///
/// Where **prescaler can be (1, 8, 64, 512)** and **TOP can be 0 to 65532**.
/// Modulated value is represented by 16 bits in process data and internally scaled to 0 to TOP range.
/// Because this leads to a bigger value of TOP and so a better resolution of the modulated value.
/// Prescaler Recommended range low boundary Recommended range high boundary
/// 8
100 Hz TOP = 40000 < 1 kHz TOP = 4000
/// 512
1 Hz TOP = 62500 < 10 Hz TOP = 6250
/// Example:
/// f_PWM = 10Hz => 16#C352 = 50002
/// base frequency of the PWM, anywhere from 1Hz to 100kHz (10 Hz = 10, 100kHz = 100000)
ePrescale : MNR.ePrescaler; /// Determined prefered prescaler
uiRangeLow : UINT;
uiRangeHigh : UINT;
uiTOP : UINT; /// Determined TOP setting
/// clip the input Hz on lower and upper bound;
_uidiHz := LIMIT( 1, udiHz, 100000);
//// Determine prescaler and TOP according to table
CASE _uidiHz OF
1..9 : ePrescale := ePrescaler.ScaleFactor512;
uiTOP := TO_UINT( (32000000/ 64/ _uidiHz)); // interpolate between 10 and 100Hz
100..999 : ePrescale := ePrescaler.ScaleFactor8;
uiTOP := TO_UINT( (32000000/ 1/ _uidiHz));// interpolate between 1000 and 100000Hz
END_CASE
/// Now set prescaler
/// bit 15 .. 2 : TOP / 4
CASE ePrescale OF
/// 00 0 : prescaler = 1
ePrescaler.ScaleFactor1 : fPWM.0 := FALSE;
fPWM.1 := FALSE;
/// 01 1 : prescaler = 8
ePrescaler.ScaleFactor8 : fPWM.0 := TRUE;
/// 10 2 : prescaler = 64
ePrescaler.ScaleFactor64 : fPWM.0 := FALSE;
fPWM.1 := TRUE;
/// 11 3 : prescaler = 512
ePrescaler.ScaleFactor512 : fPWM.0 := TRUE;
// 8.0 2.0 PWM1 frequency
THIS^._abyIntTxBuf[16] := WORD_TO_BYTE(fPWM);
THIS^._abyIntTxBuf[17] := WORD_TO_BYTE(SHR(fPWM,8));