CCS/F28M35H52C: GPIO 21 doesn't work fine

zmeira

Prodigy 210 points

Part Number: F28M35H52C

Tool/software: Code Composer Studio

Hi,

I'm using the GPIO 21 of Concerto board.

These are my configuration at M3 side.

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);

GPIOPinConfigureCoreSelect(GPIO_PORTD_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);

These are my configuration at C29 side.

GpioG1CtrlRegs.GPAMUX2.bit.GPIO21 = 0; // Set as GPIO mode
GpioG1CtrlRegs.GPADIR.bit.GPIO21 = 1; // Set as output

I have un interrupt at 10Khz that can change the state of the GPIO. But I need to code two lines of the same command to real change the GPIO state:

GpioG1DataRegs.GPADAT.bit.GPIO21 = variable;
GpioG1DataRegs.GPADAT.bit.GPIO21 = variable;

If I let just one line, the GPIO doesn't stay on the new state, it works like in the picture.

over 8 years ago

0 Vivek Singh over 8 years ago

TI__Guru** 115881 points

Hi,

Do you have any other ISR/function, which toggles the same GPIO pin? Can you share the waveform when you are setting the GPIO pin two times?

Also if it's ok, please share the full ISR code.

Regards,
Vivek Singh

0 zmeira over 8 years ago in reply to Vivek Singh

Prodigy 210 points

Sorry, I didn't show all the problem. I saw that I can't change two GPIO pins one another. Like:

GpioG1DataRegs.GPADAT.bit.GPIO21 = variable1;
GpioG1DataRegs.GPADAT.bit.GPIO23 = variable2;

I don't know if the problem is that I'm setting the same port. In this case, the GPIO21 doesn't change like I need. But if I change the sequency:

GpioG1DataRegs.GPADAT.bit.GPIO23 = variable2;
GpioG1DataRegs.GPADAT.bit.GPIO21 = variable1;

Now, is the GPIO 23 that doesn't work properly.

If you have any idea why does it happens. I will thank you. if I put any command line between the GPIO set commands, all works fine. It's like it needs a time to correctly change the port state.

0 Brett Larimore over 8 years ago in reply to zmeira

TI__Guru 57255 points

Hi,

Please see the below:
http://processors.wiki.ti.com/index.php/General_Purpose_IO_(GPIO)_FAQ_for_C2000#Q:_Back-to-back_DAT_register_writes_do_not_work_as_expected

Thank you,
Brett

C2000™︎ microcontrollers

C2000 microcontrollers forum

CCS/F28M35H52C: GPIO 21 doesn't work fine