Explanation Of 16-Bit Ppg Timer Operations And Setup Procedure Example - Fujitsu F2MC-8FX Hardware Manual

17.7 Explanation of 16-bit PPG Timer Operations and Setup
Procedure Example
The 16-bit PPG timer can operate in PWM mode or one-shot mode. In addition, a
retrigger function can be used in the 16-bit PPG timer.
PWM Mode (MDSE of PCNTH Register: bit 5 = 0)
In PWM operation mode, the 16-bit PPG cycle setting buffer register (PCSRH0, PCSRL0) values are
loaded and the 16-bit down-counter starts down-count operation when a software trigger is inputted or a
hardware trigger by TRG pin input is inputted. When the count value reaches "1", the 16-bit PPG cycle
setting buffer register (PCSRH0, PCSRL0) values are reloaded to repeat the down-count operation.
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" synchronizing with count clock. The output changes back
to "L" when the "H" was output until the value of duty setting. (The output levels will be reversed if OSEL
is set to "1".)
When the retrigger function is disabled (RTRG = 0), software triggers (STRG = 1) are ignored during the
operation of the down-counter.
When the down-counter is not running, the maximum time between a valid trigger input occurring and the
down-counter starting is as follows.
Software trigger: 1count clock cycle + 2 machine clock cycles
Hardware trigger by TRG Pin input: 1 count clock cycle + 3 machine clock cycles
The minimum time is as follows.
Software trigger: 2 machine clock cycles
Hardware trigger by TRG Pin input: 3 machine clock cycles
When the down-counter is running, the maximum time between a valid retrigger input occurring and the
down-counter restarting is as follows.
Software trigger: 1 count clock cycle + 2 machine clock cycles
Hardware trigger by TRG Pin input: 1 count clock cycle + 3 machine clock cycles
The minimum time is as follows.
Software trigger: 2 machine clock cycles
Hardware trigger by TRG Pin input: 3 machine clock cycles
CHAPTER 17 16-BIT PPG TIMER
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