AM5728: GPIO interrupts

Ameer Hamza

Part Number: AM5728

Dear all,

I have a question regarding AM572x GPIO controller. By reading the reference manual i observed that GPIO instance has two Interrupt lines which can be independently configured. But by looking at the Edge Triggering registers, Its not available for both the instances. So I am bit confused if we enabled both the line would Edge Trigger not be independent for both of them. If no what exactly is the use case of having two interrupt lines. For example: If i want to configure GPIO 1 to for independently for both the "Rising Edge" and "Falling Edge", Would it be possible ? Thanks in advance.

Best Regards,

Hamza.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

It's possible to generate separate GPIO interrupts for rising and falling edge on the same pin. For instance, interrupt generation on both edges on input k is configured by setting to 1 the k-th bit in registers GPIO_RISINGDETECT and GPIO_FALLINGDETECT along with the interrupt enabling for one or both interrupt lines (GPIO_IRQSTATUS_SET_n). However your ISR will need to read the pin level to determine which edge has fired the interrupt.

0 Ameer Hamza over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Hi Biser,

Your quick response is always appreciated. But I still have some confusion, when enabling Interrupt (GPIO_IRQSTATUS_SET_n) how we distinguish which interrupt is set for the "Rising Edge" and which one is set for the "Falling Edge". Ideally we should know when in ISR, particular vector ID has occur for "Rising Edge" or "Falling Edge" or "Low / High " Level, etc.

Best Regards,
Hamza.

0 Biser Gatchev-XID over 8 years ago in reply to Ameer Hamza

TI__Guru**** 393215 points

The sequence is like this:

• Interrupts for the GPIO channel must be enabled in the GPIO_IRQSTATUS_SET_0 and/or GPIO_IRQSTATUS_SET_1 registers.

• The expected event(s) on input GPIO to trigger the interrupt request has to be selected in the GPIO_LEVELDETECT0, GPIO_LEVELDETECT1, GPIO_RISINGDETECT, and GPIO_FALLINGDETECT registers.

0 Ameer Hamza over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Hi Biser,

I don't have any confusion in your described workflow. I just want to know if we enable both the interrupts GPIO_IRQSTATUS_SET_0, GPIO_IRQSTATUS_SET_1 for a specific GPIO Line. And we want to configure "GPIO_IRQSTATUS_SET_0" to "Rising Edge" trigger and "GPIO_IRQSTATUS_SET_1" to falling edge interrupt how can we achieve this. Since "Rising / Falling" edge trigger are shared for both the lines, but both IRQs have different vector ids.

Thanks,
Hamza.

0 Biser Gatchev-XID over 8 years ago in reply to Ameer Hamza

TI__Guru**** 393215 points

Ameer Hamza said:
I just want to know if we enable both the interrupts GPIO_IRQSTATUS_SET_0, GPIO_IRQSTATUS_SET_1 for a specific GPIO Line.

This will generate two interrupts for the same event. It doesn't make sense doing this.

Ameer Hamza said:
And we want to configure "GPIO_IRQSTATUS_SET_0" to "Rising Edge" trigger and "GPIO_IRQSTATUS_SET_1" to falling edge interrupt how can we achieve this.

This cannot be done, as I explained in my first post.

0 Biser Gatchev-XID over 8 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

to summarize: If you want to generate two separate interrupts for both edges, you will need to input the signal on two GPIO pins. One pin configured for falling edge and interrupt 0, and the other for rising edge and interrupt 1.

0 Ameer Hamza over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Hi biser,

My confusion is getting clear. Just one last question, what is exactly the use case of GPIO_IRQSTATUS_SET_1 (of having second interrupt line) ? Thanks for all the support.

Best Regards,
Hamza.

0 Biser Gatchev-XID over 8 years ago in reply to Ameer Hamza

TI__Guru**** 393215 points

This allows you to have a separate interrupt for one or more signals within a GPIO module.

0 Ameer Hamza over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

I got it now. So its always good for a specific GPIO pin to enable only one interrupt. And this feature would fancy two interrupts within the module. Right ?

Thanks,
Hamza.

0 Biser Gatchev-XID over 8 years ago in reply to Ameer Hamza

TI__Guru**** 393215 points

Yes.

0 Ameer Hamza over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Thank you so much :)

Processors

Processors forum

AM5728: GPIO interrupts