8-Bit Pwm Operation - Renesas Hitachi H8S/2194 Series Hardware Manual

19.3

8-Bit PWM Operation

The 8-bit PWM outputs PWM pulses having a cycle length of 256 states and a pulse width
determined by the data registers (PWR).
The output PWM pulse can be converted to a DC voltage through integration in a low-pass filter.
Figure 19.2 shows the output waveform example of 8-bit PWM. The pulse width (Twidth) can
be obtained by the following expression:
Twidth = (1/φ) × (PWR setting value)
FRC lower H'FF
8-bit value
PWRn setting
value
H'00
PWRn pin (Positive
output polarity)
(n=3 to 0)
(Negative
polarity)
Figure 19.2 8-bit PWM Output Waveform (Example)
Pulse width
T width
T width
Pulse cycle
(256 states)
Pulse width
T width
T width
Pulse cycle
(256 states)
Rev. 2.0, 11/00, page 411 of 1037