tm4c

Nabila Naorin

Hi Can someone please tell me how to set bits in these resistors?

    GPIO_PORTF_DIR_R 
    GPIO_PORTF_DEN_R 
    GPIO_PORTF_PUR_R

Regards
Nabila

over 11 years ago

0 Markel Robregado over 11 years ago

Guru 86755 points

Hi Nabila,

Nabila Naorin said:
these resistors?

Perhaps, do you mean "registers"?

Here is an example below.

HWREG(GPIO_PORTD_BASE + GPIO_O_DEN) |= 0x80;

You, can check other HWREG usage at gpio.c C API's.

HWREG macro can be found at \\inc\hw_types.h.

-kel

0 Nabila Naorin over 11 years ago in reply to Markel Robregado

Intellectual 600 points

Sorry yes registers. I mean is there two bits that needs to be set in combination in order to generate some signal in any PIN? Like for PCTL there are four bits. I looked at the data sheet. But it is quite confusing.

Thanks

Nabila

0 Markel Robregado over 11 years ago in reply to Nabila Naorin

Guru 86755 points

Hi Nabila,

Are you using a Tiva Launchpad?

I guess you want to output signal to GPIO. I would advice you to read the GPIO section of Tivaware Peripheral Drivers Library User's Guide. There is also an example gpio code that your can review.

-kel

0 Nabila Naorin over 11 years ago in reply to Markel Robregado

Intellectual 600 points

Yes i had a look at the document. It is not much relevant to what i am trying to do. Suppose for other registors like GPIOAMSEL how the different combination of bits trigger different output? How many comibinations are possible? How can i find the details about GPIOAMSEL,GPIOAFSEL

Regards

Nabila

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

Intellectual 600 points

Can anyone please explain me these:

GPIO_PORTF_DEN_R = 0x14; // 7) enable digital I/O on PF4, pf2

GPIO_PORTF_DATA_R=0x04; // set pf4 to 1

Thanks

Nabila

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

TI__Guru**** 244400 points

Hi Nabila,

In the datasheet section for GPIO, there is a table which explains the combination of the gpio registers and the effect of the register configuration on the output. For your reference see below;

If your question is how

GPIO_PORTF_DATA_R=0x04;

sets the Pin PF4 to 1, then you would need to look in the inc/tm4c*.h for the macro defitnition

Regards

Amit Ashara

0 Markel Robregado over 11 years ago in reply to Nabila Naorin

Guru 86755 points

Hi Nabila,

Refer, to your datasheet when trying to understand about registers. Do refresh your memory regarding hexadecimal and binary.

Nabila Naorin said:
GPIO_PORTF_DEN_R = 0x14; // 7) enable digital I/O on PF4, pf2

This is correct. Refer to GPIODEN register.

Nabila Naorin said:
GPIO_PORTF_DATA_R=0x04; // set pf4 to 1

This sets PF2 to 1, not PF4. Refer to GPIODATA register

-kel

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

Intellectual 600 points

Thank you Amit. One last thing, what about the AMSEL register? When do we need to set the bits of that register?

Thanks

Nabila

0 Nabila Naorin over 11 years ago in reply to Markel Robregado

Intellectual 600 points

Thank you Markel. I counted the bits wrong in binary

Regards

Nabila

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

TI__Guru**** 244400 points

Hi Nabila,

The AMSEL register is required to be set when a analog function like ADC, ACMP or USB pins have to be used.

Regards

Amit Ashara

0 Markel Robregado over 11 years ago in reply to Nabila Naorin

Guru 86755 points

@Nabila.

No problem at all. You, can also check tutorials in the internet for Tiva Launchpad.

-kel

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

Intellectual 600 points

Thank you everyone

Many thanks

Nabila

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