Fujitsu F2MC-8FX Hardware Manual page 310

CHAPTER 17 16-BIT PPG TIMER
Hardware Trigger
"Hardware trigger" refers to PPG activation by signal input to the TRG input pin. When EGS1 and EGS0
are set to "11" and the hardware trigger is used with TRG input, PPG starts operation on a rising edge and
halts the operation upon the detection of a falling edge.
Moreover, the PPG timer begins operation of the following rising edge from the beginning.
The operation can be retriggered by a valid TRG input hardware trigger regardless of the retrigger setting
of the RTRG bit when the TRG input hardware trigger has been selected.
Counter value
m
n
0
Hardware trigger
PPG
(Normal polarity)
(Inverted polarity)
Setup Procedure Example
The 16-bit PPG timer is set up in the following procedure:
Initial setup
1) Set the interrupt level (ILR5)
2) Enable the hardware trigger and interrupts, select the interrupt type, and enable output (PCNTL)
3) Select the count clock and the mode, and enable timer operation (PCNTH)
4) Set the cycle (PCSR)
5) Set the duty (PDUT)
6) Start the PPG by the software trigger (PCNTH:STGR = 1)
Interrupt processing
1) Process any interrupt
2) Clear the interrupt request flag (PCNTL:IRQF)
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Figure 17.7-5 Hardware Trigger in PWM Mode
Rising edge detected
(1)
(2)
(1)=n × T ns
(2)=m × T ns
Falling edge detected
T : Count clock cycle
m: PCSRH0 & PCSRL0 register value
n : PDUTH0 & PDUTL0 register value
Time