SUB2

SUB2

Subtract Two 16-Bit Values (DALU)

SUB2

Operation

Assembler Syntax

 

Dn.H – Da.H → Dn.H

SUB2 Da,Dn

 

Dn.L – Da.L → Dn.L

 

 

Description

 

 

SUB2 Da,Dn

 

 

Performs a 32-bit subtraction of source register Da from Dn with borrow disabled between bits 15 and 16 so that the high and low words of each register are subtracted separately. The result is stored back in Dn. The extension byte of the result is undefined.

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 1

sub2 d0,d1

Register/Memory Address

D0

L1:D1

Example 2

sub2 d0,d1

Register/Memory Address

D0

L1:D1

Before

$00 0003 2A14

$0:$FF FFFE 2A18

Before

$00 7000 8000

$0:$FF 8000 7000

After

$0:$FF FFFB 0004

After

$0:$FF 1000 F000

A-392

SC140 DSP Core Reference Manual

Page 706
Image 706
Freescale Semiconductor SC140 specifications SUB2, Subtract Two 16-Bit Values Dalu, Sub2 d0,d1