Freescale Semiconductor SC140 Dmacsu Multiply Signed By Unsigned and Dmacsu, Dmacsu d2,d3,d5

Models: SC140

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DMACSU

DMACSU Multiply Signed By Unsigned and DMACSU

Accumulate With Right Shifted Data Register (DALU)

Operation

Assembler Syntax

[Dn>>16] + Dc.H * Dd.L → Dn

DMACSU Dc,Dd,Dn

(Dc signed, Dd unsigned)

 

Description

DMACSU Dc,Dd,Dn

Shifts Dn 16 bits to the right with bit 39 sign-extended into bits [39:24]. Adds the result to the product of a signed fraction in Dc.H and an unsigned fraction in Dd.L. Places the result into Dn.

Dc and Dd are a data register pair. The operands are in the HP and LP of each register, respectively.

This instruction is optimized for multi-precision multiplication support.

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

dmacsu d2,d3,d5

Register/Memory Address

D2

D3

L5:D5

EMR

Before

$FF F002 0000

$00 0000 00D1

$0:$00 0001 0000

After

$0:$FF FFE5 E345

$0000 0000

Instruction Formats and Opcodes

Instruction

Words Cycles Type Opcode

15

8

7

0

DMACSU Dc,Dd,Dn

1

1

1

Note: ** indicates serial grouping encoding.

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

SC140 DSP Core Reference Manual

A-155

Page 469
Image 469
Freescale Semiconductor SC140 specifications Dmacsu Multiply Signed By Unsigned and Dmacsu, Dmacsu d2,d3,d5