CRC Module

[acelec]

Posted on October 01, 2012 at 15:44

Hello

Is there any difference between the CRC module at STM32F1 Series and STM32F3 Series.? I saw that there are some new registers active and some new features possible ! #crc #crc #crc

[Tesla DeLorean]

Posted on October 01, 2012 at 16:33

I saw that there are some new registers active and some new features possible !

Per the library, you can control the size (7, 8, 16 and 32-bit), polynomial and bit direction.

[acelec]

Posted on October 02, 2012 at 08:02

Thx Clive

Is it only change(update) in the Library and can I use F1 Series CRC with these features ( polynomial size etc. )  by changing the library file ?  

[Tesla DeLorean]

Posted on October 02, 2012 at 15:34

Is it only change(update) in the Library and can I use F1 Series CRC with these features ( polynomial size etc. )  by changing the library file ?

I'm not sure I understand the question. It can perform the same calculation as the F1 series, and many others. I would suggest you refer to the reference manual. Pg 70

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/DM00043574.pdf

[acelec]

Posted on October 02, 2012 at 16:31

Sorry , I have to go to the details:

If you compare reference manual for F1 and Refrence manual for F3 Series you will see that  for  example register CRC_CR has no settings for polynomial size  - there is only one bit (RESET) referenced. I am asking myself is ST is using two different CRC units for F1 and F3 Series?? That would be nonsense from my point of view! Can I set polynomial size on F1 Series etc. just as I can do it with F3 Series even if it is not referenced in the reference manual for F1 ..?? Hope I explained it well !  

[Tesla DeLorean]

Posted on October 02, 2012 at 16:47

The silicon in the F1 remains the same, it supports a single, fixed, 32-bit polynomial, in a backward endian fashion.

The F3 implements a more flexible/powerful CRC solution. It's clearly a different design, given the complaints/flaws/omissions in the prior design. On the F1 you will need to implement different CRC solutions in software, yourself.

[acelec]

Posted on October 03, 2012 at 08:13

Thanks Clive, that is exactly what I ment !

[acelec]

Posted on October 03, 2012 at 10:23

What is the best way to use this ''old style'' F1 CRC Modul for CRC8 test, what would be your recomendation ?

Thanks!

[Tesla DeLorean]

Posted on October 03, 2012 at 14:06

What is the best way to use this ''old style'' F1 CRC Modul for CRC8 test, what would be your recomendation ?

You wouldn't, the unit is going to be useless for anything but the polynomial it was designed for, and it's reverse. You'd need to use classic byte or bit software implementations for the polynomial in question.