Polynomial used in calculating BSL_Scripter.exe CRC

Epic Vancouver

I am trying to configure our C compiler (IAR) to calculate the CRC over a section of application code that will be loaded into Flash using BSL_Scripter.exe from TI. BSL_Scripter.exe does a CRC calculation at the end of the load process and I would like to give it the CRC calculated by IAR. However, I can’t seem to get a match between the CRC calculated by BSL_Scripter.exe and IAR. I am wondering if you could me find out how the CRC is calculated for the BSL_Scripter.exe? What I really need is to know the polynomial and any initial valued used in the calculation.

over 15 years ago

0 Divesh Dang 18431815 over 15 years ago

TI__Prodigy 70 points

Epic Vancouver,

the BSL (both BSL Scripter and BSL code) uses the CRC-CCITT-BR standard, with
the polynomial: f(x) = x^16 + x^12 + x^5 +1
and the initial seed = 0xFFFF

You can use this online calculator to verify the CRC of your data: http://www.lammertbies.nl/comm/info/crc-calculation.html

Implementation in C can be found in the BSL_Scripter source code (in CRC.c), which can be found at this page http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=slaa096e. This page also contains the link to the Memory Programming Guide.

The newer MSP430x5xx devices (all 5xx except non-A msp430x54x) have a hardware CRC module that also uses this standard. More info can be found in Chapter 10 of the 5xx User's Guide http://www.ti.com/lit/pdf/SLAU208

0 Engrforever over 14 years ago in reply to Divesh Dang 18431815

Intellectual 480 points

From the reading the 5xx User's Guide, I understand something is different about the CRC module.

Are you telling us the CRC module cannot be used at all? I have tried bit-reversing and cannot seem to figure out what is going on inside the CRC module.

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Polynomial used in calculating BSL_Scripter.exe CRC