Jsr First Instruction Of A Fast Interrupt - Motorola DSP56000 Manual

EXCEPTION PROCESSING STATE (INTERRUPT PROCESSING)
MAIN
PROGRAM
n1
n2
INTERRUPT CONTROL CYCLE 1
INTERRUPT CONTROL CYCLE 2
FETCH
DECODE
EXECUTE
INSTRUCTION CYCLE COUNT
i = INTERRUPT
ii = INTERRUPT INSTRUCTION WORD
n = NORMAL INSTRUCTION WORD
Figure 7-11 JSR First Instruction of a Fast Interrupt
MOTOROLA
FAST INTERRUPT
VECTOR
JSR
NOT USED
(a) Instruction Fetches from Memory
INTERRUPT SYNCHRONIZED AND
RECOGNIZED AS PENDING
i
i
n1 JSR —
n1 JSR NOP
n1 JSR
1 2 3 4
(b) Program Controller Pipeline
PROCESSING STATES
INTERRUPTS RE-ENABLED
ii2 ii3 ii4 iin RTI
ii2 ii3 ii4 iin
NOP ii2 ii3 ii4
5 6 7 8 9
LONG INTERRUPT
SUBROUTINE
ii2
ii3
ii4
iin
RTI
— n2
RTI NOP n2
iin RTI NOP n2
10 11 12 13
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