Question 2400 – Machine-Instructions

CMP
The CMP instruction compares two operands. It is generally used in conditional execution. This instruction basically subtracts one operand from the other for comparing whether the operands are equal or not. It does not disturb the destination or source operands. It is used along with the conditional jump instruction for decision making.
Syntax: CMP destination, source
MOV
The MOV instruction is the most important command in the 8086 because it moves data from one location to another. It also has the widest variety of parameters; so it the assembler programmer can use MOV effectively, the rest of the commands are easier to understand.
Syntax: MOV destination,source
JMP
Conditional execution often involves a transfer of control to the address of an instruction that does not follow the currently executing instruction. Transfer of control may be forward, to
execute a new set of instructions or backward, to re-execute the same steps.
Syntax: JMP label
CALL
The CALL instruction interrupts the flow of a program by passing control to an internal or external subroutine. An internal subroutine is part of the calling program. An external subroutine is another program.