Reading ADC Gain Factor and ADC Offset from TLV structure

jose carlos cazarin

Intellectual 550 points

Hello all, i'm using the evaluation board for the MSP432P401R Rev 2.0 (the red one).

I'm having trouble reading these values from the TLV structure.

I'm using the CMSIS api with:

uint32_t gain_ADC = TLV->ADC_GAIN_FACTOR;

int32_t offset_ADC = TLV->ADC_OFFSET;

But they always read as 0xFFFFFFFF.

I've tried also with my code (I got the address value from page 178 of the datasheet revision D)

uint32_t* ptr_gain = ((uint32_t *)0x00201094);

gain_ADC = *ptr_gain;

uint32_t* ptr_offset = ((uint32_t *)0x002010D8);

offset_ADC = *ptr_offset;

But they read as 0xFFFFFFFF again.

I need some help here from TI personnel, or someone who could read the correct values of these settings.

Thanks!

over 8 years ago

0 Dennis Eichmann over 8 years ago

Guru 74080 points

Hi Jose!

Address 0x00201094h and 0x002010D8h are both reserved and might be empty (not defined, but probably 0xFFFFFFFFh):

Dennis

0 jose carlos cazarin over 8 years ago in reply to Dennis Eichmann

Intellectual 550 points

Which revision of the datasheet are you using Dennis?

Mine revision is D and it's like this:

0 Dennis Eichmann over 8 years ago in reply to jose carlos cazarin

Guru 74080 points

It is SLAS826E.

Dennis

0 Dennis Eichmann over 8 years ago in reply to jose carlos cazarin

Guru 74080 points

jose carlos cazarin said:
Mine revision is D

This was changed in revision E, look here:

Possible that Rev. D of the document belonged to Rev. B silicon and for some reason they decided to remove this memory content in the Rev. C silicon. Maybe they do not test this anymore, I don't know. Bad thing if you developed code on earlier silicon and now use the new parts that do not contain this information at the expected memory location. Dung Dang, are you still into those things?

Dennis

0 jose carlos cazarin over 8 years ago in reply to Dennis Eichmann

Intellectual 550 points

Thanks, didn't know that TI has a newer version, apparently they removed all the parts regarding the ADC calibration

0 Dung Dang over 8 years ago in reply to jose carlos cazarin

TI__Genius 17802 points

Hi Dennis,

CORRECTION: the differences are covered in the revision history. The following documents do not cover this specific changes today (plan to add details in the future), but they are generally good guidance as you move from early silicon revision to production silicon:

- Moving From Evaluation to Production With MSP432P401x MCUs Application Note that guides you through the differences between XMS and production MSP silicon.

- There is also a wiki site that provides more information as you move from XMS432 to production silicon: http://processors.wiki.ti.com/index.php/XMS432_Support

~Dung