Hitachi H8/3672 Series Hardware Manual page 160

TCNT value
H'FFFF
GRA
GRB
H'0000
FTIOA
FTIOB
Figure 11-5 Toggle Output Example (TOA = 0, TOB = 1)
Figure 11-6 shows another example of toggle output when TCNT operates as a periodic counter,
cleared by compare match A. Toggle output is selected for both compare match A and B.
TCNT value
H'FFFF
GRB
GRA
H'0000
FTIOA
FTIOB
Figure 11-6 Toggle Output Example (TOA = 0, TOB = 1)
The TCNT value can be captured into a general register (GRA, GRB, GRC, or GRD) when a
signal level changes at an input-capture pin (FTIOA, FTIOB, FTIOC, or FTIOD). Capture can
take place on the rising edge, falling edge, or both edges. By using the input-capture function, the
pulse width and periods can be measured. Figure 11-7 shows an example of input capture when
both edges of FTIOA and the falling edge of FTIOB are selected as capture edges. TCNT operates
as a free-running counter.
Rev. 1.0, 03/01, page 136 of 280
Counter cleared by compare match with GRA
Time
Toggle output
Toggle output
Time
Toggle
output
Toggle
output