ABCD Add Decimal with Extend

ABCD Add Decimal with Extend

Adds the source operand to the destination operand along with the extend bit, and stores the result in the destination location. The addition is performed using binary-coded decimal arithmetic. The operands, which are packed binary-coded decimal numbers, can be addressed in two different ways:

Data Register to Data Register
The operands are contained in the data registers specified in the instruction
Memory to Memory
The operands are addressed with the predecrement addressing mode using the address registers specified in the instruction.

This operation is a byte operation only.

Operation:ABCD
Syntax:
ABCD Dy, Dx
ABCD -(Ay), -(Ax)
Data Size:
Byte
Flags:
XNZVC
*U*U*
X Set the same as the carry bit
N Undefined
Z Cleared if the result is nonzero; unchanged otherwise
V Undefined
C Set if a decimal carry was 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
1100Rx10000R/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