Freescale Semiconductor SC140 Imac d4,d5,d6, Dn ± Da.L * Db.L → Dn, Imac ±Da,Db,Dn

Models: SC140

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IMAC

IMAC

Integer Multiply-Accumulate (DALU)

Operation

 

Assembler Syntax

Dn ± (Da.L * Db.L) → Dn

IMAC ±Da,Db,Dn

IMAC

Description

IMAC ±Da,Db,Dn

Performs signed integer-multiplication on the LP contents of two source data registers (Da and Db) and adds or subtracts the product to or from a destination data register (Dn). The default operation is the addition of the product to the destination register.

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 1

imac d4,d5,d6

Register/Memory Address

D4

D5

L6:D6

EMR

Before

$FF FFFF FFFB

$00 0000 0003

$0:$00 0000 0008

$0000 0000

After

$0:$FF FFFF FFF9

$0000 0000

A-180

SC140 DSP Core Reference Manual

Page 494
Image 494
Freescale Semiconductor SC140 specifications Imac d4,d5,d6, Dn ± Da.L * Db.L → Dn, Imac ±Da,Db,Dn