Rev.3.04
May 20, 2008
REJ03B0158-0304
38D5 Group
<Notes>
The interrupt request bit may be set to “1” in the following cases.
When setting the external interrupt active edge
Related bits: INT0 interrupt edge selection bit
(bit 0 of interrupt edge selection register
(address 003A16))
INT1 interrupt edge selection bit
(bit 1 of interrupt edge selection register)
INT2 interrupt edge selection bit
(bit 2 of interrupt edge selection register)
CNTR0 activate edge switch bit
(bits 6 and 7 of timer X control register 1
(address 002E16))
CNTR1 activate edge switch bit
(bits 6 of timer Y mode register
(address 003816))
When switching the interrupt sources of an interrupt vector
address where two or more interrupt sources are assigned
Related bit:
Timer Y/CNTR1 interrupt switch bit
(bit 3 of interrupt edge selection register)
When switching the INT pins
Related bits: INT0 input port switch bit
(bit 4 of interrupt edge selection register)
INT1 input port switch bit
(bit 5 of interrupt edge selection register)
If it is not necessary to generate an interrupt synchronized with
these settings, take the following sequence.
(1) Set the corresponding enable bit to “0” (disabled).
(2) Set the interrupt edge selection bit (the active edge switch
bit) or the interrupt source bit.
(3) Set the corresponding interrupt request bit to “0” after one
or more instructions have been executed.
(4) Set the corresponding interrupt enable bit to “1” (enabled).
Fig. 22 Timing of interrupt request generation, interrupt request bit, and interrupt acceptance
T1
(1) The interrupt request bit for an interrupt request generated during period 1 is set to “1” at timing point IR1.
(2) The interrupt request bit for an interrupt request generated during period 2 is set to “1” at timing point IR1 or IR2.
The timing point at which the bit is set to “1” varies depending on conditions. When two or more interrupt
requests are generated during the period 2, each request bit may be set to “1” at timing point IR1 or IR2
separately.
T1 T2 T3 : Interrupt acceptance timing points
IR1 IR2 : Timings points at which the interrupt request bit is set to “1”.
Note : Period 2 indicates the last
φ cycle during one instruction cycle.
IR1 T2
SYNC
IR2 T3
12
Internal clock
φ
Instruction cycle
Push onto stack
Vector fetch
Instruction cycle