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Selection of count clock
The 8/16-bit PPG timer uses the input from the peripheral clock and timebase counter as a
counter clock, allowing a selection from six types of count clock input.
Bit4 to bit2 of the PPG01/PPG23/PPG45 registers (PCM2 to 0) are used to select the clock of
channel 0 (channel 2 or channel 4), and bit7 to bit5 of the PPG01/PPG23/PPG45 registers
(PCS2 to PCS0) are used to select the clock of channel 1 (channel 3, or channel5).
The clock is selected from among the machine clock (multiplied by 1/16 to 1) or the timebase
counter.
Notes:
• In 8-bit prescaler/8-bit PPG mode and in 16-bit PPG mode, the value in bit14 of the PPGC1
register (PCS1) is invalid.
• If the input from timebase timer is used, the first count cycle after a trigger or stop event may be
out of sync. If the timebase counter is initialized while the 8/16-bit PPG timer is running, cycles
may be out of sync.
• If, in 8-bit prescaler/8-bit PPG mode, channel 0/2/4 is in active mode and channel 1/3/5 is in
stopped mode, the first count cycle may be out of sync when operation of channel 1 (channel 3
or channel 5) starts.
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Pin output control of pulses
Pulses generated by the 8/16-bit PPG timer output from the external pins (PPG0 to PPG5). To
output pulses from an external pin, set the bit corresponding to the pin to "1". For enabling
PPG0/PPG2/PPG4 pin output, bit5 of PPGC0 (PE0) is used, and for enabling PPG1/PPG3/
PPG5 pin output, bit3 of PPGC1 (PE1) is used. If the respective bit is set to "0" (initial value),
the external pin does not output pulses, but is used as a general-purpose port.
In 16-bit PPG mode, PPG0 to PPG5 output the same waveform. For this reason, it is sufficient
to enable pin output for either of the corresponding pins to obtain the same output.
In 8-bit prescaler + 8-bit PPG mode, PPG0/PPG2/PPG4 output a toggle waveform of the 8- bit
prescaler, and PPG1/PPG3/PPG5 output a waveform of 8-bit PPG.
Output waveform in this mode is illustrated in Figure 15.5-2.
CHAPTER 15 8/16-BIT PPG TIMER
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