38.3.3.6 Recommendations for Bit Time Configuration

The following recommendations need to be considered when configuring the bit time:

  • Select the highest available CAN clock frequency:
    • Short TQ leads to high resolution to select the sample point.
    • Use 20 MHz or 40 MHz for SYSCLK.
  • Select the lowest NBRP:
    • Low BRP leads to short TQ.
    • NSYNC will be short and reduce the quantization error.
    • The receiving node can synchronize more accurately to the transmitting node.
  • Use the same Nominal Sample Point (NSP) in all nodes on the CAN network:
  • Select the largest possible NSJW:
    • Maximizes the oscillator tolerance.
    • Allows the receiving nodes to quickly resynchronize to the transmitting nodes.