PWM not appearing on some pins [Tiva C Launchpad]

PF0 is locked by default in GPIO only NMI pin, check Table 10-1. GPIO Pins With Special Considerations on the datasheet. You need to unlock it

  //
  // Unlock the Pin PF0 and Set the Commit Bit
  //
  HWREG(GPIO_PORTF_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY;
  HWREG(GPIO_PORTF_BASE + GPIO_O_CR)   |= 0x01;

Also you have:

PWMPulseWidthSet(PWM1_BASE, PWM_OUT_1,pwmNow);

When it should be PWM_OUT_2

Thank you all for your help figuring this out.

Also you have:

PWMPulseWidthSet(PWM1_BASE, PWM_OUT_1,pwmNow);

When it should be PWM_OUT_2

The above suggestion fixed my issues with PA6. I suspected some type of "gotcha" with PF0 so I tried a different pin and port in PA6 only to be greeted by my own mistake :-P

The unlocking issue is perplexing. It would be nice if TI did something like using red-fill on the lock pins in every table where they are displayed (like table 20-1).

At any rate. I cleaned up my code and comments in hopes that this will be useful to others.

/*################################################
# Hardware PWM proof of concept using
# the Tiva C Launchpad
#
# Started with example code by
# lawrence_jeff found here:
# http://forum.stellarisiti.com/topic/707-using-hardware-pwm-on-tiva-launchpad/
# 
# Altered to use code found on section
# 22.3 of the TivaWare Peripheral Driver
# Library User's Guide found here:
# http://www.ti.com/lit/ug/spmu298a/spmu298a.pdf
#
#
# This example pulses three on-board LEDs
#
#################################################*/


#include "driverlib/pin_map.h"
#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_gpio.h"
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/pin_map.h"
#include "driverlib/gpio.h"
#include "driverlib/pwm.h"

void delayMS(int ms) {
    SysCtlDelay( (SysCtlClockGet()/(3*1000))*ms ) ;
}




int main(void)
{

    
    //Set the clock
   SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC |   SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);

   //Configure PWM Clock to match system
   SysCtlPWMClockSet(SYSCTL_PWMDIV_64);

   // Enable the peripherals used by this program.
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM1);  //The Tiva Launchpad has two modules (0 and 1). Module 1 covers the LED pins

    //
    // Unlock the Pin PF0 and Set the Commit Bit
    // See datasheet table 10-1 for explanation of
    // why this pin needs unlocking
    HWREG(GPIO_PORTF_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY;
    HWREG(GPIO_PORTF_BASE + GPIO_O_CR)   |= 0x01;


    //Configure PF0,PF1,PF2,PF3, and PA6 Pins as PWM
    //See table 20-1 for these assignments
    GPIOPinConfigure(GPIO_PA6_M1PWM2);
    GPIOPinConfigure(GPIO_PF0_M1PWM4);
    GPIOPinConfigure(GPIO_PF1_M1PWM5);
    GPIOPinConfigure(GPIO_PF2_M1PWM6);
    GPIOPinConfigure(GPIO_PF3_M1PWM7);
    GPIOPinTypePWM(GPIO_PORTA_BASE, GPIO_PIN_6);
    GPIOPinTypePWM(GPIO_PORTF_BASE, GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3);

    //Configure PWM Options
    //PWM_GEN_2 Covers M1PWM4 and M1PWM5
    //PWM_GEN_3 Covers M1PWM6 and M1PWM7 See table 20-1 for these assignments
    PWMGenConfigure(PWM1_BASE, PWM_GEN_1, PWM_GEN_MODE_DOWN | PWM_GEN_MODE_NO_SYNC);
    PWMGenConfigure(PWM1_BASE, PWM_GEN_2, PWM_GEN_MODE_DOWN | PWM_GEN_MODE_NO_SYNC); 
    PWMGenConfigure(PWM1_BASE, PWM_GEN_3, PWM_GEN_MODE_DOWN | PWM_GEN_MODE_NO_SYNC);
    
    //These settings are specifically designed to run servo motors
    //which expect 20mS period with between 1ms and 2ms high time
    //
    //System clock is 16MHz with PWM divider of 64
    // 16000000/64 = 250000/50 = 5000  ### 1S/50 = 20mS thats where divisor comes from
    unsigned long period = 5000;
    // Set high time to 2mS
    unsigned long pwmNow = period/10;

    //Set the Period (expressed in clock ticks)
    PWMGenPeriodSet(PWM1_BASE, PWM_GEN_1, period);
    PWMGenPeriodSet(PWM1_BASE, PWM_GEN_2, period);
    PWMGenPeriodSet(PWM1_BASE, PWM_GEN_3, period);

    //Set PWM duty
    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_2,pwmNow);
    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_4,pwmNow); 
    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_5,pwmNow);  
    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_6,pwmNow);
    PWMPulseWidthSet(PWM1_BASE, PWM_OUT_7,pwmNow);

    // Enable the PWM generator
    PWMGenEnable(PWM1_BASE, PWM_GEN_1);
    PWMGenEnable(PWM1_BASE, PWM_GEN_2);
    PWMGenEnable(PWM1_BASE, PWM_GEN_3);

    // Turn on the Output pins
    PWMOutputState(PWM1_BASE, PWM_OUT_0_BIT | PWM_OUT_2_BIT | PWM_OUT_4_BIT | PWM_OUT_5_BIT | PWM_OUT_6_BIT | PWM_OUT_7_BIT, true);

    while(1)
    {
       
    	delayMS(2000);
        //set high time to 1mS
        pwmNow = period/20;
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_2,pwmNow);
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_4,pwmNow);   
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_5,pwmNow);   
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_6,pwmNow);
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_7,pwmNow);

        delayMS(2000);
        //set high time to 2mS
        pwmNow = period/10;
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_2,pwmNow);
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_4,pwmNow);   
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_5,pwmNow);   
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_6,pwmNow);
        PWMPulseWidthSet(PWM1_BASE, PWM_OUT_7,pwmNow);
        
    }

}