TSTEQ

TSTEQ

Test for Equal to Zero (DALU)

TSTEQ

Operation

Assembler Syntax

If Dn == 0, then 1 → T, else 0 → T

TSTEQ Dn

Description

 

TSTEQ Dn

 

Sets the T bit in SR if the source data register (Dn) is equal to zero; otherwise, it clears the T bit.

Status and Conditions that Affect Instruction

None.

Status and Conditions Changed by Instruction

Register Address

Bit Name

Description

SR[1]

T

Set if the source operand is equal to zero and cleared if the source

 

 

operand is not equal to zero.

Example

tsteq d1

Register/Memory Address

D1

SR

Before

$00 0000 0000

$00E4 0000

After

$00E4 0002

Instruction Formats and Opcodes

Instruction

Words

Cycles

Type

TSTEQ Dn

1

1

1

Note: ** indicates serial grouping encoding.

Opcode

158 70

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

Instruction Fields

Dn

FFF

 

 

Single Source/Destination Data Register

 

 

 

000

 

D0

010

D2

100

D4

110

D6

 

 

 

 

 

 

 

 

 

 

 

001

 

D1

011

D3

101

D5

111

D7

 

 

 

 

 

 

 

 

 

Note:

This instruction

can specify D8-D15 as operands by using a prefix.

 

 

 

 

 

 

 

 

 

 

 

 

 

Note:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A-414

SC140 DSP Core Reference Manual

Page 728
Image 728
Freescale Semiconductor SC140 Test for Equal to Zero Dalu, Tsteq d1, If Dn == 0, then 1 → T, else 0 → T, Tsteq Dn