
31
OSCIN
CK1
CK2
CK3
CK4
EXECUTE
(ENOP)
PIR OPEN
PIR CLOSE
RA(19:0)
RD(15:0)
EXECUTE
INTERRUPT SERVICE
COMMANDS
PRIMARY INSTRUCTION REGISTER (PIR)
FETCH
(NOP)
FETCH
(INR)
EXECUTE
(INR)
INTERRUPT
ADDRESS VALID
INTERRUPT
INSTRUCTION VALID
Figure 26. Interupt Timing
STATE1
INT
Assumes:
1. Interrupts enabled at time zero.
2. No mask bits set at time zero.
Do not care field
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