User guide

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SmartBook for Renesas R8C/Tiny Microcontrollers
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match functions of the RD timer. Each of the compare registers has its own port
lines which changes the state when the contents of that particular register matches
with the timer’s counting register, TRDi.
Normally, compare match values meant for the active level of the PWM signals
are loaded into these registers. TRDGRA1 determines the period of the PWM
waveform in general. Then the timer counter TRDi is kept initialized to zero. The
timer RD is triggered to start counting by a software command.
Initially all the PWM signal lines are kept at the inactive level, either zero or one
level, as per individual initialization defined in the program. When any of these
compare registers matches its contents with the contents of TRDi, the corre-
sponding port line changes its state to the active level and stays in that level till
the contents of TRDi matches the PWM period data stored in the register,
TRDGRAi. Then the timer gets initialized to zero and the counting starts again to
generate the next set of PWM signals. The PWM signals are available at all port
lines pertaining to all compare registers except TRDRAi.
When these two timers are synchronously combined, up to six PWM waveforms
are available at the port lines.