TMS320F280049: maximum FLASH length for CRC and ERRATA notes

Viacheslav Potapov

Prodigy 30 points

Part Number: TMS320F280049
Other Parts Discussed in Thread: UNIFLASH

Hello,

I have several question regarding the C2000 linker and some errata notes:

Is it a good practice to combine several memory blocks (either RAM or FLASH) into one big, for example:
Flash sectors 3 to 15 into one big – FLASH_BANK0_SEC3_15 : origin = 0x083000, length = 0x00D000 ?
To calculate the CRC value of a memory block we are using this function:
uint32 getCRC32_vcu (uint32 input_crc32_accum, uint16 *msg, CRC_parity_e parity, uint16 rxLen);
But this function accepts a memory length only as a 16-bit value.
So, when we combine several sectors into one, linker can allocate a code in that way where its size is above 0x7FFF.
As I understood, before calling this function we should multiply the size by 2, as we need number of bytes rather than number of words.
If a code block in larger than 0x7FFF this multiplication overflows 16-bit value and the result is wrong.
Are there any other methods for checking code consistency? Now, linker generates CRC values for each sector (.text, .cinit, .econst, …) and these values are placed into a special memory range which is predefined. Then bootloader reads these values and compare them with calculated (by getCRC32_vcu). But if a block is larger than 0x7FFF comparison returns an error.
Does it make sense to not combine memory sectors in larger ones and keep them always smaller than 0x7FFF to not get an error similar above?
In the Errata for the F280049 there is a note: Memory: Prefetching Beyond Valid Memory. If M1 is only used for .stack, does this advice apply for this memory sector also, or we can use full memory (0x400 instead of 0x3F8)?

Thank you

Best regards,
Viacheslav Potapov

over 3 years ago

0 Vamsi Gudivada over 3 years ago

TI__Guru* 87155 points

Hi Viacheslav Potapov,

Thank you for reaching us with your queries.

We will review and get back to you in a day or two.

Thanks and regards,
Vamsi

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

TI__Guru* 87155 points

Hi Viacheslav Potapov,

If you enable ECC and read the entire memory range (periodically) that you want to ensure code consistency, it will let you know (via single and uncorrectable errors) if there is a difference from what was programmed.

Will that eliminate the CRC and the length issues that you mentioned?

Thanks and regards,

Vamsi

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

TI__Guru* 87155 points

Regarding #4: Stack should be fine. I will check and confirm.

Thanks and regards,
Vamsi

0 Viacheslav Potapov over 3 years ago in reply to Vamsi Gudivada

Prodigy 30 points

Hi Vamsi, thank you for the answer.

Well, the situation is a little different.

We need to check a program flashed exactly after flashing: if generated by liker CRC value the same as calculated CRC value after flashing.

The problem is, the getCRC32_vcu function accepts only data length up to 16 bit (so, up to 65535 bytes = 32767 words for C2000) , but we can combine flash sectors in more bigger memory (above 0x7FFF words) and this function will not be able to calculate CRC for so big sector.

So, if there is another way to compare CRC value generated by linker and CRC value for the program flashed?

Thank you.

0 Vamsi Gudivada over 3 years ago in reply to Viacheslav Potapov

TI__Guru* 87155 points

Viacheslav Potapov,

Which tool are you using to program the flash?

TI's CCS flash plugin and Uniflash can be used to calculate the checksum for the flash address range - And this checksum can be compared to the linker generated checksum.

If you want to go with CRC method, I can loop our CRC experts to help you further. Please let me know.

Thanks and regards,
Vamsi

0 Viacheslav Potapov over 3 years ago in reply to Vamsi Gudivada

Prodigy 30 points

Hi Vamsi,

we are using our own bootloader, and it checks CRC after flashing. For that we use getCRC32_vcu function.

If someone have ever used this function or if someone have ever calculated CRC after flashing from its own bootloader?

0 Viacheslav Potapov over 3 years ago in reply to Vamsi Gudivada

Prodigy 30 points

Hello Vamsi,

Have you checked this question? If M1 can be fully used for stack.

Thank you.

0 Vamsi Gudivada over 3 years ago in reply to Viacheslav Potapov

TI__Guru* 87155 points

Hi Viacheslav Potapov,

I will ask our team to assign this to our CRC expert.

Regarding the stack - I will let you know soon.

Thanks and regards,

Vamsi

+1 Vamsi Gudivada over 3 years ago in reply to Vamsi Gudivada

TI__Guru* 87155 points

Hi Viacheslav Potapov,

M1 can be fully used for stack.

Thanks and regards,

Vamsi

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

TI__Guru* 87155 points

Hi Viacheslav Potapov,

Our CRC expert is out of office until 21st. Please expect a reply at that time.

Thanks and regards,
Vamsi

0 Aravindhan K over 3 years ago in reply to Vamsi Gudivada

TI__Intellectual 2015 points

Hi,

We have used getCRC32_vcu function and it works fine. As you mentioned it has limitation on the length of bytes it can be called to compute the CRC. Did you try to use it for for a code block lesser than 0x7FFF and it works or you are seeing issues even in this case ?

Thanks

Aravindhan

0 Viacheslav Potapov over 3 years ago in reply to Aravindhan K

Prodigy 30 points

Hi Aravindhan,

thank you for the answer.

Yes, if I use blocks smaller than 0x7FFF, this function works. But if the block is larger, it doesn't.

The questions were:

1. Is it a good practice to combine several memory blocks (either RAM or FLASH) into one big, for example:
Flash sectors 3 to 15 into one big – FLASH_BANK0_SEC3_15 : origin = 0x083000, length = 0x00D000 ?

2. Are there any other methods for checking code consistency or if there another function to check bigger blocks (> 0x7FFF)?

3. Does it make sense to NOT combine memory sectors in larger ones and keep them always smaller than 0x7FFF to not get an error similar above?

Thank you.

Best regards,

Viacheslav Potapov

+1 Aravindhan K over 3 years ago in reply to Viacheslav Potapov

TI__Intellectual 2015 points

1. It is not a big issue to combine blocks or split them.

2. We do not have readily available routines for size greater than 0x7fff.

3. Yes, you can make smaller blocks and do CRC. It will take a few extra cycles since you have to call multiple times. I think it will not be a big concern. Can you try it out ?

Thanks Aravindhan

0 Viacheslav Potapov over 3 years ago in reply to Aravindhan K

Prodigy 30 points

Hi Aravindhan,

thank you for the answer,

yes, if block is smaller than 0x7FFF it works. I was surprised that linker can generate CRC value for larger blocks, but the function getCRC32_vcu cannot use them.

Thanks for the support, I will split the memory into smaller blocks.

Best regards,

Viacheslav Potapov

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F280049: maximum FLASH length for CRC and ERRATA notes