8051 instruction set ,addressing modes-1

When we add two numbers the destination address must always be.

• some immediate data

• any register

• accumulator

• memory

If SUBB A,R4 is executed, then actually what operation is being applied?

• R4+A

• R4-A

• A-R4

• R4+A

Which instructions affect the program counter?

• Call & Return

• . Call & Jump

• Push & Pop

• Return & Jump

A valid division instruction always makes:

• CY=0,AC=1

• CY=1,AC=1

• CY=0,AC=0

• no relation with AC and CY

Which of the following instruction perform as of indirect RAM to accumulator?

• MOV A, Rn

• MOV @Ri, A

• MOV A, @Ri

• MOV Rn, A

A CALL instruction allows specifying ______address in the instruction and calling subroutine within ______ program memory block.

• 2byte, 3K

• 11bit, 2K

• 9bit, 2K

• 1byte, 3K

Which of the following instruction perform the move accumulator to external RAM of 16bit address?

• MOV @ DPTR, A

• MOVX @ Ri, A

• MOV A, @ Ri

• MOVX @ DPTR, A

Which of the following instruction perform jump indirect relative to DPTR

• JMP A+DPTR

• JMP DPTR

• JMP @A+DPTR

• SJMP A+DPTR

Which of the following instruction is wrong

• INC DPTR

• MOV @DPTR, A

• MOV A, @A+DPTR

• DEC DPTR

What is the Result of RR A instruction if accumulator contains 1000 0000.

• 0000 0001

• 0000 0000

• 0100 0000

• 0000 0010