PWMTimerTiva.h File Reference

Detailed Description

PWM driver implementation using Tiva General Purpose Timers.

============================================================================

The PWM header file should be included in an application as follows:

#include <ti/drivers/PWM.h>
#include <ti/drivers/pwm/PWMTimerTiva.h>

Refer to PWM.h for a complete description of APIs & example of use.

Operation

This driver configures a Tiva General Purpose Timer (GPT) in PWM mode. When in PWM mode, each GPT is divided into 2 PWM outputs. This driver manages each output as an independent PWM instance. The timer is automatically configured in count-down mode using the system clock as the source.

The timers operate at the system clock frequency (80 MHz or 120 MHz). So each timer tick is 12.5 ns or 8.3 ns respectively. The period and duty registers are 16 bits wide; thus 8-bit prescalars are used to extend period and duty registers. The maximum value supported is 16777215 ((2^24) - 1) timer counts; 209715 microseconds @ 80 MHz or 139810 microseconds @ 120 MHz. Updates to a PWM's period or duty will occur instantaneously (GPT peripherals do not have shadow registers).

---

#include <stdbool.h>
#include <ti/drivers/PWM.h>

Include dependency graph for PWMTimerTiva.h:

Go to the source code of this file.

Data Structures
struct	PWMTimerTiva_HWAttrsV1
	PWMTimerTiva Hardware attributes. More...
struct	PWMTimerTiva_Object
	PWMTimerTiva Object. More...

Typedefs
typedef struct PWMTimerTiva_HWAttrsV1	PWMTimerTiva_HWAttrsV1
	PWMTimerTiva Hardware attributes. More...
typedef struct PWMTimerTiva_Object	PWMTimerTiva_Object
	PWMTimerTiva Object. More...

Variables
const PWM_FxnTable	PWMTimerTiva_fxnTable

Typedef Documentation

typedef struct PWMTimerTiva_HWAttrsV1 PWMTimerTiva_HWAttrsV1

PWMTimerTiva Hardware attributes.

These fields are used by driverlib APIs and therefore must be populated by driverlib macro definitions. For TivaWare these definitions are found in:

• inc/hw_memmap.h
• driverlib/gpio.h
• driverlib/pin_map.h
• driverlib/timer.h

A sample structure is shown below:

const PWMTimerTiva_HWAttrsV1 pwmTivaHWAttrs[] = {
    {
        .timerBaseAddr = TIMER2_BASE,
            .halfTimer = TIMER_A,
        .pinTimerPwmMode = GPIO_PA4_T2CCP0,
        .gpioBaseAddr = GPIO_PORTA_BASE,
        .gpioPinIndex = GPIO_PIN_4
    }
};

typedef struct PWMTimerTiva_Object PWMTimerTiva_Object

PWMTimerTiva Object.

The application must not access any member variables of this structure!

Variable Documentation

const PWM_FxnTable PWMTimerTiva_fxnTable