W79E225A_08 Datasheet, PDF (124/203 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E225A/226A/227A Data Sheet
Example Steps of setting up Single Shot:-
1. Set initial state = 0 (controlled by EPOL option bit)
2. PWM0EN=0, POVM.0=0, PWM0I=0, PWM0=0000H(for keep comparator output in low state),
PWMP=0001H(let the period as short as possible)
3. PWMRUN=1(Do a dummy PWMRUN for loading PWM0 to compare register0, which make
comparator output LOW always.
4. PWM0EN=1, now the PWM0 pin should be still in 0 state.
5. PWMP=xxxxH(controls a period), PWM0=yyyyH(controls duty or pulse width)
 PWMRUN=1(this time a real PWM single shot signal user wanted. The wave form should be the
upper one.

Note: In single shot mode, it’s important that user sets CLRPWM together with PWMRUN and
LOAD in order to have PWMn and PWMP loaded into working registers immediately.
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Publication Release Date: April 15, 2008
Revision A4.0