TMS320F28379D: Saving variables to flash memory

Aditya Ghule1

Part Number: TMS320F28379D
Other Parts Discussed in Thread: C2000WARE

Hi,

I am currently testing some code where I boot from flash memory and then load the program to RAM for faster execution. I want to try and save a few variable values in flash memory so that I can use the updated values of the variables every time I boot up the MCU, without having to download new code every time. Any direction/suggestions that I could follow would be really helpful.

Thank you,

Aditya

over 3 years ago

0 Vamsi Gudivada over 3 years ago

TI__Guru* 87155 points

Aditya,

How many times do you think you may have to update the variable in the life time of your product?

Thanks and regards,

Vamsi

0 Aditya Ghule1 over 3 years ago in reply to Vamsi Gudivada

Intellectual 440 points

Hi Vamsi,

Not very often. A few hundred times at most.

Thanks,

Aditya

0 Vamsi Gudivada over 3 years ago in reply to Aditya Ghule1

TI__Guru* 87155 points

Hi Aditya,

If that is the case, then you can simply allocate one sector (no need of two sectors for doing EEPROM emulation) and use the flash API to erase/program the value as needed.

Current datasheet is showing 20K max W/E cycling - but we are going to update the datasheet to reflect 100K for the entire flash (all sectors together). This is much beyond than what you need.

Thanks and regards,
Vamsi

0 Aditya Ghule1 over 3 years ago in reply to Vamsi Gudivada

Intellectual 440 points

Thanks Vamsi. I will test that. Is the 20k/ (now 100k) the amount of times the flash can be reprogrammed? If I want to look at the option of higher frequency of updating the variables do I need to look at EEPROM emulation ? Is there any example /documentation that you would recommend, as I have not explored flash programming on the 28379D a lot?

0 Vamsi Gudivada over 3 years ago in reply to Aditya Ghule1

TI__Guru* 87155 points

Hi Aditya,

Yes, you can erase/program for 100K times.

Yes, if you want to erase/program beyond that, it is not possible. If you want to update variables beyond that, you need to dedicate two sectors (minimum) and keep updating one sector serially until it is full - your application should always read the latest location for the updated value of the variable. Once the sector is full, you will switch to the second sector with the latest value and erase the full sector. This way, you can ping-pong between the two sectors for updating the variable value.

Regarding the flash API usage:

1. Example: C:\ti\c2000\C2000Ware_4_01_00_00\device_support\f2837xd\examples\dual\flash_programming

2. Flash API guide: http://www.ti.com/lit/pdf/spnu629

3. FAQ on Flash API usage for C2000 devices: https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/951668

4. FAQ for Flash ECC usage in C2000 devices: https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/951658

Thanks and regards,
Vamsi

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TMS320F28379D: Saving variables to flash memory