若(AX)=0122H,4个标志位CF、SF、ZF、OF的初始状态为0,执行指令SUB AX,0FFFH后,这4个标志位的状态是______。
A.(F)=0,(SF)=0,(ZF)=0,(OF)=0
B.(F)=1,(SF)=1,(ZF)=0,(OF)=0
C.(F)=0,(SF)=0,(ZF)=1,(OF)=1
D.(F)=1,(SF)=1,(ZF)=1,(0F)=1
A.(F)=0,(SF)=0,(ZF)=0,(OF)=0
B.(F)=1,(SF)=1,(ZF)=0,(OF)=0
C.(F)=0,(SF)=0,(ZF)=1,(OF)=1
D.(F)=1,(SF)=1,(ZF)=1,(0F)=1
A.(CF)=0,(SF)=0,(ZF)=0,(OF)=0
B.(CF)=1,(SF)=1,(ZF)=0,(OF)=0
C.(CF)=0,(SF)=0,(ZF)=1,(OF)=1
D.(CF)=1,(SF)=1,(ZF)=1,(OF)=1
A.(CF)=0,(SF)=0,(ZF)=0,(OF)=0
B.(CF)=1,(SF)=1,(ZF)=0,(OF)=0
C.(CF)=0,(SF)=0,(ZF)=1,(OF)=1
D.(CF)=1,(SF)=1,(ZF)=1,(OF)=1
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
假定ax=6987h,执行指令cmpax,0eb30h后,则标志位CF和OF的状态()。
A)0,0
B)0,1
C)1,0
D)1,1
假设(CS)=3000H,(DS)=4000H,(ES)=2000H,(SS)=5000H,(Ax)=2060H, (BX)=3000H,(CX)=5,(DX)=0,(SI)=2060H,(DI)=3000H,(43000H)=0A006H,(23000H)=0B116H,(33000H)=0F802H,(25060)=00BOH,(SP)=0FFFEH,(CF)=1, (DF)=l,试写出下列各条指令单独执行完后,有关寄存器及存储单元的内容,若影响条件标志,需给出条件标志SF、ZF、OF、CF的值。 (1)SBB AX,BX (2)CMP AX,WORD PTR[SI+0FAOH] (3)MUL BYTE PTR[BX] (d)AAM (5)DIV BH (6)SAR AX,CL (7)XOR AX.0FFE7 H (8)REP STOSB (9)JMP WORD PYR[BX] (10)XCHG AX,ES:[BX+SI]
试编子程序,返回16位二进制数中指定位段的零状态。已知:
入口参数:AX=16位二进制数;
BL=高4位b1、低4位b0;
其中b1和b0分别为位段最高位编号和最低位的编号(15~0)。
出口参数:CE=0;
若指定位段为0,ZF=1,否则ZF=0。
注意:若b1小于b0,则不予处理,返回CF=1。