Acc MOV A,B INC A MOVC A,@A+DPTR PUSH Acc RET ORG 3000H DB 10H,80H,30H,80H,50H,80H
内容
- 0
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
- 1
下列哪条指令是正确的( )a) PUSH R2 b) ADD R0,Ac) MOVX A @DPTR d) MOV @R,A A: PUSH R2 B: ADD R0,A C: MOVX A @DPTR D: MOV @R,A
- 2
例: MOV SP, #18H ; (SP)=? MOV A, #30H ; (A)=? MOV DPTR, #1000H ; (DPTR)=? PUSH A ; (SP)=? (19H)=? PUSH DPH ; (SP)=? (1AH)=? PUSH DPL ; (SP)=? (1BH)=? POP DPL ; (DPL)=? (SP)=? POP DPH ; (DPH)=? (SP)=、 POP A ; (A)=? (SP)=?
- 3
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
- 4
下列指令错误的个数是______ 。(1)MOV 28H,@R2 (2)DEC DPTR (3)INC DPTR (4)CLR R0 (5)CPL R5 (6)MOV R0,R1(7)PUSH DPTR (8)MOV F0,C (9)MOV F0,ACC.3 (10)MOVX A,@R1 (11)MOVC,30H (12)RLC R0