TMS320F280049: Launchpad 28004x_pmbus_master example

Part Number: TMS320F280049
Other Parts Discussed in Thread: C2000WARE

Hi everyone!

I'm evaluating the PMBUS on the F280049 Launchpad as a master device. I'm running the 28004x_pmbus_master from C2000Ware but am having difficulties getting the example to work. Right now, I am just trying to scope the PMBUS pins and see the device attempt to transmit something at the GPIO level, but running the example doesn't seem to cause a transmission to a slave device. I made some modifications to the GPIOs the example was using for the Launchpad because some of the default pins were unable to be toggled in GPIO output mode (probably jumper or port settings on the Launchpad), so I'm using the GPIOs as shown below and set the scope to trigger on each of the pins but it never captured anything. There is not a slave device connected so I am not expecting the example to "pass", but I am expecting to see data transmitted on the bus. I tried adding a while() loop with a delay around the PMBus_putMasterData to make it continuously transmit and still couldn't see anything going across the wire. I have glanced through the PMBUS_COMMS_STACK_UG but seems it is mostly focused on the slave mode of operation.

Is there any documentation on this example or other PMBUS examples you can share to help get started? I have started reading the "PMBUS_COMMS_STACK_UG" library document and doing debug, but wanted to reach out in the meantime to make sure there wasn't something simple I was missing.

Thanks in advance,

Kris

void PMBUS_Example_setupGPIO( void )
{
    // PMBus module is accessible over other GPIO pin mux configurations 
    // as well. Refer to the device TRM for the different pin configurations
    GPIO_setPinConfig(GPIO_26_PMBACTL);
    GPIO_setPinConfig(GPIO_13_PMBAALRT);
    GPIO_setPinConfig(GPIO_34_PMBASDA);
    GPIO_setPinConfig(GPIO_3_PMBASCL);
}