Changing The Interrupt Generate Factor; Int Interrupt - Renesas M16C/60 Series Hardware Manual

Under development
This document is under development and its contents are subject to change.
M16C/6N5 Group

1.5.4 Changing the Interrupt Generate Factor

If the interrupt generate factor is changed, the IR bit in 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, polar-
ity 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 1.5.1 shows the procedure for changing the interrupt generate factor.
R bit: A bit in the interrupt control register for the interrupt whose interrupt
be changed
Note 1: The above settings must be executed individually. Do not execute two or more settings
simultaneously (using one instruction).
Note 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
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
Note 3: Refer to
and the notes to be taken for instruction execution.
Figure 1.5.1 Procedure for Changing Interrupt Generate Factor
_____

1.5.5 INT Interrupt

1. Either an "L" level of at least t
input to pins INT
2. If the POL bit in the INT0IC to INT5IC registers or the IFSR17 to IFSR10 bits in the IFSR1 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.
Rev.1.00 2003.05.30 page 6
Changing the interrupt source
Disable interrupts (Notes 2, 3)
Change the interrupt
(including a mode change of peripheral function)
Use the MOV instruction to set the IR bit to "0"
(interrupt not requested) (Note 3)
Enable interrupts (Notes 2, 3)
"Rewrite the Interrupt Control
or an "H" level of at least t
W(INH)
_______ _______
through INT regardless of the CPU operation clock.
0 5
generate factor
End of change
generate factor. In this case, if the maskable
generate factor
Register" for details about the instructions to use
W(INL)
1.5 Precautions for Interrupts
generate factor is to
is to be changed.
width is necessary for the signal