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
12h blk2 db 21h,43h,65h,87h,90h count equ $-blk2 sum0 db 6 dup (00h) data ends code segment assume cs:code, ds:data start: mov ax, data mov ds, ax lea si, blk1 lea bx,blk2 lea di,sum0 mov cx, count clc aa:mov al, [si] adc al, [bx] daa mov [di], al inc si inc bx inc di loop aa mov al, 00h adc al, 00h mov [di], al mov ah,4ch int 21h code ends end start
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
执行下面的程序段后,AX寄存器中的内容是______。
ARRAY DW 10DUP(2)
XOR AX, AX
MOV CX, 0AH
MOV SI, 12H
NEXT: ADD AX,ARRAY[SI]
SUB SI, 2H
Lool NEXT
A.20 B.30
C.32 D.40
A.A.20
B.B.30
C.C.32
D.D.40
A.OR AX,AX
B.SUB AX,AX
C.MOV C
D.0
E.CLC
A、0002H
B、0001H
C、0FFFEH
D、0003H
A.指令XOR AX,AX执行后,AX内容不变,但设置了标志位
B.指令OR DX,1000H 执行后,将DX最高位置1,其余各位置О
C.指令AND AX,OFH执行后,分离出AL低四位
D.NOT AX,执行后,将AX清0
A.NEG BX
B.NOT BX INC BX
C.XOR BX,0FFFFH
D.MOV AX,0 INC BX SUB AX,BX