Hitachi F-ZTAT H8/3039 Series Hardware Manual page 254

Example of Reset-Synchronized PWM Mode: Figure 8-32 shows an example of operation in
reset-synchronized PWM mode. TCNT3 operates as an up-counter in this mode. TCNT4 operates
independently, detached from GRA4 and GRB4. When TCNT3 matches GRA3, TCNT3 is cleared
and resumes counting from H'0000. The PWM outputs toggle at compare match with GRB3,
GRA4, GRB4, and TCNT3 respectively, and when the counter is cleared.
TCNT3 value
GRA3
GRB3
GRA4
GRB4
H'0000
TIOCA
3
TIOCB
3
TIOCA
4
TOCXA
4
TIOCB
4
TOCXB
4
Figure 8-32 Operation in Reset-Synchronized PWM Mode (Example)
For the settings and operation when reset-synchronized PWM mode and buffer mode are both
selected, see section 8.4.8, Buffering.
244
Counter cleared at compare match with GRA3
(when OLS3 = OLS4 = 1)
Time