GPIOPCTL

Nabila Naorin

Hi how many bits need to be set for GPIOPCTL? As per page 686 there are total 32 bits. But previously i have come across something like 16 bits need to be set in order to enable alternate functions?

Thanks

Nabila

over 11 years ago

0 Amit Ashara over 11 years ago

TI__Guru**** 244400 points

Hi Nabila.

In TM4C123, the alternate functions are now a 4-bit field per pin. Thus for 8 pins of every port it is now a total of 32 bits. Please note that it is one nibble per pin.

Regards

Amit Ashara

0 Nabila Naorin over 11 years ago in reply to Amit Ashara

Intellectual 600 points

Thank you very much Amit.

So if i want to enable GPIO on PA7, i need to write the following right?

GPIO_PORTA_PCTL_R &= 0x0FFFFFFF; // 4) PCTL GPIO on PA7(28-31)

Thanks

Nabila

0 Amit Ashara over 11 years ago in reply to Nabila Naorin

TI__Guru**** 244400 points

Hello Nabila,

If you want to enable GPIO on PA7 then you need to set the corresponding AFSEL register bit to 0 and the PCTL nibble for the pin as 0.

GPIO_PORTA_PCTL_R &= 0x0FFFFFFF;

GPIO_PORTA_AFSEL_R &= 0x7F;

Regards

Amit Ashara

0 Nabila Naorin over 11 years ago in reply to Amit Ashara

Intellectual 600 points

Thank you for the explanation

Regards

Nabila

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GPIOPCTL