Int0 Input Filter - Renesas M16C FAMILY Hardware Manual

Under development
Preliminary specification
Specifications in this manual are tentative and subject to change.
R8C/11 Group
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10.2.2 INT0 Input Filter

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The INT0 input has a digital filter which can be sampled by one of three sampling clocks. The sampling
clock is selected using the INT0F1 to INT0F0 bits in the INT0F register. The IR bit in the INT0IC
register is set to "1" (interrupt requested) when the sampled input level matches three times. When the
INT0F1 to INT0F0 bits are set to "01
filtered value.
Figure 10.11 shows the INT0 input filter configuration. Figure 10.12 shows an operation example of
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INT0 input filter.
f
f
f
INT0
Port P45
direction
register
INT0F0, INT0F1: Bits in INT0F register
INT0EN: Bit in INTEN register
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Figure 10.11 INT0 Input Filter
P45 input
Sampling
timing
P4_5 in
P4 register
IR bit in
INT0IC register
This is an operation example when the INT0F1 to INT0F0 bits in the
INT0F register is set to "01
Figure 10.12 Operation Example of INT0 Input Filter
Rev.0.91 2003 Sep 08
2
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INT0F1 to INT0F0
=01
2
1
Sampling clock
=10
2
8
=11
2
32
Digital filter
(input level
matches 3x)
", "01 ", or "01 " (passing digital filter).
2 2 2
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", "10 ", or "11 ", the P4_5 bit in the P4 register indicates the
2 2
INT0EN
Other than
INT0F1 to INT0F0
=00
2
=00
2
Set to "0" in program
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10.2 INT Interrupt
INT0 interrupt
P4_5 bit