Changing Interrupt Generate Factor; Int Interrupt - Renesas M16C/6NK Hardware Manual

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M16C/6N Group (M16C/6NK, M16C/6NM)

23.8.4 Changing Interrupt Generate Factor

If the interrupt generate factor is changed, the IR bit of the interrupt control register for the changed
interrupt may inadvertently be set to "1" (interrupt requested). If you changed the interrupt generate factor
for an interrupt that needs to be used, be sure to set the IR bit for that interrupt to "0" (interrupt not
requested).
Changing the interrupt generate factor referred to here means any act of changing the source, polarity or
timing of the interrupt assigned to each software interrupt number. Therefore, if a mode change of any
peripheral function involves changing the generate factor, polarity or timing of an interrupt, be sure to set
the IR bit for that interrupt to "0" (interrupt not requested) after making such changes. Refer to the description
of each peripheral function for details about the interrupts from peripheral functions.
Figure 23.3 shows the procedure for changing the interrupt generate factor.
IR bit: A bit in the interrupt control register for the interrupt whose interrupt
NOTES:
Figure 23.3 Procedure for Changing Interrupt Generate Factor
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23.8.5 INT Interrupt

• Either an "L" level of at least tW(INH) or an "H" level of at least tW(INL) width is necessary for the signal
________
input to pins INT0 to INT8
• If the POL bit in the INT0IC to INT8IC registers
IFSR23 to IFSR25 bits
(interrupt requested). Be sure to set the IR bit to "0" (interrupt not requested) after changing any of those
register bits.
NOTES:
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1. The pins INT6 to INT8 are only in the 128-pin version.
2. The INT6IC to INT8IC registers are only in the 128-pin version.
3. The IFSR23 to IFSR25 bits are effective only in the128-pin version. In the 100-pin version,
these bits are set to "0" (one edge).
Rev.2.00 Nov 28, 2005
REJ09B0124-0200
Changing the interrupt source
Disable interrupt
Change the interrupt
(including a mode change of peripheral function)
Use the MOV instruction to set the IR bit to "0"
(interrupt not requested)
Enable interrupt
to be changed
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 8; 6 to 8 are only in the 128-pin version).
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
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
to be changed.
3.Refer to 23.8.6 Rewrite Interrupt Control Register
use and the notes to be taken for instruction execution.
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(1)
regardless of the CPU operation clock.
(3)
in the IFSR2 register are changed, the IR bit may inadvertently set to "1"
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(2) (3)
generate factor
(3)
(2) (3)
End of change
generate factor. In this case, if the maskable
for details about the instructions to
(2)
, the IFSR10 to IFSR15 bits in the IFSR1 register or the
23. Usage Precaution
generate factor is
generate factor is