Question

单片机试题求助

1．已知（R0）=20H, (20H ) =10H, (P0) =30H, (R2) =20H, 执行如下程序段后( 40H ) =
MOV @R0 , #11H
MOV A , R2
ADD A , 20H
MOV PSW , #80H
SUBB A , P0
XRL A , #45H
MOV 40H , A
2. 已知 ( R0 )=20H, (20H )=36H, (21H) =17H, (36H) =34H, 执行过程如下：
MOV A , @R0
MOV R0 , A
MOV A , @R0
ADD A , 21H
ORL A , #21H
RL A
MOV R2 , A
RET
则执行结束（R0）= (R2)=
3. 执行下面一段程序；
MOV SP, #60H
MOV A, #10H
MOV B, #01H
PUSH A
PUSH B
POP A
POP B
A , B的内容是：(A)= (B)=
4. 设在31H单元存有＃23H,执行下面程序：
MOV A, 31H
ANL A, #0FH
MOV 41H, A
MOV A, 31H
ANL A, #0F0H
SWAP A
MOV 42H, A
则(41H)= (42H)=
5．已知 ( 40H)=56, (51H )=16H, (42H )=01H (43H )=00H写出执行的结果。
MOV R0，#40H
MOV A， @R0
MOVB,A
INC R0
MOVA,@R0
RL A
MOV @R0, A；
INC R0
MOVA,B
MOV@R0,A
RR A
INC R0
MOV @R0,A
(40H) = (41H) = (42H )= (43H)=
5．已知 ( 30H)=78, (31H )=12H, (32H )=00H (33H )=00H写出执行的结果。
MOV R1，#30H
MOV A， @R1
MOVB,A
INC R1
MOVA,@R1
DIV AB
MOV @R1, A；
INC R1
MOVA,B
MOV@R1,A
CPL A
INC R1
MOV @R1,A
(30H) = (31H) = (32H )= (33H)=

7、说明下列各条指令中源操作数的寻址方式
1）．MOV R6，A
2）．MOV A，50H
3）．JBC ACC.3,rel
4）．MOVDPTR，#5200H
5）．MOVCA，@A+PC
6）．MOVA，@R0

Answer 1

1.(40H)=44H；
2.（R0）= 36H (R2)= E2H
3. (A)= 10H (B)=01H
4. (41H)= 03H (42H)= 02H
5. 貌似缺少(41H)的已知条件，且需确认（40H）=56后面有没有H；(40H) = 56 (41H) = (42H )=56 (43H)=56循环右移
5.(30H) =78 (31H) =04H (32H )=00H (33H)=FFH
7.
1)寄存器寻址2）直接寻址3）位寻址4）立即寻址5）变址间接寻址6）寄存器间接寻址

Answer 2

EA
PSEN
这个在书上都能找到的，你怎么学的？