M16C28 Datasheet, PDF (377/423 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/28 Group (M16C/28, M16C/28B)
20. Precautions
Changing the interrupt source
Disable interrupts ^(2,3)
Change the interrupt generate factor (including a mode change of peripheral function)
Use the MOV instruction to clear the IR bit to “0” (interrupt not requested) ⁽³⁾
Enable interrupts ^(2,3)
End of change
IR bit: A bit in the interrupt control register for the interrupt whose interrupt generate factor is to
be changed
NOTES:
1.The above settings must be executed individually. Do not execute two or more settings
simultaneously (using one instruction).
2. Use the I flag for the INTi interrupt (i = 0 to 5).
For the interrupts from peripheral functions other than the INTi interrupt, turn off the
peripheral function that is the source of the interrupt in order not to generate an interrupt
request before changing the interrupt generate factor. In this case, if the maskable interrupts
can all be disabled without causing a problem, use the I flag. Otherwise, use the corresponding
ILVL2 to ILVL0 bit for the interrupt whose interrupt generate factor is to be changed.
3. Refer to 20.5.6 Rewrite the Interrupt Control Register for details about the
instructions to use and the notes to be taken for instruction execution.
Figure 20.3 Procedure for Changing the Interrupt Generate Factor
______
20.4.5 INT Interrupt
1. Either an “L” level of at least tW(INL) or an “H” level of at least tW(INH) width is necessary for the signal
________
________
input to pins INT0 through INT5 regardless of the CPU operation clock.
2. If the POL bit in the INT0IC to INT5IC registers or the IFSR7 to IFSR0 bits in the IFSR register are
changed, the IR bit may inadvertently set to 1 (interrupt requested). Be sure to clear the IR bit to 0
(interrupt not requested) after changing any of those register bits.
_______
3. When using the INT5 interrupt for exiting stop mode, set the P17DDR register to “FF16” (disable digital
debounce filter) before entering stop mode.
Rev. 2.00 Jan. 31, 2007 ^{page 357} of 385
REJ09B0047-0200