MITSUBISHI MICROCOMPUTERS
3822 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
On-going Routine
Execute JSR
Interrupt request
(Note)
M (S) (PC
(S) (S) – 1
M (S) (PC
H
)
Push return address
on stack
M (S) (PC
(S) (S) – 1
M (S) (PC
H)
L
)
(S) (S) – 1
M (S) (PS)
(S) (S) – 1
Push return address
on stack
Push contents of processor
status register on stack
L
)
(S) (S)– 1
Subroutine
Interrupt
Service Routine
I Flag is set from “0” to “1”
Execute RTS
(S) (S) + 1
Fetch the jump vector
Execute RTI
(S) (S) + 1
POP return
address from stack
POP contents of
processor status
register from stack
(PC
(S) (S) + 1
(PC M (S)
L)
M (S)
(PS)
(S) (S) + 1
(PC M (S)
(S) (S) + 1
(PC M (S)
M (S)
H)
L)
POP return
address
from stack
H)
Note: Condition for acceptance of an interrupt
Interrupt enable flag is “1”
Interrupt disable flag is “0”
Fig. 10 Register push and pop at interrupt generation and subroutine call
Table 7 Push and pop instructions of accumulator or processor status register
Push instruction to stack
Pop instruction from stack
Accumulator
PHA
PHP
PLA
PLP
Processor status register
12
MITSUBISHI [ Mitsubishi Group ]
