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Ixiasoft
4.1.2.1. Receive Path Blocks
The Interlaken IP core receive data path has the following four main functional blocks:
- RX PCS
- RX MAC
RX PCS
The FPGA soft logic implements RX PCS. In PAM4 mode, the IP core contains a soft logic transcoder block to work with RS FEC of the RX PMA. The Interlaken IP core RX PCS block performs the following functions to retrieve the data:
- Detects word lock and word synchronization.
- Checks running disparity.
- Reverses gear-boxing and 64/67B encoding.
- Descrambles the data.
- Delineates meta frame boundaries.
- Performs CRC32 checking.
- Sends lane status information to the calendar and status blocks, if Include in-band flow control functionality is turned on.
RX MAC
To recover a packet or burst, the RX MAC takes data from each of the PCS lanes and reassembles the packet or burst. The Interlaken IP core RX MAC performs the following functions:
- Data de-striping, including lane alignment and burst assembly from the PCS lanes.
- CRC24 validation.
- The 4th Point after the "turned on". The Interlaken IP core RX regroup block translates the IP core internal data format to the outgoing user application data irx_data format.
- Calendar recovery, if Include in-band flow control functionality is turned on.