274
Table 11.3 Buffered Input Capture Edge Selection (Example)
IEDGA
IEDGC
Description
0
Captured on falling edge of input capture A (FTIA)
(Initial value)
1
Captured on both rising and falling edges of input capture A (FTIA)
10
1
Captured on rising edge of input capture A (FTIA)
To ensure input capture, the width of the input capture pulse should be at least 1.5 system clock
periods (1.5). When triggering is enabled on both edges, the input capture pulse width should
be at least 2.5 system clock periods.
ICR is initialized to H'0000 by a reset and in hardware standby mode.
11.2.4
Output Compare Registers AR and AF (OCRAR, OCRAF)
Bit
Initial
15
1
R/W
14
1
R/W
13
1
R/W
12
1
R/W
11
1
R/W
10
1
R/W
9
1
R/W
8
1
R/W
7
1
R/W
6
1
R/W
5
1
R/W
4
1
R/W
3
1
R/W
2
1
R/W
1
R/W
0
1
R/W
value
Write
Read/
OCRAR and OCRAF are 16-bit readable/writable registers.
When the OCRAMS bit in TOCR is set to 1, the operation of OCRA is changed to include the
use of OCRAR and OCRAF. The contents of OCRAR and OCRAF are automatically added
alternately to OCRA, and the result is written to OCRA. The write operation is performed on the
occurrence of compare-match A. In the first compare-match A after the OCRAMS bit is set to 1,
OCRAF is added.
The operation due to compare-match A varies according to whether the compare-match follows
addition of OCRAR or OCRAF. The value of the OLVLA bit in TOCR is ignored, and 1 is
output on a compare-match A following addition of OCRAF, while 0 is output on a compare-
match A following addition of OCRAR.
When the OCRA automatically addition function is used, do not set internal clock /2 as the
FRC counter input clock together with an OCRAR (or OCRAF) value of H'0001 or less.
OCRAR and OCRAF are initialized to H'FFFF by a reset and in hardware standby mode.