BT

Register/Memory Address

Before BT

After

d2

pc

$0000

$0006

$0000

$0016

Instruction Formats and Opcodes

Instruction

Words Cycles1 Type

Opcode

BT

<label

1

1/4

4

BT

>label

2

1/4

4

15

 

 

 

 

 

 

8

7

0

 

 

 

 

 

 

 

 

 

1

0

0

0

0

0

0

A

A A A A A A A 1

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

 

 

8

7

0

 

 

 

 

 

 

 

 

 

0

0

1

0

a

1

0

1

A A A 1 1 a a a

 

 

 

 

 

1

0

0

A A A A A

A A A A A A A a

 

 

 

 

 

 

 

 

 

 

Note 1: If the branch is not taken, it uses 1 cycle. If the branch is taken, it uses 4 cycles.

Instruction Fields

displacement

AAAAAAAA0

8-bit signed PC relative displacement

(<label)

 

 

displacement

aaaaaAAAAAAAAAAAAAA

20-bit signed PC relative displacement

(>label)

A0

 

 

 

A-110

SC140 DSP Core Reference Manual

Page 424
Image 424
Freescale Semiconductor SC140 specifications Register/Memory Address Before BT After