HD64F2149 Datasheet, PDF (386/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

12.3.6 Input Capture Operation
TMRX has input capture registers of TICR, TICRR and TICRF.
Narrow pulse width can be measured with TICRR and TICRF, using capture operation controlled
by the ICST bit in the TCONRI register of the timer connection.
When TMRIX detects rising edge and falling edge successively after the ICST bit is set to 1, the
value of TCNT at the time is transferred to TICRR and TICRF, respectively.
Input signal to TMRIX can be switched by the setting of the other bits in TCONRI register.
(1) Input capture signal input timing
Timing of the input capture operation is shown in figure 12.9.
φ
TMRIX
Input capture
signal
TCNTX
n
n+1
N
N+1
TICRR
M
n
n
TICRF
m
m
N
Figure12.9 Timing of Input Capture Operation
If input capture signal is input while TICRR and TICRF is read, the input capture signal delays by
one system clock (φ) period internally. Figure 12.10 shows the timing of this operation.
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