()=F0H, (R1)=40H, and (40H)=0FH. After execution of an instruction XCHD A, @R1, accumulator will be,( )
A. 00H
B. F0H
C. 0FH
D. FFH
查看答案
Instruction “MOV A, @R1” will ( )
A. copy R1 to the accumulator
B. copy the accumulator to R1
C. copy the contents of internal RAM pointed by R1 to accumulator
D. copy the contents of external RAM pointed by R1 to accumulator
Which of the following instruction will move the number 27H in the accumulator? ( )
A. MOV A, 27
B. MOV A, #27H
C. MOV A, 27H
D. MOV A, @27
Which of the following is invalid instruction? ( )
A. MOVX R0, @DPTR
B. MOVC A, @A+PC
C. XCH A, 10H
D. XCH A, @R1
Which of the following instructions is an example for the direct addressing mode? ( )
A. MOV A, @R0
B. MOV R0, #10H
C. MOV 10H, A
D. MOV R5, A
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