GPIO data is not getting reflected on the external board pins

Vaishak R

Other Parts Discussed in Thread: OMAP-L138, OMAP-L137

Hi Sir/Madam,

GPIO output register data is not getting reflected on the pins,

I have followed all the instructions provided in the technical reference manual of OMAPL13X for initializing the board pins to work as GPIO.

i.e. 1. I have initialized the OMAP-L13X.

2. I have enabled the GPIO in PSC registers

3. I have also selected a GPIO pin 0 of register bank 8.

4. I tried toggling the pin HIGH and LOW.

5. But the same is not getting reflected on external pins provided on the board for testing purpose.

over 11 years ago

0 Norman Wong over 11 years ago

Guru 26430 points

Have you configured the pinmux?

0 Vaishak R over 11 years ago in reply to Norman Wong

Intellectual 495 points

Hi,

Yes i have selected the pinmux 19 bits 28 to 32 and configured to function as GPIO .

0 Pubesh over 11 years ago in reply to Vaishak R

TI__Mastermind 20790 points

Vaishak,

Enable the functional clocks for GPIO.
Enable the GPIO module using the API Call.
A GPIO pin can be used either as an input or an output pin. This direction of the GPIO pin is configured using the API Call.
When a GPIO pin is configured as an output pin: A logic HIGH or LOW could be driven on the specified GPIO pin by invoking the API GPIOPinWrite() passing appropriate parameters.

If GPIO peripheral interrupts will be used, System interrupt settings involves configuring the ARM processor and the Interrupt Controller(INTC) to handle peripheral interrupts.

The below wiki articles will help you when programming for GPIO,
http://processors.wiki.ti.com/index.php/Configuring_GPIO_Interrupts
http://processors.wiki.ti.com/index.php/Configuring_GPIO_EDMA_Events

0 Norman Wong over 11 years ago in reply to Vaishak R

Guru 26430 points

From your pinmux comment, I assume that you are using the OMAP-L138. The OMAP-L137 pinmux is different. When you say you "selected a GPIO pin 0 of register bank 8". Does that mean you wrote to direction and values registers? Perhaps you should post your code details of your environment. OS? Linux? u-boot? Bare metal? Board? LCDK?

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GPIO data is not getting reflected on the external board pins