TMS320F28P650DH: CRC calculation of large flash area using VCRC

Muhammad Salman

Part Number: TMS320F28P650DH

Tool/software:

I can calculate one block CRC successfully and as I have understood from the documentation that incase of large memory we need to split it in <= 0xFFFF and the result becomes the seed of next block.

flash area is 0x30000 -2 (0x60000 -4 bytes) words. so I am giving 95 x 4096 bytes in for loop and rest 4092 after for loop. unfortunately with no success.

for(u16i = 0; u16i < 95; u16i++)
{
// myVCRC0_CRC.pMsgBuffer = (uint16_t *)u16DataPointer;

memcpy(u16Array, (const void*)u16DataPointer,sizeof(u16Array));/**/

myVCRC0_CRC.run(myVCRC0_Handle);

u16DataPointer+= (4096/2);

myVCRC0_CRC.seedValue = myVCRC0_CRC.crcResult;
}

myVCRC0_CRC.nMsgBytes = 4092;

memcpy(u16Array, (const void*)u16DataPointer, (sizeof(u16Array)));/**/

myVCRC0_CRC.run(myVCRC0_Handle);

thanks and best regards

2 days ago

0 Sira Rao80 1 day ago

TI__Mastermind 22810 points

Muhammad,

Please check the value of sizeof(u16Array) and let me know. Is it 2048 or 4096?

Thanks,

Sira

0 Muhammad Salman 1 day ago in reply to Sira Rao80

Prodigy 10 points

Hi Sira,

it is 2048. I can get the result of single block correctly.

0 Sira Rao80 1 day ago in reply to Muhammad Salman

TI__Mastermind 22810 points

Hi Muhammad,

So that is the issue I believe - it needs to be 4096.

This is the effect of the F28x architecture that is not byte addressable - so it gives you sizeof(uArray) as 2048 and not 4096.

However, the VCRC function needs the input in number of bytes. So you should try

memcpy(u16Array, (const void*)u16DataPointer, (2 * sizeof(u16Array)));

Thanks,

Sira

0 Muhammad Salman 1 day ago in reply to Sira Rao80

Prodigy 10 points

Hi Sira,

I believe if I read from 2048 addresses in uint16 it is automatically 4096 bytes. as I mentioned if only calculate one block of 4096 bytes in 2048 Array, it gives me correct CRC.

However I have tried and it has same result as before.

0 Sira Rao80 1 day ago in reply to Muhammad Salman

TI__Mastermind 22810 points

Muhammad,

I am not sure what else is going on. Maybe troubleshoot with 2 blocks and see whether you get the right result.

0 Muhammad Salman 1 day ago in reply to Sira Rao80

Prodigy 10 points

yes works for two blocks.

0 Sira Rao80 1 day ago in reply to Muhammad Salman

TI__Mastermind 22810 points

Yes loading the seed for the next block with the crc result from the previous block is the correct approach.

If it works for 2 blocks, it should work for more. Maybe try a larger block size and see where it fails.

0 Muhammad Salman 1 day ago in reply to Sira Rao80

Prodigy 10 points

Thanks for the hint.

it works till block 31 at block 32 it fails

0 Sira Rao80 18 hours ago in reply to Muhammad Salman

TI__Mastermind 22810 points

So that means it works for 32 blocks, or 128KB of memory. What Flash address range are you computing the CRC on?

0 Muhammad Salman 12 hours ago in reply to Sira Rao80

Prodigy 10 points

one and half bank

0 Sira Rao80 9 hours ago in reply to Muhammad Salman

TI__Mastermind 22810 points

In the 32 block case, can you check the rest of the VCRC configuration parameters after the CRC compute to see if they are still at the expected values or if they have changed to some incorrect values?