B nrp, Branch using nmi return pointer b nrp – Texas Instruments TMS320C67X/C67X+ DSP User Manual
Page 135
Branch Using NMI Return Pointer
B NRP
3-75
Instruction Set
SPRU733
Branch Using NMI Return Pointer
B NRP
Syntax
B (.unit) NRP
.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
dst
0 0 1 1 1 0 0 0 0 0 x 0 0 0 0 1 1 1 0 0 0 s p
3
1
5
1
1
1
Opcode map field used...
For operand type...
Unit
src2
xsint
.S2
Description
NRP is placed in the program fetch counter (PFC). This instruction also sets
the NMIE bit. The PGIE bit is unchanged.
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)
NRP
→
PFC
else nop
Notes:
1) This instruction executes on .S2 only. PFC is program fetch counter.
2) Refer to the chapter on interrupts for more information on NRP and
NMIE.
3) The execute packets in the delay slots of a branch cannot be interrupted.
This is true regardless of whether the branch is taken.
4) See section 3.5.2 on page 3-18 for information on branching into the
middle of an execute packet.