How to use the GTM ATOM PWM Driver

Collaboration diagram for How to use the GTM ATOM PWM Driver:

This interface allows to generate simple PWM signal on a ATOM out put and can generate interrupts if enabled. this output can also be routed to port pin if required.

Preparation

Include Files

Include following header file into your C code:

#include <Gtm/Atom/Pwm/IfxGtm_Atom_Pwm.h>

Variables

define global variables if necessary

Ifx_GTM *gtm = &MODULE_GTM;
#define ATOM0_CH0_PRIO 20

Interrupts

define Interrupts if needed

IFX_INTERRUPT(ATOM0Ch0_ISR, 0, ATOM0_CH0_PRIO)
{}

Initialization

// install interrupt handlers
IfxCpu_Irq_installInterruptHandler (ATOM0Ch0_ISR, ATOM0_CH0_PRIO);

// enable GTM clock
{
    float32 frequency = IfxGtm_Cmu_getModuleFrequency(gtm);
    // Enables the GTM
    IfxGtm_enable(gtm);
    // Set the global clock frequency to the max
    IfxGtm_Cmu_setGclkFrequency(gtm, frequency);
    // Set the CMU CLK0
    IfxGtm_Cmu_setClkFrequency(gtm, IfxGtm_Cmu_Clk_0, frequency);
    // FXCLK: used by TOM and CLK0: used by ATOM
    IfxGtm_Cmu_enableClocks(gtm, IFXGTM_CMU_CLKEN_FXCLK | IFXGTM_CMU_CLKEN_CLK0);
}

// initialise ATOM
IfxGtm_Atom_Pwm_Config atomConfig;  \\configuration structure
IfxGtm_Atom_Pwm_Driver atomHandle;  \\ handle

IfxGtm_Atom_Pwm_initConfig(&atomConfig, gtm);

atomConfig.tomChannel  = IfxGtm_Tom_Ch_0;
atomConfig.period                   = 20;
atomConfig.dutyCycle              = 10;
atomConfig.interrupt.ccu0Enabled = TRUE;
atomConfig.interrupt.isrPriority = ATOM0_CH0_PRIO;
atomConfig.pin.outputPin = &IfxGtm_ATOM0_0_TOUT0_P02_0_OUT;

IfxGtm_Atom_Pwm_init(&atomHandle, &atomConfig);

ATOM will be now generating a PWM signal on the selected port pin while generating selected interrupt according to above configured period and duty cycle.