Freescale Semiconductor SC140 specifications Dc.L * Dd.H → Dn, Mpyus Dc,Dd,Dn

Models: SC140

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MPYUS

 

 

 

 

MPYUS

Fractional Multiply

MPYUS

 

 

Unsigned By Signed (DALU)

 

Operation

Assembler Syntax

 

Dc.L * Dd.H → Dn

MPYUS Dc,Dd,Dn

 

Description

 

 

MPYUS Dc,Dd,Dn

 

 

Performs signed fractional multiplication between the unsigned 16-bit LP of the first register (Dc) of a data register pair with the signed 16-bit HP 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 mpyus d2,d3,d4

Register/Memory Address

Before

D2

 

$FF FF00 0002

D3

 

$FF C000 0042

L4:D4

 

1.100 $C000 (–2–1)

x 0.000 0000 0000 0010$0002 (2–14) 1.111 1111 1111 1111$FFFF (–2–15)

After

$0:$FF FFFF 0000

Instruction Formats and Opcodes

Instruction

Words

Cycles

Type

MPYUS Dc,Dd,Dn

1

1

1

Note: ** indicates serial grouping encoding.

Opcode

158 70

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

SC140 DSP Core Reference Manual

A-327

Page 641
Image 641
Freescale Semiconductor SC140 specifications Dc.L * Dd.H → Dn, Mpyus Dc,Dd,Dn