GX3290 Datasheet, PDF (29/47 Pages) Semtech Corporation – 290 x 290 3.5Gb/s Crosspoint Switch

The status of the two pattern checking blocks is available in the RX0_PRBS_LOCK and
RX1_PRBS_LOCK, RX0_PRBS_PASS and RX1_PRBS_PASS, RX0_PRBS_FAIL and
RX1_PRBS_FAIL, and RX0_PRBS_ERROR_COUNT and RX1_PRBS_ERROR_COUNT
read-only bits (see register addresses 0x81Eh to 0x821h).
• RX0_PRBS_LOCK [0] - When HIGH, indicates that the pattern checker has
acquired the pattern
• RX0_PRBS_PASS [1] - When HIGH, indicates that the pattern was locked, and the
specified number of words have been compared with fewer detected errors than
specified by the RX0_PRBS_BER_THRESH parameter
• RX0_PRBS_FAIL [2] - Indicates that the test terminated in a failure condition.
There are three possible failure conditions:
1. The pattern generator failed to lock in the number of attempts specified by
RX0_PRBS_LOCK_ATTEMPTS (in which case RX0_PRBS_LOCK would still be
'0').
2. The pattern generator locked, but over the period of time indicated by the
RX0_PRBS_LOL_TIME bits, a greater number of errors were detected than
allowed by the RX0_PRBS_LOL_THRESH setting. In this error condition, the
device determines that it has “lost lock“, and terminates the test. This error
condition is detectable if both RX0_PRBS_LOCK and RX0_PRBS_FAIL bits are
HIGH, and the value of RX0_PRBS_ERROR_COUNT is less than
RX0_PRBS_BER_THRESH (the same applies for RX1_PRBS_LOCK,
RX1_PRBS_FAIL and RX1_PRBS_ERROR_COUNT).
3. The pattern generator locked, but the number of errors observed exceeded the
value indicated by the RX0_PRBS_BER_THRESH bits. This error is detectable if
RX0_PRBS_LOCK and RX0_PRBS_FAIL are both HIGH, and the value of
RX0_PRBS_ERROR_COUNT is equal or greater than the value in
RX0_PRBS_BER_THRESH.
Note that the values of RX0_PRBS_LOCK and RX1_PRBS_LOCK, RX0_PRBS_PASS
and RX1_PRBS_PASS, RX0_PRBS_FAIL and RX1_PRBS_FAIL,
RX0_PRBS_ERROR_COUNT and RX1_PRBS_ERROR_COUNT are reset whenever
any of the corresponding test parameters for the RX0 and RX1 pattern checkers are
updated as well as whenever the corresponding RX0_PRBS_ENABLE or
RX1_PRBS_ENABLE bits are set to '1' when previously set to '0'. To start a new PRBS test
when the previous one has already been run, either re-write
RX0_PRBS_BER_TIME/RX1_PRBS_BER_TIME or toggle
RX0_PRBS_ENABLE/RX1_PRBS_ENABLE.
Note 2: The pattern checkers will count zero errors if the incident data is simply a static
zero.
GX3290 290 x 290 3.5Gb/s Crosspoint
Final Data Sheet Rev. 2
GENDOC-053317 March 2013
www.semtech.com
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Proprietary & Confidential