Datasheet

Section 13 Timer RC
Rev. 1.50 Sep. 18, 2007 Page 241 of 584
REJ09B0240-0150
The TRCCNT value can be captured into a general register (GRA, GRB, GRC, or GRD) when
signal levels are changed on an input-capture pin (FTIOA, FTIOB, FTIOC, or FTIOD) by
specifying the general register as an input capture register. The capture timing can be selected
from the rising, falling, or both edges. By using the input-capture function, the width or cycle of a
pulse can be measured. Figure 13.7 shows an example of an input capture when both edges of the
FTIOA signal and the falling edge of the FTIOB signal are selected as capture timings. TRCCNT
functions as a free-running counter.
TRCCNT
H'FFFF
H'1000
H'0000
FTIOA
GRA
Time
H'AA55
H'55AA
H'F000
H'1000 H'F000 H'55AA
GRB
H'AA55
FTIOB
Figure 13.7 Input Capture Operating Example