B register, Branch using a register b – Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 131

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Branch Using a Register

B

3-71

Instruction Set

SPRU733

Branch Using a Register

B

Syntax

B (.unit) src2

.unit = .S2

Compatibility

C62x, C64x, C67x, and C67x+ CPU

Opcode

31

29

28

27

23

22

18

17

13

12

11

6

5

4

3

2

1

0

creg

z 0 0 0 0 0

src2

0 0 0 0 0 x 0 0 1 1 0 1 1 0 0 0 s p

3

1

5

1

1

1

Opcode map field used...

For operand type...

Unit

src2

xuint

.S2

Description

src2 is placed in the program fetch counter (PFC).

If two branches are in the same execute packet and are both taken, behavior
is undefined.

Two conditional branches can be in the same execute packet if one branch
uses a displacement and the other uses a register, IRP, or NRP. As long as only
one branch has a true condition, the code executes in a well-defined way.

Execution

if (cond)

src2

PFC

else nop

Notes:
1) This instruction executes on .S2 only. PFC is program fetch counter.

2) The execute packets in the delay slots of a branch cannot be interrupted.

This is true regardless of whether the branch is taken.

3) See section 3.5.2 on page 3-18 for information on branching into the

middle of an execute packet.

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