Achronix Speedster22i Interlaken - Manual (Page 31)

• Four consecutive invalid Meta Frame Synchronization Words were detected in the
corresponding lane, or
• Three consecutive invalid Scrambler State Control Words were detected in the
corresponding lane.
The bits of the bus remain asserted until word boundary synchronization occurs or until some
other error/failure is signaled for the corresponding lane.
stat_rx_descram_err[11:0]
When a bit of this bus is 1, it indicates that a Scrambler State Control Word with an unexpected
value was received on the corresponding lane. This bit is only asserted after word boundary
synchronization is achieved. This output is asserted for one clock period each time a descrambler
error is detected.
stat_rx_mf_err[11:0]
When a bit of this bus is 1, it indicates that an invalid Meta Frame Synchronization Word was
received on the corresponding lane. This bit is only asserted after word boundary
synchronization is achieved. This output is asserted for one clock period each time an invalid
Meta Frame Synchronization Word is detected.
stat_rx_aligned
When stat_rx_aligned is a value of 1, all of the lanes are aligned/de-skewed as explained in the
Interlaken Protocol Definition and the receiver is ready to receive packet data.
stat_rx_aligned_err
When stat_rx_aligned_err is a value of 1, one of two things occurred:
1. Lane alignment failed after several attempts, or
2. Lane alignment was lost (stat_rx_aligned was asserted and then it was negated).
stat_rx_framing_err[11:0]
When a bit of this bus is 1, an illegal framing pattern was detected on the corresponding lane
after word boundary synchronization. If this error is detected after lane alignment, the error is
treated like a CRC24 error (see the
Error Handling
section).
This output is asserted for one clock period each time an illegal framing pattern is detected.
RX Error Status
The IIPC provides status signals to identify Interlaken data transmission protocol violations in
sequences of Control and Data words. These are errors independent of the status of the Meta
Frame. Generally these signals do not indicate a failure on the part of the sending transmitter but
of some kind of corruption during the transmission.
All signals are synchronous with the rising-edge of clk and a detailed description of each signal
follows.
stat_rx_crc24_err
When this signal is a value of 1, it indicates that the error detection logic has identified a
mismatch between the expected and received value of CRC24 in a Control Word.
Every time a CRC24 error is detected, all open packets are marked as containing errors as
specified by the Interlaken ProtocolDefinition. By definition, there is no mechanism provided by
Interlaken to associate a CRC24 error with individual packets.
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