R8C/18 Group, R8C/19 Group
12. Interrupts
Rev.1.30
Apr 14, 2006
Page 88 of 233
REJ09B0222-0130
12.2.4
INT3 Interrupt
The INT3 interrupt is generated by an INT3 input. Set the TCC07 bit in the TCC0 register to 0 (INT3).
When the TCC06 bit in the TCC0 register is set to 0, an INT3 interrupt request is generated in
synchronization with the count source of timer C. If the TCC06 bit is set to 1, the INT3 interrupt
request is generated when an INT3 input occurs.
The INT3 input contains a digital filter. The INT3 level is sampled every sampling clock cycle and if
the sampled input level matches three times, the IR bit in the INT3IC register is set to 1 (interrupt
requested). The sampling clock is selected by bits TCC11 to TCC10 in the TCC1 register. If filter is
selected, the interrupt request is generated in synchronization with the sampling clock, even if the
TCC06 bit is set to 1. The P3_3 bit in the P3 register indicates the value before filtering regardless of
the contents set in bits TCC11 to TCC10.
The INT3 pin is used with the TCIN pin.
If the TCC07 bit is set to 1 (fRING128), the INT3 interrupt is generated by the fRING128 clock. The
IR bit in the INT3IC register is set to 1 (interrupt requested) every fRING128 clock cycle or every half
fRING128 clock cycle.
Figure 12.15 shows the TCC0 Register and Figure 12.16 shows the TCC1 Register.
Figure 12.15
TCC0 Register
Timer C Control Register 0
Symbol
Address
After Reset
TCC0
009Ah
00h
Bit Symbol
Bit Name
Function
RW
INT3
_____
interrupt and capture
polarity select bits
(1, 2)
Set to 0.
INT3
_____
interrupt request
0 : INT3
_____
interrupt is generated in
generation timing select
synchronization w ith timer C count source.
bit
(2, 3)
1 : INT3
_____
interrupt is generated w hen
INT3
_____
interrupt is input.
(4)
INT3
_____
interrupt and capture
0 : INT3
_____
input sw itch bit
(1, 2)
1 : fRING128
NOTES:
1.
2.
3.
4.
The IR bit in the INT3IC register may be set to 1 (requests interrupt) w hen the TCC03, TCC04, TCC06, or TCC07 bit is
rew ritten. Refer to
12.5.5 Changing Interrupt Sources
.
b4 b3
0 0 : Rising edge
0 1 : Falling edge
1 0 : Both edges
1 1 : Do not set.
—
(b5)
Reserved bit
RW
b3 b2
RW
TCC04
RW
TCC03
Timer C count start bit
0 : Stops counting.
1 : Starts counting.
Timer C count source select
bits
(1)
b2 b1
0 0 : f1
0 1 : f8
1 0 : f32
1 1 : fRING-fast
b7 b6 b5 b4
b1 b0
0
TCC00
RW
TCC01
RW
When the TCC13 bit is set to 1 (output compare mode) and an INT3
_____
interrupt is input, regardless of the setting
When using the INT3
_____
filter, the INT3
_____
interrupt is generated in synchronization w ith the clock for the digital filter.
value of the TCC06 bit, an interrupt request is generated.
TCC02
RW
TCC07
RW
TCC06
RW
Change this bit w hen the TCC00 bit is set to 0 (count stops).