ADSP-BF53x/BF56x Blackfin Processor Programming Reference
4-49
Program Sequencer
To determine when to service an interrupt, the controller logically ANDs
the three quantities in
ILAT
,
IMASK
, and the current processor priority
level.
Servicing the highest priority interrupt involves these actions:
1. The interrupt vector in the Event Vector Table (EVT) becomes the
next fetch address.
On an interrupt, most instructions currently in the pipeline are
aborted. On a service exception, all instructions after the excepting
instruction are aborted. On an error exception, the excepting
instruction and all instructions after it are aborted.
2. The return address is saved in the appropriate return register.
The return register is
RETI
for interrupts,
RETX
for exceptions,
RETN
for NMIs, and
RETE
for debug emulation. The return address is the
address of the instruction after the last instruction executed from
normal program flow.
3. Processor mode is set to the level of the event taken.
If the event is an NMI, exception, or interrupt, the processor mode
is Supervisor. If the event is an emulation exception, the processor
mode is Emulation.
4. Before the first instruction starts execution, the corresponding
interrupt bit in
ILAT
is cleared and the corresponding bit in
IPEND
is set.
Bit
IPEND[4]
is also set to disable all interrupts until the return
address in
RETI
is saved.
Summary of Contents for ADSP-BF53x Blackfin
Page 38: ...Conventions xxxviii ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 134: ...System Reset and Powerup 3 18 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 324: ...Instruction Overview 7 20 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 486: ...Instruction Overview 13 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 512: ...Instruction Overview 14 26 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 604: ...Instruction Overview 15 92 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 688: ...Instruction Overview 18 48 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 742: ...Instruction Overview 19 54 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Page 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...