stm32f0 discovery CAN bit timing

[urban]

Posted on November 19, 2014 at 17:29

Hello,

I'm having problems with bit timing configuration. I have 36MHz peripheral clock and need 500kBit/s on CAN. I'm having trouble, because I've calculated right value but I see on the oscilloscope that it isn't . Can someone please help me? CAN_InitStructure.CAN_Prescaler = 3; CAN_InitStructure.CAN_SJW = CAN_SJW_1tq; CAN_InitStructure.CAN_BS1 = CAN_BS1_12tq; CAN_InitStructure.CAN_BS2 = CAN_BS2_3tq;thanks in advance

[Tesla DeLorean]

Posted on November 19, 2014 at 18:04

By my estimation you have a 750kbaud setting

APB / ((SWJ + BS1 + BS2) * Prescaler) ie APB / 48 You'd need APB / 72 for a 500kbaud rate from a 36 MHz bus clock.

[Tesla DeLorean]

Posted on November 19, 2014 at 18:07

/* CAN Baudrate = 500KBps for 36 MHz */

  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq; // 1..4   CAN_InitStructure.CAN_BS1 = CAN_BS1_3tq; // 1..16   CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq; // 1..8   CAN_InitStructure.CAN_Prescaler = 8; // 1..1024   CAN_Init(CANx, &CAN_InitStructure);

[urban]

Posted on November 21, 2014 at 13:02

Thank you very much. it's working now.