3.4.2 Notes on Rewriting Port Mode Registers
When a port mode register is rewritten to switch the functions of external interrupt pins, the
following points should be observed.
When an external interrupt pin function is switched by rewriting the port mode register that controls
pins
IRQ
4
to
IRQ
0
,
WKP
7
to
WKP
0
, the interrupt request flag may be set to 1 at the time the pin
function is switched, even if no valid interrupt is input at the pin. Be sure to clear the interrupt
request flag to 0 after switching pin functions. Table 3-5 shows the conditions under which
interrupt request flags are set to 1 in this way.
Table 3-5 Conditions under which Interrupt Request Flag is Set to 1
Interrupt Request
Flags Set to 1
Conditions
IRR1
IRRI4
When PMR1 bit IRQ4 is changed from 0 to 1 while pin
IRQ
4
is low and IEGR
bit IEG4 = 0.
When PMR1 bit IRQ4 is changed from 1 to 0 while pin
IRQ
4
is low and IEGR
bit IEG4 = 1.
IRRI3
When PMR1 bit IRQ3 is changed from 0 to 1 while pin
IRQ
3
is low and IEGR
bit IEG3 = 0.
When PMR1 bit IRQ3 is changed from 1 to 0 while pin
IRQ
3
is low and IEGR
bit IEG3 = 1.
IRRI2
When PMR1 bit IRQ2 is changed from 0 to 1 while pin
IRQ
2
is low and IEGR
bit IEG2 = 0.
When PMR1 bit IRQ2 is changed from 1 to 0 while pin
IRQ
2
is low and IEGR
bit IEG2 = 1.
IRRI1
When PMR1 bit IRQ1 is changed from 0 to 1 while pin
IRQ
1
is low and IEGR
bit IEG1 = 0.
When PMR1 bit IRQ1 is changed from 1 to 0 while pin
IRQ
1
is low and IEGR
bit IEG1 = 1.
IRRI0
When PMR3 bit IRQ0 is changed from 0 to 1 while pin
IRQ
0
is low and IEGR
bit IEG0 = 0.
When PMR3 bit IRQ0 is changed from 1 to 0 while pin
IRQ
0
is low and IEGR
bit IEG0 = 1.
IWPR
IWPF7
When PMR5 bit WKP7 is changed from 0 to 1 while pin
WKP
7
is low.
IWPF6
When PMR5 bit WKP6 is changed from 0 to 1 while pin
WKP
6
is low.
IWPF5
When PMR5 bit WKP5 is changed from 0 to 1 while pin
WKP
5
is low.
IWPF4
When PMR5 bit WKP4 is changed from 0 to 1 while pin
WKP
4
is low.
IWPF3
When PMR5 bit WKP3 is changed from 0 to 1 while pin
WKP
3
is low.
IWPF2
When PMR5 bit WKP2 is changed from 0 to 1 while pin
WKP
2
is low.
IWPF1
When PMR5 bit WKP1 is changed from 0 to 1 while pin
WKP
1
is low.
IWPF0
When PMR5 bit WKP0 is changed from 0 to 1 while pin
WKP
0
is low.
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