Events and Interrupts
4-44
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
If there is not a need for non-interruptible code inside the service routine,
it is good programming practice to enable nesting immediately. This
avoids unnecessary delay to high priority interrupt routines. For example:
isr:
[--SP] = RETI;
/* enable nesting */
[--SP] = (R7:0, P5:0);
/* push core registers */
[--SP] = ASTAT;
/* push arithmetic status */
/* place core of service routine here */
ASTAT = [SP++];
/* pop arithmetic status */
(R7:0, P5:0) = [SP++];
/* pop core registers */
RETI = [SP++];
/* disable nesting */
RTI;
/* return from interrupt */
isr.end:
See
“Nesting of Interrupts” on page 4-51
for more details on interrupt
nesting.
Emulation Events, NMI, and Exceptions use a technique similar to “nor-
mal” interrupts. However, they have their own return register and return
instruction counterparts.
Table 4-9
provides an overview.
Table 4-9. Return Registers and Instructions
Name
Event Class
Return Register
Return
Instruction
EMU
Emulation
RETE
RTE
RST
Reset
RETI
RTI
NMI
NMI
RETN
RTN
EVX
Exception
RETX
RTX
Reserved
Reserved
-
-
IVHW
Hardware Error
RETI
RTI
IVTMR
Core Timer
RETI
RTI
IVG7
Interrupt 7
RETI
RTI
Содержание ADSP-BF53x Blackfin
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Страница 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 780: ...Product Identification Register 21 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 994: ...Instructions Listed By Operation Code C 194 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...