MACUU

 

 

 

 

MACUU

Fractional Multiply-Accumulate

MACUU

 

 

Unsigned By Unsigned (DALU)

 

Operation

Assembler Syntax

Dn + (Dc.L * Dd.L) → Dn

MACUU Dc,Dd,Dn

 

Description

MACUU Dc,Dd,Dn

Performs unsigned fractional multiplication of the unsigned 16-bit LP of one data register (Dc) by the unsigned 16-bit LP of the other data register (Dd). It then adds the zero-extended 32-bit product to a data register (Dn).

Status and Conditions that Affect Instruction

None.

Status and Conditions Changed by Instruction

Register Address

Bit Name

Description

Ln

L

Clears the Ln bit in the destination register.

EMR[2]

DOVF

Set if the result cannot be represented in 40 bits.

Example

macuu d2,d3,d1

Register/Memory Address

D2

D3

L1:D1

Before

$00 0000 FFFF

$00 0000 FFFF

$0:$00 7FFF FFFF

After

$0:$02 7FFC 0001

EMR

$0000 0000

1.111 1111 1111 1111$FFFF x 1.111 1111 1111 1111$FFFF

1 1.111 1111 1111 1100 0000 0000 0000 0001$01 FFFC 0001

+0.111 1111 1111 1111 1111 1111 1111 1111$00 7FFF FFFF 10 0.111 1111 1111 1100 0000 0000 0000 0001$02 7FFC 0001

SC140 DSP Core Reference Manual

A-243

Page 557
Image 557
Freescale Semiconductor SC140 Macuu, Fractional Multiply-Accumulate, Unsigned By Unsigned Dalu Operation Assembler Syntax