MOVES.4F
SC140 DSP Core Reference Manual
A-67
BFD
Branch If False Using a Delay Slot (AGU)
BFD
Description
Status and Conditions that Affect Instruction
Status and Conditions Changed by Instruction
None.
Example
BFD lbl
Operation
Assembler Syntax
If T==0, then PC + displacement
→
PC
BFD <label
BFD >label
BFD <label
BFD >label
Branches to label if the true bit is cleared. If the T bit is cleared, the program continues executing at
location PC + displacement. If the T bit is set, the PC is updated to point to the next execution set, and the
program continues executing sequentially. The displacement, calculated by the assembler and linker, is a
two’s complement integer that represents the relative distance from the current PC to the destination label.
The assembler determines if the PC relative displacement is a short branch (
<
label [–2
8
≤
displacement
<
2
8
, W]) or a long branch (
>
label [–2
20
≤
displacement
<
–2
8
, W and 2
8
≤
displacement
<
2
20
, W]). The
execution set in the delay slot immediately following the BFD instruction is executed unconditionally after
the execution set containing the BFD instruction.
Register Address
Bit Name
Description
SR[1]
T
True bit
Instruction
Result
cmpeq.w #$35,d1
Not equal, so T bit in SR cleared.
bfd lbl move.w #$29,d1
Branch taken, move.w executed.
inc d1
Increment executed in the delay slot.
move.w #$47,d2
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
- - - -
Skipped over.
lbl move.w #$1A,d4
Execution continues here at lbl.
Register/Memory Address
Before
After
SR
$00E0 0000
Содержание SC140 DSP Core
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Страница 385: ...BMCHG W SC140 DSP Core Reference Manual A 71 u16 iiiiiiiiiiiiiiii 16 bit unsigned immediate data ...
Страница 388: ...A 74 SC140 DSP Core Reference Manual BMCHG W s16 AAAAAAAAAAAAAAAA 16 bit signed SP address offset ...
Страница 391: ...BMCLR SC140 DSP Core Reference Manual A 77 u16 iiiiiiiiiiiiiiii 16 bit unsigned immediate data ...
Страница 454: ...A 140 SC140 DSP Core Reference Manual DECA u5 iiiii 5 bit unsigned immediate data 1 set by the assembler ...
Страница 463: ...DI SC140 DSP Core Reference Manual A 149 15 8 7 0 DI 1 1 4 1 0 0 1 1 1 1 1 0 1 1 1 1 1 0 1 ...
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Страница 592: ...A 278 SC140 DSP Core Reference Manual MOVE L a32 aaaaaaaaaaaaaaaaAAAAAAAAAAAAAAAA 32 bit absolute long address ...
Страница 618: ...A 304 SC140 DSP Core Reference Manual MOVES 4F s15 sssssssssssssss Signed 15 bit offset ...
Страница 638: ...A 324 SC140 DSP Core Reference Manual MPYR ...
Страница 660: ...A 346 SC140 DSP Core Reference Manual OR W s16 AAAAAAAAAAAAAAAA Signed 16 bit SP address offset ...
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