XOR AX,AX MOV AL,90H CWD 执行上述指令后,结果为()A (DX=0000, (AX=FF90HB (DX=FFFFH,(AX=0
XOR AX,AX MOV AL,90H CWD 执行上述指令后,结果为()
A (DX=0000, (AX=FF90H
B (DX=FFFFH,(AX=0090H
C (DX=FFFFH,(AX=FF90H
D(DX=0000, (AX=0090H
XOR AX,AX MOV AL,90H CWD 执行上述指令后,结果为()
A (DX=0000, (AX=FF90H
B (DX=FFFFH,(AX=0090H
C (DX=FFFFH,(AX=FF90H
D(DX=0000, (AX=0090H
分析下列程序:
DATA SEGMENT
NUM DB 06H
SUM DB?
DATA ENDS
STACK SEGMENT PARA STACK'STACK'
STAPN DW 100 DUP()
STACK ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA,SS:STACK
START:MOV AX,DATA
MOV DS,AX
PUSH AX
PUSH DX
CALL AAA
MOV AH,4CH
INT 21H
AAA PROC
XOR AX,AX
MOV DX,AX
INC DL
MOV CL,NUM
MOV CH,00H
BBB: ADD AL,DL
DAA
INC DL
LOOP BBB
MOV SUM,AL
RET
AAA ENDP
CODE ENDS
END START
(1) 程序执行到MOVAH,4CH语句时,AX=?DX=?SP=?
(2) BBB:ADD AL,DL语句的功能是什么?
(3) 整个程序的功能是什么?
下面的汇编语言源程序经汇编后,发现TEST [BX],OIH指令有语法错误,其该指令的正确形式应该是______。
DSEG SEGMENT
DAT DB 5,13,4,-2,6,23, 44, -1, 29,-3
CNT DW $-DAT
DSEG ENDS
SSEG SEGMENT STACK
DB 256 DUP (0)
SSEG ENDS
CSEG SEGMENT
ASSUME DS: DSEG, SS: SSEG, CS: CSEG
START PROC FAR
PUSH DS
XOR AX, AX
PUSH AX
MOV AX, DSEG
MOV DS,AX
XOR AX, AX
MOV BX, OFFSET DAT
MOV CX, CNT
LP: TEST [BX],01H
JZ NEXT
INC AH
ADD AL, [BX]
NEXT: INC BX
LOOP LP
SET
START ENDP
CSEG ENDS
END START
使状态标志位 CF 清零的错误指令()
A CLC
B XOR AX,AX
C SUB AX,AX
D MOV CF,0
A.OR AX,AX
B.SUB AX,AX
C.MOV C
D.0
E.CLC
A.NEG BX
B.NOT BX INC BX
C.XOR BX,0FFFFH
D.MOV AX,0 INC BX SUB AX,BX
A.它们都是按位操作的
B.指令XOR AX,AX执行后,结果不变,但是影响标志位
C.指令AND AL,0FH执行后,使AL的高4位清零,低4位不变
D.若DL=09H,CH=30H,执行OR,DL,CL后,结果为DL=39H
设初值AX=0119H,执行下列程序段后,AX=?
MOV CH,AH
ADD AL,AH
DAA
XCHG AL,CH
ADC AL,34H
DAA
MOV AH,AL
MOV AL,CH
HLT
完成41H送[2100H]、42H送[2101H]的正确程序是()。
A.MOV AL,41H MOV [2100H], AL INC AL MOV [2100H],AL
B.MOV SI, 2100H MOV [SI], ‘A’ INC SI MOV [SI], ‘B’
C.MOV AX,4241H MOV AX,AX
D.MOV AX, ‘AB’ MOV [2100H],AX
指出8086/8088下列指令中存储器操作数物理地址的计数表达式。
(1) MOV AL,[DI] (2) MOV AX,[BX+SI]
(3) MOV AL,8[BX+DI] (4) ADD AL,ES:[BX]
(5) SUB AX,[2400H] (6) ADC AX,[BX+DI+1200H]
(7) MOV CX,[BP+SI] (8) INC BYTE PTR [DI]