GX3146 Datasheet, PDF (26/46 Pages) Semtech Corporation – Crosspoint Switch with Trace Equalization and Output De-emphasis

The pattern checker allows a true measurement of bit error rate for the supported PRBS
sequences in the first two modes above. The third, arbitrary data comparison mode,
gives an indication of the degree of eye closure at a given sampling phase offset, but
cannot detect bit errors in the incident data. See Figure 4-1 and Figure 4-2 below.
EXT_PG0/EXT_PG0
Input 144 Crosspoint Core Output 144
(146 x 146)
MON0/MON0
/2 /11
Serializer/
Pattern
Generator
Pattern
/2 CMU _{Generator 0}
xtal osc.
27MHz
CDR
/2
Pattern
Checker 0
Neutral
Phase
Deserializer
Variable
Phase
Deserializer
Pattern Checker
Figure 4-1: Simplified Pattern Generator/Checker Zero Block Diagram
EXT_PG1/EXT_PG1
Input 145 Crosspoint Core Output 145
(146 x 146)
MON1/MON1
/2 /11
Serializer/
Pattern
Generator
Pattern
/2 CMU _{Generator 1}
xtal osc.
27MHz
CDR
/2
Pattern
Checker 1
Neutral
Phase
Deserializer
Variable
Phase
Deserializer
Pattern Checker
Figure 4-2: Simplified Pattern Generator/Checker One Block Diagram
Note: There are two pattern checker “Rx” blocks in the GX3146. In the following,
wherever only RX0 is mentioned, the corresponding is also true for RX1.
GX3146 146 x 146 3.5Gb/s Crosspoint
Final Data Sheet Rev. 2
GENDOC-056075 March 2013
www.semtech.com
26 of 46
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