The following table shows the list of Branching instructions with their meanings.
Opcode
Operand
Meaning
Explanation
JMP
16-bit address
Jump unconditionally
The program sequence is transferred to the memory address given in the operand.
Opcode
Description
Flag Status
JC
Jump on Carry
CY=1
JNC
Jump on no Carry
CY=0
JP
Jump on positive
S=0
JM
Jump on minus
S=1
JZ
Jump on zero
Z=1
JNZ
Jump on no zero
Z=0
JPE
Jump on parity even
P=1
JPO
Jump on parity odd
P=0
16-bit address
Jump conditionally
The program sequence is transferred to the memory address given in the operand based on the specified flag of the PSW.
Opcode
Description
Flag Status
CC
Call on Carry
CY=1
CNC
Call on no Carry
CY=0
CP
Call on positive
S=0
CM
Call on minus
S=1
CZ
Call on zero
Z=1
CNZ
Call on no zero
Z=0
CPE
Call on parity even
P=1
CPO
Call on parity odd
P=0
16-bit address
Unconditional subroutine call
The program sequence is transferred to the memory address given in the operand. Before transferring, the address of the next instruction after CALL is pushed onto the stack.
RET
None
Return from subroutine unconditionally
The program sequence is transferred from the subroutine to the calling program.
Opcode
Description
Flag Status
RC
Return on Carry
CY=1
RNC
Return on no Carry
CY=0
RP
Return on positive
S=0
RM
Return on minus
S=1
RZ
Return on zero
Z=1
RNZ
Return on no zero
Z=0
RPE
Return on parity even
P=1
RPO
Return on parity odd
P=0
None
Return from subroutine conditionally
The program sequence is transferred from the subroutine to the calling program based on the specified flag of the PSW and the program execution begins at the new address.
PCHL
None
Load the program counter with HL contents
The contents of registers H & L are copied into the program counter. The contents of H are placed as the high-order byte and the contents of L as the loworder byte.
RST
0-7
Restart
The RST instruction is used as software instructions in a program to transfer the program execution to one of the following eight locations.
Instruction
Restart Address
RST 0
0000H
RST 1
0008H
RST 2
0010H
RST 3
0018H
RST 4
0020H
RST 5
0028H
RST 6
0030H
RST 7
0038H
The 8085 has additionally 4 interrupts, which can generate RST instructions internally and doesnt require any external hardware. Following are those instructions and their Restart addresses −
