Texas Instruments MSP430x4xx User Manual

Page 70

Advertising
background image

Instruction Set

3-36

RISC 16−Bit CPU

DADD[.W]

Source and carry added decimally to destination

DADD.B

Source and carry added decimally to destination

Syntax

DADD

src,dst

or DADD.W

src,dst

DADD.B

src,dst

Operation

src + dst + C −> dst (decimally)

Description

The source operand and the destination operand are treated as four binary
coded decimals (BCD) with positive signs. The source operand and the carry
bit (C) are added decimally to the destination operand. The source operand
is not affected. The previous contents of the destination are lost. The result is
not defined for non-BCD numbers.

Status Bits

N: Set if the MSB is 1, reset otherwise
Z: Set if result is zero, reset otherwise
C: Set if the result is greater than 9999

Set if the result is greater than 99

V: Undefined

Mode Bits

OSCOFF, CPUOFF, and GIE are not affected.

Example

The eight-digit BCD number contained in R5 and R6 is added decimally to an
eight-digit BCD number contained in R3 and R4 (R6 and R4 contain the
MSDs).

CLRC

; clear carry

DADD

R5,R3

; add LSDs

DADD

R6,R4

; add MSDs with carry

JC

OVERFLOW ; If carry occurs go to error handling routine

Example

The two-digit decimal counter in the RAM byte CNT is incremented by one.

CLRC

; clear carry

DADD.B

#1,CNT

; increment decimal counter

or

SETC
DADD.B

#0,CNT

;

DADC.B CNT

Advertising