Program execution transfer instructions in 8086 microprocessor

Prerequisite – Branching instructions in 8085 microprocessor

Program execution transfer instructions are similar to branching instructions and refer to the act of switching execution to a different instruction sequence as a result of executing a branch instruction.

The two types of program execution transfer instructions are:

1. Unconditional
2. Conditional

1. Unconditional Program Execution Transfer Instructions – These instruction always execute.

Opcode	Operand	Explanation	Example
CALL	address	calls a subroutine and saves the return address on the stack	CALL 2050
RET	none	returns from the subroutine to the main program	RET
JUMP	address	transfers the control of execution to the specified address	JUMP 2050
LOOP	address	loops through a sequence of instructions until CX=0	LOOP 2050

Here the address can be specified directly or indirectly.

2. Conditional Program Execution Transfer Instructions : These instructions only execute when the specified condition is true.

Opcode	Operand	Explanation	Example
JC	address	jump if CF = 1	JC 2050
JNC	address	jump if CF = 0	JNC 2050
JZ	address	jump if ZF = 1	JZ 2050
JNZ	address	jump if ZF = 0	JNZ 2050
JO	address	jump if OF = 1	JO 2050
JNO	address	jump if OF = 0	JNO 2050
JP	address	jump if PF = 1	JP 2050
JNP	address	jump if PF = 0	JNP 2050
JPE	address	jump if PF = 1	JPE 2050
JPO	address	jump if PF = 0	JPO 2050
JS	address	jump if SF = 1	JS 2050
JNS	address	jump if SF = 0	JNS 2050
JA	address	jump if CF=0 and ZF=0	JA 2050
JNBE	address	jump if CF=0 and ZF=0	JNBE 2050
JAE	address	jump if CF=0	JAE 2050
JNB	address	jump if CF=0	JNB 2050
JBE	address	jump if CF = 1 or ZF = 1	JBE 2050
JNA	address	jump if CF = 1 or ZF = 1	JNA 2050
JE	address	jump if ZF = 1	JE 2050
JG	address	jump if ZF = 0 and SF = OF	JG 2050
JNLE	address	jump if ZF = 0 and SF = OF	JNLE 2050
JGE	address	jump if SF = OF	JGE 2050
JNL	address	jump if SF = OF	JNL 2050
JL	address	jump if SF != OF	JL 2050
JNGE	address	jump if SF != OF	JNGE 2050
JLE	address	jump if ZF = 1 or SF != OF	JLE 2050
JNG	address	jump if ZF = 1 or SF != OF	JNG 2050
JCXZ	address	jump if CX = 0	JCXZ 2050
LOOPE	address	loop while ZF = 1 and CX = 0	LOOPE 2050
LOOPZ	address	loop while ZF = 1 and CX = 0	LOOPZ 2050
LOOPNE	address	loop while ZF = 0 and CX = 0	LOOPNE 2050
LOOPNZ	address	loop while ZF = 0 and CX = 0	LOOPNZ 2050

Here the address can be specified directly or indirectly.
CF is carry flag
ZF is zero flag
OF is overflow flag
PF is parity flag
SF is sign flag
CX is the register