第四部分:计算题
1.(A)=3BH,执行 ANL A,#9EH指令后,(A)=?(CY)=?
2.JNZ rel为2B指令,放于1038H,转移目标地址是134AH,求偏移量rel=?
3.若(A)=C3H,(R0)=AAH,执行 ADD A,R0后,(A)=? (CY)=? (OV)=?
(AC)=?
4. 若(A)=50H,(B)=A0H,执行 MUL AB后,(A)=? (B)=? (OV)=? (CY)=?
5.SJMP OE7H 为2B 指令,放于F010H,目标地址=?
6.晶振fosc=6MHz,T0工作在模式1,最大定时=?
阅读并分析程序题
1. 位地址为M ,N,Y,程序如下:
MOV C, M
ANL C, N-
MOV Y, C
MOV C, M
ANL C, N
ORL C, Y
MOV Y, C
求程序功能表达式.
2. 程序如下:
2506H M5: MOV SP,#58H;
2509H MOV 10H,#0F0H;
250CH MOV 11H,#0BH;
250FH ACALL XHD;(PC)+2—>PC,{
2511H MOV 20H,11H
2514H M5A: SJMP M5A
XHD: PUSH 10H
PUSH 11H
POP 10H
POP 11H
RET
问:(1)执行POP 10H 后堆栈内容?
(2)执行M5A:SJMP M5A后,(SP)=? (20H)=?
3. 程序存储空间表格如下:
地址 2000H 2001H 2002H 2003H ┄ |
内容 3FH 06H 3BH 4FH ┄ |
已知:片内RAM的20H中为01H,执行下列程序后(30H)为多少?
MOV A,20H
INC A
MOV DPTR,#2000H
MOVC A,@A+DPTR
CPL A
MOV 30H,A
END:SJMP END
4.(R0)=4BH,(A)=84H,片内RAM(4BH)=7FH,(40H)=20H
MOV A,@R0 ; 7FH->A
MOV @R0,40H ; 20H->4BH
MOV 40H,A ; 7FH->40H
MOV R0,#35H
问执行程序后,R0,A和4BH,40H单元内容的变化如何?
5.设R0=20H,R1=25H,(20H)=80H,(21H)=90H,(22H)=A0H,(25H)=A0H,(26H)=6FH,(27H)=76H,下列程序执行后,结果如何?
CLR C
MOV R2,#3
LOOP: MOV A,@R0
ADDC A,@R1
MOV @R0,A
INC R0
INC R1
DJNZ R2,LOOP
JNC NEXT
MOV @R0,#01H
SJMP $
NEXT: DEC R0
SJMP $
(20H)=_______, (21H)=______, (22H)=______, (22H)=______,
CY=_______,A=_______, R0=_______,R1=_______
6.阅读下列程序并回答问题。
CLR C
MOV A,#9AH
SUUB A,60H
ADD A,61H
DA A
MOV 62H,A
(1) 问该程序执行何重操作?
(2) 已知出值:(60H)=23H,(61H)=61H,请问运行后:(62H)=_______?
7.解读下列程序,然后填写有关寄存器的内容。
(1) MOV R1,#48H
MOV 48H,#51H
CJNE ·R1,#51H,00H
JNC NEXT1
MOV A,#0FFH
SJMP NEXT2
NEXT1: MOV A,#0AAH
NEXT2: SJMP NEXT2
累加器 A=( )
(2) MOV A,#0FBH
MOV PSW,#10H
ADD A,#7FH
若PSW=00, 当执行完上述程序后,将PSW各位状态填入下表:
PSW
CY |
AC |
F0 |
RS1 |
RS0 |
OV |
F1 |
P |
|
|
|
|
|
|
|
|
8.分析程序段:
CLR C
MOV A,#9AH
SUUB A,60H
ADD A,61H
DA A
MOV 62H,A
(1) 程序执行何种操作?
(2) 若已知出值:(60H)=24H,(61H)=72H,则运行后,(62H)=_______。
9.设(R0)=7EH,DPTR=10FEH,片内RAM 中7EH和7FH两单元的内容分别是FFH和38H,请写出下列程序段的每条指令的执行结果。
INC @R0
INC R0
INC @R0
INC DPTR
INC DPTR
INC DPTR
10. 片内RAM 中(59H)=50H,执行下列程序段.
MOV A,59H
MOV R0,A
MOV A,#0
MOV @R0,A
MOV A,#25H
MOV 51H,A
MOV 52H,#70H
问A=________,(50H)=_______,(51H)=________,(52H)=________