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)=

假设（30H）=60H，（60H）=55H，则执行下列指令后，（A）=H,MOV R0,30HMOV A,@R0

设两个6位无符号BCD码分别存放在片内30H~32H和40H~42H单元中,试编写程序,求这两个多字节BCD码之和,并将结果存放回30H~32H单元中。补充完整以下程序。MOV R0,#30H MOV R1,#40H MOV R2,#3 CLR C LOOP:MOV A,@R0<br/>ADDC A,@R1 ______ MOV @R0,A INC R0 INC R1 ______ SJMP $

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)=

设R0=42H,(42H)=80H,A=48H,(50H)=08H,指出下列程序执行后，上述各单元内容的变化。 MOV A,@R0 MOV @R0,50H MOV 50H,A