HPWM 16 Bit

Syntax:

    HPWM16 channel, frequency, duty cycle    'Enable a 16-bit PWM channel'

    HPWM16On channel                         'Enable a specific PWM channel using parameters set by the HPWM16 method'

    HPWM16Off channel                        'Disable a specific PWM channel'

Command Availability:

Only available on Microchip PIC microcontrollers with the 16-bit PWM module. 16-bit PWM support includes both dynamic mode and fixed mode operations. See the examples below for usage.

The PIC microcontroller chip specific DAT file must contain CHIPPWM16TYPE = 1.   If the chip specific DAT does not contain CHIPPWM16TYPE = 1 and the microcontroller does support PWM 16 Bit please report the omission to GCBASIC the support forum.  

For the Capture/Compare/PWM (CCP) module or the 10-bit PWM module, see the other sections of the Help.

Explanation:

This command sets up the hardware PWM module of the Microchip PIC microcontroller to generate a PWM waveform of the given frequency and duty cycle. Once this command is called, the PWM will be emitted until HPWM16Off method is called.

channel is 1, 2, 3.. 12. These corresponds to the 16-bit PWM channel respectively.
The 16-bit PWM channel MUST be supported by the microcontroller. Check the microcontroller specific datasheet for the available channel.

frequency sets the frequency of the PWM output. It is measured in KHz. The maximum value allowed is 0xFFFF. The minimum value varies depending on the clock speed. 1 KHz is the minimum on chips 16 MHz or under and 2 Khz is the lowest possible on 20 MHz chips. In situations that do not require a specific PWM frequency, the PWM frequency should equal approximately 1 five-hundredth the clock speed of the microcontroller (ie 40 Khz on a 20 MHz chip, 16 KHz on an 8 MHz chip). This gives the best duty cycle resolution possible.

duty cycle specifies the desired duty cycle of the PWM signal, and ranges from 0 to 0xFFFF where 0xFFFF is 100% duty cycle.    This should be a WORD value.



Example 1:

    ' This program will enable dynamic mode PWM signals
    '
    ' All the 12 PWM16 channels can configured at separate dynamic frequencies  dynamic duty, the syntax is:
    '
    ' HPWM16(xx, frequency, duty )
    '
    ' xx can be 1 through 12, for this specific microcontroller there are three PWM16 channels.
    '
    ' To set the parameters of GCBASIC PWM fixed mode for the channels use the commands shown below::

        #chip 12F1572, 32
        #config mclr=on

        Dir PORTA Out

        HPWM16(1, 30, 16384)   '30 kHz, 25% duty cycle (16384/65535)
        HPWM16(2, 30, 16384)   '30 kHz, 25% duty cycle (16384/65535)
        HPWM16(3, 30, 16384)   '30 kHz, 25% duty cycle (16384/65535)


        do Forever
        loop


        #define USE_HPWM16_1 TRUE
        #define USE_HPWM16_2 TRUE
        #define USE_HPWM16_3 TRUE
        #define USE_HPWM16_4 FALSE
        #define USE_HPWM16_5 FALSE
        #define USE_HPWM16_6 FALSE
        #define USE_HPWM16_7 FALSE
        #define USE_HPWM16_8 FALSE
        #define USE_HPWM16_9 FALSE
        #define USE_HPWM16_10 FALSE
        #define USE_HPWM16_11 FALSE
        #define USE_HPWM16_12 FALSE



The 16-bit library also supports fixed mode PWM operations. The following two examples show the constants and the commands to control 16-bit PWM Fixed Mode operations.

Example 2:

    ' This program will enable fix mode PWM signals
    '
    ' All the 12 PWM16 channels can configured at separate fixed frequencies and fixed duty, the syntax is:
    '
    ' #define HPWM16_xx_Freq 38     'Set frequency in KHz on channel xx
    ' #define HPWM16_xx_Duty 50     'Set duty cycle to 50%  on channel xx
    '
    ' xx can be 1 through 12
    '
    ' To set the parameters of GCBASIC PWM fixed mode on channel 1 use the following:
    '
    '    #define HPWM16_1_Freq 0.1 to > 1000         'Set the frequency, but, the clock speed must be low for low PWM frequency
    '    #define HPWM16_1_Duty 0.1 to 100            'Set duty cycle as percentage 0-100%, just change the number
    '


        #chip 12F1572, 32
        #config mclr=on

        Dir PORTA Out

        #define HPWM16_1_Freq 400         '800Hz to greater than 1mhz... greater than 1mhz at a clock speed of 32hz provides a clipped square wave.
        #define HPWM16_1_Duty 50
        HPWM16On ( 1 )

        do Forever
        loop



Example 3:

    ' This program will enable fix mode PWM signals
    '
    ' All the 12 PWM16 channels can configured at separate fixed frequencies and fixed duty, the syntax is:
    '
    ' #define HPWM16_xx_Freq 38     'Set frequency in KHz on channel xx
    ' #define HPWM16_xx_Duty 50     'Set duty cycle to 50%  on channel xx
    '
    ' xx can be 1 through 12, for this specific microcontroller there are three PWM16 channels.
    '
    ' To set the parameters of GCBASIC PWM fixed mode for the three channels use the following:

        #chip 12F1572, 32
        #config mclr=on

        Dir PORTA Out

        #define HPWM16_1_Freq 100         '100khz
        #define HPWM16_1_Duty 40          '40% duty
        HPWM16On ( 1 )

        #define HPWM16_2_Freq 200         '200khz
        #define HPWM16_2_Duty 50          '50% duty
        HPWM16On ( 2 )

        #define HPWM16_3_Freq 300         '300khz
        #define HPWM16_3_Duty 60          '60% duty
        HPWM16On ( 3 )

        do Forever
        loop

For more help, see PWMOff

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