IMPY

IMPY

Integer Multiply (DALU)

Operation

Assembler Syntax

Da.L * Db.L → Dn

IMPY Da,Db,Dn

IMPY

Description

IMPY Da,Db,Dn

Performs a signed integer multiplication on the low portions of two signed source data registers (Da, Db) and stores the 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 register.

Example impy d3,d4,d0

Register/Memory Address

Before

D3

 

$FF FFFF 0202

D4

 

$00 0000 FFFE

L0:D0

 

514$0202 x –2 $FFFE –1028 $FBFC

After

$0:$FF FFFF FBFC

Instruction Formats and Opcodes

Instruction

Words

Cycles

Type

Opcode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

 

 

8

7

 

 

 

 

 

 

0

IMPY

Da,Da,Dn

1

1

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

*

1

0

1

0

F

F

F

1

1

1

0

1

j

j

 

 

 

 

 

15

 

 

 

 

 

 

8

7

 

 

 

 

 

 

0

IMPY

Da,Db,Dn

1

1

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

*

1

0

1

0

F

F

F

0

1

J

J

J

J

J

Note: ** indicates serial grouping encoding.

SC140 DSP Core Reference Manual

A-187

Page 501
Image 501
Freescale Semiconductor SC140 specifications Integer Multiply Dalu, Da.L * Db.L → Dn, Impy Da,Db,Dn