MACSU

 

 

 

 

MACSU

Fractional Multiply-Accumulate

MACSU

 

 

Signed By Unsigned (DALU)

 

Operation

Assembler Syntax

Dn + (Dc.H * Dd.L) → Dn

MACSU Dc,Dd,Dn

 

Description

MACSU Dc,Dd,Dn

Performs signed fractional multiplication of the signed 16-bit HP of one data register (Dc) in a register pair (Dc and Dd) by the unsigned 16-bit LP of the other data register (Dd). It then adds the sign-extended 32-bit product to a destination 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

macsu d0,d1,d4

Register/Memory Address

D0

D1

L4:D4

EMR

Before

$FF C000 0000

$00 0000 0001

$0:$00 0000 0000

After

$0:$FF FFFF 8000

$0000 0000

SC140 DSP Core Reference Manual

A-239

Page 553
Image 553
Freescale Semiconductor SC140 specifications Macsu d0,d1,d4, Dn + Dc.H * Dd.L → Dn, Macsu Dc,Dd,Dn