TM4C1231H6PGE: Interrupt synchronous to PWM frequency

Sorry,

I meant the TM4C123GH6PM not TM4C1231H6PGE.

This is the code I use for generating the PWM.

int main(void)
{
// Configure the clock to 80 MHz
SysCtlClockSet(SYSCTL_SYSDIV_2_5|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);

// PWM Initialization
SysCtlPWMClockSet ( SYSCTL_PWMDIV_64 ) ;
SysCtlPeripheralEnable ( SYSCTL_PERIPH_PWM1 ) ;
SysCtlPeripheralEnable ( SYSCTL_PERIPH_GPIOD ) ;

GPIOPinTypePWM ( GPIO_PORTD_BASE , GPIO_PIN_1 ) ;
GPIOPinConfigure ( GPIO_PD1_M1PWM1 ) ;

volatile uint32_t ui32PWMClock = SysCtlClockGet ( ) / 64 ;

volatile uint32_t ui32Load = ( ui32PWMClock / PWM_FREQUENCY ) - 1 ;

PWMGenConfigure ( PWM1_BASE , PWM_GEN_0 , PWM_GEN_MODE_DOWN ) ;
PWMGenPeriodSet ( PWM1_BASE , PWM_GEN_0 , ui32Load ) ;

PWMPulseWidthSet ( PWM1_BASE , PWM_OUT_1 , some_value) ;
PWMOutputState ( PWM1_BASE , PWM_OUT_1_BIT , true ) ;

PWMGenEnable ( PWM1_BASE , PWM_GEN_0 ) ;

while(1)
{
PWMPulseWidthSet ( PWM1_BASE , PWM_OUT_1 , some_other_value ) ;
}
}

Can you please post an example of how to make this peripheral generate an interrupt ?

Let me explain what I want to do:
I'm designing a control system that involves an I2C sensor and a motor controller.
The motor controller "speaks" PWM and is able to receive commands at a rate up to 400 Hz.

So 400 Hz is the rate I want to time my control loop to - I.E:
Take a reading from the sensor, make all the required calculations and send a one time update to the speed controller.

For this, I want to have the PWM peripheral generate the interrupt.
What do you think ?
Is this the best approach ?

Hi,

In addition to Bob's fine answers,

You configure PWM0 to generate interrupt on re-load count cycles. What you do in the much faster PWM interrupt handler to update i2C @400Hz is a software loop control issue, right? In such a configuration would faster PWM interrupt be asynchronous 400Hz update (2.5ms) speed controller?

I don't really understand your question...

This is what I want to do:

The speed controller expects to get PWM commands at 400 Hz.

So this is the PWM frequency I want the Tiva's module to generate - and I want all the software processes to be timed to it. I.E: reading I2C angle information, some minor filtering and calculating the required output.

To achieve that - my idea is to generate a 400 Hz interrupt from the PWM module, and have all the process marked in red execute under this interrupt's ISR.

I haven't done this yet...so my question to Bob was if such an approach is a good idea or not ? Or perhaps there's a better / simpler way...