Monday, February 29, 2016

8051 JNZ Instruction

Jump if Accumulator Not Zero

InstructionJNZ relative address
FunctionJump if Accumulator Not Zero
Bytes2
Cycles2
Encoding0 1 1 1 0 0 0 0 A7...A0
OperationPC = PC + 2
IF A <> 0
PC = PC + relative address
DescriptionIf any bit of the Accumulator is a one, JNZ branches to the indicated address; otherwise, it proceeds with the next instruction. The branch destination is computed by adding the signed relative-displacement in the second instruction byte to the PC, after incrementing the PC twice. The Accumulator is not modified. No flags are affected.
Flags AffectedC AC F0 RS1 RS0 OV P
ExampleThe Accumulator originally holds 00H. The following instruction sequence,
JNZ LABEL1
INC A
JNZ LABEL2
sets the Accumulator to 01H and continues at label LABEL2.
Bytes: Number of bytes required to encode the instruction.
Cycles: Number of instruction cycles required to execute the instruction. Note that there are 12 oscillator cycles to one instruction cycle on a standard 8051.
Encoding: Lists the byte encoding for the instruction.
Operation: Lists, step-by-step, the operations performed by the instruction.
Flags Affected: are highlighted in Bold



Related topics:
8051 Program Branching Instructions   |   8051 ACALL Instruction   |   8051 LCALL Instruction   |   8051 RET Instruction   |   8051 RETI Instruction   |   8051 JMP Instruction   |   8051 AJMP Instruction   |   8051 LJMP Instruction   |   8051 SJMP Instruction   |   8051 JZ Instruction   |   8051 CJNE Instruction   |   8051 DJNZ Instruction   |   8051 NOP Instruction

List of topics: 8051

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