Receiver (RX)

The receiver performs the following functions:

  • Uses the gearbox to convert the SerDes 32b data into 66b data.
  • Monitors the data from the SerDes interface for BER and sync headers when signal_ok is asserted.
  • When not in FEC mode, the receiver achieves 66b block synchronization by shifting one bit at a time until a succession of valid synchronization bits are seen.
  • In FEC mode, it performs FEC descrambling, FEC framing synchronization, FEC decoding, and data correction (if an error happens).
  • In FEC mode, the decoder can be configured to indicate errors.
  • Descrambles the 66b received data using the G(x) = 1 + x39 + x58 polynomial
  • Performs 64b/66b decoding on the 66b data block to obtain the 64b data and 8b control data for the MAC.
  • De-replicates the received code words to the relevant MAC sub-rate.
  • Inserts or deletes idle characters to adapt between the host clock and recovered clock.
  • Deletes control sequence characters to adapt between the host clock and recovered clock.
  • Performs test pattern checking.

Figure 1. 10GBase-KR Receiver