3 Replies Latest reply on Aug 21, 2018 10:58 AM by user_331986238

    Is external crystal required for PSoC 5LP CAN at 1Mbps




      We are planning to use the CAN peripheral of a PSoc 5LP (CY8C5888AXI-LP096).  We would like to run the CAN bus at a baud rate of 1Mbps.  On page 12 of AN52701, it states the following: 


      "The CAN protocol does not transmit a clock to synchronize the bits. Synchronization between nodes is done for every

      bit transmitted, during the Sync Segment, as Figure 5 on page 4 shows. This requires the use of a highly accurate

      oscillator for baud rates greater than 125 Kbps.

      The CAN protocol specifies that the clock accuracy must be less than or equal to 0.5%. An error less than 0.1% can

      be achieved in PSoC by using an external crystal."


      Does this mean that an external crystal is required in order to run the CAN bus at a baud rate of 1 Mbps?  Or, is the external crystal just recommended?  In other words, is robust CAN communication at 1Mbps possible without an external crystal?


      Thanks for your help.