8051 JNC Instruction

Jump if Carry not set

Instruction	JNC relative address
Function	Jump if Carry not set
Bytes	2
Cycles	2
Encoding	0 0 1 0 1 0 0 1 A7...A0
Operation	PC = PC + 2 IF (C) = 0 PC = PC + relative address
Description	If the carry flag is a 0, JNC branches to the address indicated; otherwise, it proceeds with the next instruction. The branch destination is computed by adding the signal relative-displacement in the second instruction byte to the PC, after incrementing the PC twice to point to the next instruction. The carry flag is not modified.
Flags Affected	C AC F0 RS1 RS0 OV P
Example	The carry flag is set. The following instruction sequence, JNC LABEL1 CPL C JNC LABEL2 clears the carry and causes program execution to continue at the instruction identified by the 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

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Related topics:
8051 Boolean Variable Manipulation Instructions   |   8051 CPL Instruction   |   8051 CLR Instruction   |   8051 SETB Instruction   |   8051 ORL Instruction   |   8051 ANL Instruction   |   8051 MOV Instruction   |   8051 JC Instruction   |   8051 JBC Instruction   |   8051 JB Instruction   |   8051 JNB Instruction

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List of topics: 8051

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