
Rev. 2.0, 09/02, page 239 of 732
Input Capture Function
The TCNT value can be transferred to TGR on detection of the TIOC pin input edge.
Rising edge, falling edge, or both edges can be selected as the detected edge. For channels 0 and 1,
it is also possible to specify another channel's counter input clock or compare match signal as the
input capture source.
Note:
When another channel's counter input clock is used as the input capture input for channels
0 and 1, P
φ
/1 should not be selected as the counter input clock used for input capture
input. Input capture will not be generated if P
φ
/1 is selected.
Example of Input Capture Operation Setting Procedure:
Figure 11.9 shows an example of the
input capture operation setting procedure.
Input selection
Select input capture input
Start count
<Input capture operation>
[1]
[2]
[1] Designate TGR as an input capture
register by means of TIOR, and select
rising edge, falling edge, or both edges
as the input capture source and input
signal edge.
[2] Set the CST bit in TSTR to 1 to start
the count operation.
Figure 11.9 Example of Input Capture Operation Setting Procedure
Example of Input Capture Operation:
Figure 11.10 shows an example of input capture
operation.
In this example both rising and falling edges have been selected as the TIOCA pin input capture
input edge, the falling edge has been selected as the TIOCB pin input capture input edge, and
counter clearing by TGRB input capture has been designated for TCNT.