On 01.10.2010 18:55, Uwe Bonnes wrote: >>>>>> "Ewgenij" == Ewgenij Sokolovski <[email protected]> writes: > > Ewgenij> Hmm, and what is the way to compute the value of the parameter? > Ewgenij> Why the value for 100 kbit/s is 0x4914? I need 500 kbit/s and > Ewgenij> 125 kbit/s... BR Ewgenij > > Did you have a look at the pEAK documentation. There is a list of values to > set...
There's also a tool in the SocketCAN SVN that gives correct settings for the SJA1000 bittiming registers (BTR) : u...@host:~/socketcan/trunk/can-utils$ ./can-calc-bit-timing Bit timing parameters for sja1000 with 8.000000 MHz ref clock nominal real Bitrt nom real SampP Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error BTR0 BTR1 1000000 125 2 3 2 1 1 1000000 0.0% 75.0% 75.0% 0.0% 0x00 0x14 800000 125 3 4 2 1 1 800000 0.0% 80.0% 80.0% 0.0% 0x00 0x16 500000 125 6 7 2 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00 0x1c 250000 250 6 7 2 1 2 250000 0.0% 87.5% 87.5% 0.0% 0x01 0x1c 125000 500 6 7 2 1 4 125000 0.0% 87.5% 87.5% 0.0% 0x03 0x1c 100000 625 6 7 2 1 5 100000 0.0% 87.5% 87.5% 0.0% 0x04 0x1c 50000 1250 6 7 2 1 10 50000 0.0% 87.5% 87.5% 0.0% 0x09 0x1c 20000 3125 6 7 2 1 25 20000 0.0% 87.5% 87.5% 0.0% 0x18 0x1c 10000 6250 6 7 2 1 50 10000 0.0% 87.5% 87.5% 0.0% 0x31 0x1c (..) There you can see 0x001C for 500kBit/s (which is the default in the PEAK driver). For your 125kBit/s bus you need to use 0x031C AFAIK there's also a bitrate calculation tool for MS Win on the PEAK site. Regards, Oliver _______________________________________________ Socketcan-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-users
