After receiving a FD Format indicator (FDF) followed by a dominant res bit, the decoder unit waits for nBits_idle recessive bits before considering a further dominant bit as a SOF as per Figure 10-21. Table 10-3 defines nBits_idle.
|Number of recessive bits before a new SOF is accepted||nBits_idle||6||10|
There are two bitfilter options available to support different combinations of arbitration and data phase bit rates. Register 8'h47 is where the pBitfilter option is selected.
Dominant signals ≤ the minimum pBitfilter, see Table 10-4, of the arbitration bit time in duration is not considered valid and does not restart the recessive bit counter. Dominant signals ≥ the maximum of pBitfilter of the arbitration bit time duration restart the recessive bit counter.
|CAN FD data phase bitfilter 1||pBitfilter1||5.00%||17.50%|
|CAN FD data phase bitfilter 2||pBitfilter2||2.50%||8.75%|