LPC Microcontrollers中的主题 Re: Minimum CAN bit rate

Minimum CAN bit rate

lpcware — Wed, 15 Jun 2016 19:37:18 GMT

Content originally posted in LPCWare by danielwiedemann on Tue Jan 28 12:20:28 MST 2014
Hi,
I'm using the CAN interface of LPC11C14. While I'm working with Buadrate at 20kbit/s, all worked fine. But I need to use the CAN interface at 10kbit/s.
The CAN doesn't work, the BUS goes off.
I found out that there are the function "‘TXD dominant time-out", that defines a minimum possible bit rate.
Anybody knows how to disable this function on LPC11C14?
Thanks,
Daniel.

Re: Minimum CAN bit rate

lpcware — Wed, 15 Jun 2016 19:37:19 GMT

Content originally posted in LPCWare by LabRat on Tue Jan 28 12:43:19 MST 2014

Quote: danielwiedemann
Anybody knows how to disable this function on LPC11C14?

IIRC this is a transceiver function, so you can't disable it on your 11c14...

Which transceiver did you attach?

Re: Minimum CAN bit rate

lpcware — Wed, 15 Jun 2016 19:37:20 GMT

Content originally posted in LPCWare by danielwiedemann on Wed Jan 29 03:57:37 MST 2014
I've attached the ISO1050DUB.

Have I change the transceiver, to get low bit rate?

Re: Minimum CAN bit rate

lpcware — Wed, 15 Jun 2016 19:37:20 GMT

Content originally posted in LPCWare by LabRat on Wed Jan 29 04:33:53 MST 2014

Quote: danielwiedemann
I've attached the ISO1050DUB...

... with 'TXD Dominant Timeout (DTO)'. That's your problem...

Datasheet http://www.ti.com/lit/ds/symlink/iso1050.pdf :

Quote:
Minimum Bit Rate = 11/(tdom) = 11bits/300µs = 37kbps

If you (can) change your transceiver to SN65HVD23x (without DTO) 10kbps are no problem...

Re: Minimum CAN bit rate

lpcware — Wed, 15 Jun 2016 19:37:21 GMT

Content originally posted in LPCWare by danielwiedemann on Wed Jan 29 07:04:05 MST 2014
Thanks.