8051 ADDC Instruction

Addition with Carry

Instruction	ADDC A, src-byte
Function	Add with Carry
Description	ADDC simultaneously adds the byte variable indicated, the carry flag and the Accumulator contents, leaving the result in the Accumulator. The carry and auxiliary-carry flags are set respectively, if there is a carry-out from bit 7 or bit 3, and cleared otherwise. When adding unsigned integers, the carry flag indicates an overflow occurred. OV is set if there is a carry-out of bit 6 but not out of bit 7, or a carry-out of bit 7 but not out of bit 6; otherwise OV is cleared. When adding signed integers, OV indicates a negative number produced as the sum of two positive operands or a positive sum from two negative operands. Four source operand addressing modes are allowed: register, direct, register-indirect, or immediate.
Example	The Accumulator holds 0C3H (11000011B) and register 0 holds 0AAH (10101010B) with the carry flag set. The following instruction, ADDC A,R0 leaves 6EH (01101110B) in the Accumulator with AC cleared and both the Carry flag and OV set to 1.
Variants	ADDC A,Rn ADDC A, direct address ADDC A,@Ri ADDC A,#immediate data

Instruction	ADDC A,Rn
Bytes	1
Cycles	1
Encoding	0 0 1 1 1 n n n
Operation	A = A + C + Rn
Flags Affected	C AC F0 RS1 RS0 OV P
Example	ADDC A, R0
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

Instruction	ADDC A,direct address
Bytes	2
Cycles	1
Encoding	0 0 1 1 0 1 0 1 A7...A0
Operation	A = A + C + (direct)
Flags Affected	C AC F0 RS1 RS0 OV P
Example	ADDC A, 20h
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

Instruction	ADDC A,@Ri
Bytes	1
Cycles	1
Encoding	0 0 1 1 0 1 1 i
Operation	A = A + C + (Ri)
Flags Affected	C AC F0 RS1 RS0 OV P
Example	ADDC A, @R1
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

Instruction	ADDC A, #immediate data
Bytes	2
Cycles	1
Encoding	0 0 1 1 0 1 0 0 D7...D0
Operation	A = A + C + immediate data
Flags Affected	C AC F0 RS1 RS0 OV P
Example	ADDC A, #03h
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 Arithmetic Operation Instructions   |   8051 ADD Instruction   |   8051 SUBB Instruction   |   8051 INC Instruction   |   8051 DEC Instruction   |   8051 MUL Instruction   |   8051 DIV Instruction   |   8051 DA Instruction

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List of topics: 8051

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