MPYSU

 

 

 

 

MPYSU

Fractional Multiply

MPYSU

 

 

Signed By Unsigned (DALU)

 

Operation

Assembler Syntax

 

Dc.H * Dd.L → Dn

MPYSU Dc,Dd,Dn

 

Description

 

 

MPYSU Dc,Dd,Dn

 

 

Performs signed fractional multiplication between the signed 16-bit HP of the first register (Dc) of a data register pair with the unsigned 16-bit LP of the second register (Dd). It then stores the sign-extended 32-bit product in 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 registers.

Example

mpysu d4,d5,d6

Register/Memory Address

D4

D5

L6:D6

Before

$FF C000 0001

$FF E000 0002

After

$0:$FF FFFF 0000

Instruction Formats and Opcodes

Instruction

Words

Cycles

Type

MPYSU Dc,Dd,Dn

1

1

1

Note: ** indicates serial grouping encoding.

Opcode

158 70

0 * 1 0 1 1 F F F 1 1 0 1 0 e e

Instruction Fields

Dc,Dd

ee

Data Register Pairs

00 D0,D1

01 D2,D3

10 D4,D5

11 D6,D7

Note: This instruction can specify D8-D15 as operands by using a prefix.

SC140 DSP Core Reference Manual

A-325

Page 639
Image 639
Freescale Semiconductor SC140 specifications Mpysu d4,d5,d6, Dc.H * Dd.L → Dn, Mpysu Dc,Dd,Dn