MCS—51指令系统中,执行下列程序后,堆栈指针SP的内容为_____。
MOV SP,#30H
MOV A,20H
LCALL 1000
MOV 20H,A
SJMP $
MOV SP,#30H
MOV A,20H
LCALL 1000
MOV 20H,A
SJMP $
举一反三
- 80C51指令系统中,执行下列程序后,堆栈指针SP的内容为( )。MOV SP,#30HMOV A,20HLACALL 1000MOV 20H,ASJMP $ A: 00H B: 30H C: 32H D: 07H
- 51指令系统中,执行下列程序后,程序计数器PC的内容为______ ORG 0000H MOV DPTR, #1000 MOV A, #00H MOV 20H, A LJMP 1500H END
- 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
- 指令 MOV R0,20H 执行前 (R0)=30H, (20H)=38H,执行后(R0)=?
- 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