D17133CS datasheet(210/289 Pages) NEC

210 / 289 page

CHAPTER 18

INSTRUCTION SET

195

(3)

ADDC r, m

Add data memory to general register with carry flag

<1> OP code

00010

<2> Function

When CMP=0, (r)

← (r) + (m) +CY

Adds the data memory contents to the general register contents with carry flag CY, and stores the result

in general register indentified as r.

When CMP=1, (r) + (m) + CY

The result is not stored in the register. Carry flag CY and zero flag Z are changed according to the result.

By using this ADDC instruction, two or more words can be easily added.

Sets carry flag CY, if a carry occurs as a result of the addition; resets the carry flag CY if no carry occurs.

If the addition result is other than zero, zero flag Z is reset, regardless of compare flag CMP.

If the addition result is zero, with the compare flag reset (CMP=0), the zero flag Z is set.

If the addition result is zero, with the compare flag set (CMP=1), the zero flag Z is not changed.

Addition can be executed in binary 4-bit or BCD. The BCD flag for program status word PSWORD specifies

which kind of addition is to be executed.

<3> Example 1

Adds the 12-bit contents for addresses 0.0DH through 0.0FH to the 12-bit contents for addresses 0.2DH

through 0.2FH, and stores the result in the 12-bit contents for address 0.0DH to 0.0FH, when row address

0 (0.00H-0.0FH) of bank 0 is specified as a general register:

(0.0FH)

← (0.0FH) + (0.2FH)

(0.0EH)

← (0.0EH) + (0.2EH) + CY

(0.0DH)

← (0.0DH) + (0.2DH) + CY

MEM00D

MEM

0.0DH

MEM00E

MEM

0.0EH

MEM00F

MEM

0.0FH

D17133CS Datasheet(PDF) 210 Page - NEC