topic Re: S12X CAN bus timing in S12 / MagniV Microcontrollers

S12X CAN bus timing

Pascalfm — Tue, 21 Dec 2010 06:22:03 GMT

Hi,

I'm currently setting up the CANbus on a S12XEP100. I've use the code coming with the dev board to start with and see how everything work. i'm using a kvaser CanKing as logger. I achieve to get clear data at 125 kb/s and 250 kb/s but when i tried to increase the speed I only get error frame...

For 125 kb/s I used those value :

BTR0=0x07

BTR1=0x3a

For 250kb/s I used those value :

BTR0=0x03

BTR1=0x3a

i tried 500 kb/s with those value

BTR0=0x01

BTR1=0x3a

i also tried the using the setting from the device inituialization tools but get the same problem.

Re: S12X CAN bus timing

kef — Tue, 21 Dec 2010 15:06:56 GMT

Maybe your bus driver is too slow for 500kbps, or maybe bus is not properly terminated?

Re: S12X CAN bus timing

Pascalfm — Wed, 22 Dec 2010 01:05:56 GMT

you are right, it's the transceiver speed I totally forgot about that one

I change the chip and everything is right now

thanks