GX3290 Datasheet, PDF (28/47 Pages) Semtech Corporation – 290 x 290 3.5Gb/s Crosspoint Switch

Table 4-7: Checking Modes
RX0_PRBS_CHK_MODE[1:0] (binary)
00
01
10 or 11
Input Mode
Check data sampled at neutral phase
Check data sampled at adjustable phase
Compare nominally sampled data with phase
offset data (allows eye monitoring of
arbitrary patterns)
The pattern checker will check for the PRBS pattern specified by the
RX0_PRBS_POLYNOMIAL and RX1_PRBS_POLYNOMIAL bits (addresses 0x803h
and 0x811h respectively).
The PRBS checkers are enabled by the RX0_PRBS_ENABLE and RX1_PRBS_ENABLE
bits (register address 0x81Dh[1:0]).
Table 4-8: Checked Patterns
RX0_PRBS_POLYNOMIAL[1:0] (binary)
00
01
10
Pattern Checked
PRBS7
PRBS15
PRBS23
The incident data can be inverted before checking by setting the corresponding
RX0_INVERT_PRBS_IN or RX1_INVERT_PRBS_IN bit (address 0x803h[2:2] and
0x811h[2:2]) to '1'.
The number of words to be compared is selectable via the corresponding
RX0_PRBS_BER_TIME and RX1_PRBS_BER_TIME bits (registers 0x80Ah and
0x817h).
Table 4-9: Compared Words
RX0_PRBS_BER_TIME[3:0] (binary)
Number of words* compared (decimal)
0000
Infinite
0001
13
0010
26
0011
3277
0100
6554
0101
838861
0110
1677722
*Note: Each word is comprised of 10 bits, therefore the actual number of samples compared is
10 times the number of words compared.
GX3290 290 x 290 3.5Gb/s Crosspoint
Final Data Sheet Rev. 2
GENDOC-053317 March 2013
www.semtech.com
28 of 47
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