HOW TO SET THE BXCAN R1 AND R0 ?

[Kenta Chang]

Posted on February 02, 2018 at 18:32

Hello, 

I run the CAN loopback example project by NUCLEO-F446ZE. And find a problem, may I to set the r1 and r0 ? I read the RM0390, no message about it. Could you please let me know How to set the r1 & r0 bits?

[T J]

Posted on February 03, 2018 at 02:38

I don't think you can set those bits, it looks like they are reserved by the hardware here.

Why do you need to set those ?

[Kenta Chang]

Posted on February 03, 2018 at 07:54

When I run the Extented Remote Frame and DLC is 0, I hope to set r1 & r0  to needn't  [1] bit stuff.  If I set r0 'recessive' , and DLC is 0 , there isn't  

[1] bit stuff.

 

[T J]

Posted on February 03, 2018 at 08:06

Why do you want to play there ?,

R0,R1, are 'Firmware bits that are used to drive the canbus.

[Kenta Chang]

Posted on February 03, 2018 at 12:41

I find a solution to this issue.  Don't care the r1 or r0 value.

When I run the Extented Remote Frame,  I set the DLC is  [1111],  and there isn't  [1] bit stuff on the bit stream waveform. 

[T J]

Posted on February 03, 2018 at 13:41

Without the line drivers, I found the CanRxpin needed a pullup, or the hardware would hang on startup.

Can you receive a frame ?

Do you have a know good transmitter on a bus ?

Best to use a dongle to transmit a known good frame first, then you work on your receiver first.

[Kenta Chang]

Posted on February 06, 2018 at 08:03

THANKS