BTD

Register/Memory Address

Before BTD

After

d1

d2

d4

pc

$0035

$0000

$0000

$0006

$002A

$0000

$001A

$0016

Instruction Formats and Opcodes

Instruction

Words Cycles1 Type

Opcode

15

8

7

0

BTD <label

1

1/4

4

1 0 0 0 0 0 0 A A A A A A A A 0

 

 

 

 

15

 

 

8

7

0

BTD >label

2

1/4

4

 

 

 

 

 

 

0

0

1

0 a 1 0 0

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 minus the time used by the execution set in the delay slot. The cycle count for this instruction cannot be less than 1 cycle.

Instruction Fields

displacement

AAAAAAAA0

8-bit signed PC relative displacement

(<label)

 

 

displacement

aaaaaAAAAAAAAAAAAAA

20-bit signed PC relative displacement

(>label)

A0

 

 

 

A-112

SC140 DSP Core Reference Manual

Page 426
Image 426
Freescale Semiconductor SC140 specifications $0035 $0000 $0006 $002A $001A $0016