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CHAPTER 16 INTERRUPT FUNCTION
User
’
s Manual U15017EJ2V0UD
16.11.1 Interrupt acknowledge processing time
The time shown in Table 16-7 is required to acknowledge an interrupt request. After the time shown in this table
has elapsed, execution of the interrupt processing program is started.
Table 16-7. Interrupt Acknowledge Processing Time
(Unit: Clock = 1/f
CLK
)
Vector Table
IROM
EMEM
Branch
Destination
IROM, PRAM
EMEM
PRAM
EMEM
Stack
IRAM
PRAM
EMEM
IRAM
PRAM
EMEM
IRAM
PRAM
EMEM
IRAM
PRAM
EMEM
Vectored
Interrupts
26
29
37 + 4n
27
30
38 + 4n
30
33
41 + 4n
31
34
42 + 4n
Context
Switching
22
–
–
23
–
–
22
–
–
23
–
–
Remarks 1.
IROM: Internal ROM (with high-speed fetch specified)
PRAM: Peripheral RAM of internal RAM (only when LOCATION 0H instruction is executed in the
case of branch destination)
IRAM:
Internal high-speed RAM
EMEM: Internal ROM when external memory and high-speed fetch are not specified
n is the number of wait states per byte necessary for writing data to the stack (the number of wait
states is the sum of the number of address wait states and the number of access wait states).
It the vector table is EMEM, and if wait states are inserted in reading the vector table, add 2m to
the value of the vectored interrupt in the above table, and add m to the value of context switching,
where m is the number of wait states per byte necessary for reading the vector table.
It the branch destination is EMEM and if wait states are inserted in reading the instruction at the
branch destination, add that number of wait states.
If the stack is occupied by PRAM and if the value of the stack pointer (SP) is odd, add 4 to the value
in the above table.
The number of wait states is the sum of the number of address wait states and the number of access
wait states.
2.
3.
4.
5.
6.