ADDX

ADD Extended

Adds the source operand and the extend bit to the destination operand and stores the result in the destination location. The operands can be addressed in two different ways:

Data register to data register
The data registers specified in the instruction contain the operands.
Memory to memory
The address registers specified in the instruction address the operands using the predecrement addressing mode.

The size of the operation can be specified as byte, word, or long.

Operation:ADDX
Syntax:
ADDX Dy, Dx
ADDX -(Ay), -(Ax)
Data Size:
Byte
Word
Long
Flags:
XNZVC
*****
X Set the same as the carry bit
N Set if the result is negative; cleared otherwise
Z Cleared if the result is nonzero; unchanged otherwise
V Set if an overflow occurs; cleared otherwise
C Set if a carry is generated; cleared otherwise
Normally, the Z condition code bit is set via programming before the start of an operation. This allows successful tests for zero results upon completion of multiple-precision operations.
Format:
15141312111098 76543210
1101Rx1Size00R/MRy

Rx the source register.

Ry the destination register.

R/M Specifies the operand addressing mode:

R/MOperation
0Uses data registers
1Uses address registers or memory

Size the size of the operation:

SizeOperation
00Byte
01Word
10Long


Last modified June 10, 2022: instruction fields (f3b3701)