One-shot Mode (MDSE of PCNTH0 Register: bit 5 = 1)
One-shot operation mode can be used to output a single pulse with a specified width when a valid trigger
input occurs. When retriggering is enabled and a valid trigger is detected during the counter operation, the
down counter value is reloaded.
The initial state of the PPG output is "L". When the 16-bit down-counter value matches the value set in the
duty setting registers, the output changes to "H". The output changes back to "L" when the counter reaches
"1". (The output levels will be reversed if OSEL is set to "1".)
Invalidating the retrigger (RTRG of PCNTH0 register: bit 4 = 0)
Figure 17.7-3 When Retrigger Is Invalid in One-shot Mode
Counter value
m
n
0
Software trigger
PPG
(Normal polarity)
PPG
(Inverted polarity)
Validating the retrigger (RTRG of PCNTH0 register: bit 4 = 1)
Counter value
m
n
0
Software trigger
PPG
(Normal polarity)
PPG
(Inverted polarity)
Rising edge detected
(1)
(2)
(1)=n × T ns
(2)=m × T ns
Figure 17.7-4 When Retrigger Is Valid in One-shot Mode
Rising edge detected
(1)=n × T ns
(2)=m × T ns
Trigger ignored
T : Count clock cycle
m: PCSRH0 & PCSRL0 register value
n : PDUTH0 & PDUTL0 register value
Trigger restarted
(1)
(2)
T : Count clock cycle
m: PCSRH0 & PCSRL0 register value
n : PDUTH0 & PDUTL0 register value
CHAPTER 17 16-BIT PPG TIMER
Time
Time
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