Hitachi H8S/2338 Series Hardware Manual page 304

Example of PWM Mode Setting Procedure: Figure 7-24 shows an example of the PWM mode
setting procedure.
PWM mode
Select counter clock
Select counter clearing source
Select waveform output level
Set TGR
Set PWM mode
Start count
<PWM mode>
Figure 7-24 Example of PWM Mode Setting Procedure
Examples of PWM Mode Operation: Figure 7-25 shows an example of PWM mode 1 operation.
In this example, TGRA compare match is set as the TCNT clearing source, 0 is set for the TGRA
initial output value and output value, and 1 is set as the TGRB output value.
In this case, the value set in TGRA is used as the period, and the value set in TGRB as the duty.
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[1] Select the counter clock with bits TPSC2 to
TPSC0 in TCR. At the same time, select the
input clock edge with bits CKEG1 and CKEG0 in
TCR.
[1]
[2] Use bits CCLR2 to CCLR0 in TCR to select the
TGR to be used as the TCNT clearing source.
[2]
[3] Use TIOR to designate the TGR as an output
compare register, and select the initial value and
output value.
[3]
[4] Set the period in the TGR selected in [2], and
set the duty in the other TGR.
[4]
[5] Select the PWM mode with bits MD3 to MD0 in
TMDR.
[5]
[6] Set the CST bit in TSTR to 1 to start the count
operation.
[6]