Program execution transfer instructions in 8086 microprocessor
These instructions are used to transfer/branch the instructions during an execution. There are two types of branching instructions. The unconditional branch and conditional branch.
The Unconditional Program execution transfer instructions are as follows.
Opcode
| Operand
| Description
|
|---|
CALL
| address
| Used to call a procedure and save their return address to the stack.
|
RET
| ----
| Used to return from the procedure to the main program.
|
JMP
| address
| Used to jump to the provided address to proceed to the next instruction.
|
LOOP
| address
| Used to loop a group of instructions until the condition satisfies, i.e., CX = 0
|
Now let us see the Conditional Program execution transfer instructions.
Opcode
| Operand
| Description
|
|---|
JC
| address
| Used to jump if carry flag CY = 1
|
JNC
| address
| Used to jump if no carry flag (CY = 0)
|
JE/JZ
| address
| Used to jump if equal/zero flag ZF = 1
|
JNE/JNZ
| address
| Used to jump if not equal/zero flag ZF = 0
|
JO
| address
| Used to jump if overflow flag OF = 1
|
JNO
| address
| Used to jump if no overflow flag OF = 0
|
JP/ JPE
| address
| Used to jump if parity/parity even PF = 1
|
JNP/ JPO
| address
| Used to jump if not parity/parity odd PF = 0
|
JS
| address
| Used to jump if sign flag SF = 1
|
JNS
| address
| Used to jump if not sign SF = 0
|
JA/ JNBE
| address
| Used to jump if above/not below/equal instruction satisfies.
|
JAE/ JNB
| address
| Used to jump if above/not below instruction satisfies.
|
JBE/ JNA
| address
| Used to jump if below/equal/ not above instruction satisfies.
|
JG/ JNLE
| address
| Used to jump if greater/not less than/equal instruction satisfies.
|
JGE/ JNL
| address
| Used to jump if greater than/equal/not less than instruction satisfies.
|
JL/ JNGE
| address
| Used to jump if less than/not greater than/equal instruction satisfies.
|
JLE/ JNG
| address
| Used to jump if less than/equal/if not greater than instruction satisfies.
|
JCXZ
| address
| Used to jump to the provided address if CX = 0
|
LOOPE/ LOOPZ
| address
| Used to loop a group of instructions till it satisfies ZF = 1 & CX = 0
|
LOOPNE/ LOOPNZ
| address
| Used to loop a group of instructions till it satisfies ZF = 0 & CX = 0
|
Published on 11-Mar-2019 11:32:18
