IDT Tsi578, User Manual

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3. Serial RapidIO Electrical Interface > Bit Error Rate Testing (BERT) 82
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
3.9.2 BERT Pattern Matcher and Error Counter
The pattern matcher is capable of synchronizing to and detecting erroneous bytes in the two LFSR
patterns mentioned in
Table 9 . Erroneous bytes are counted in the error counter in the “SerDes Lane 0
Pattern Matcher Control Register” on page 407 .
When the MODE field in the “SerDes Lane 0 Pattern Matcher Control Register” on page 407 is set to
3’b001 or 3’b010, the pattern matcher operates by generating the expected pattern and synchronizing to
the incoming pattern.
The Error Count (COUNT) field in the “SerDes Lane 0 Pattern Matcher Control Register” on page 407
is a 15-bit value. Together with the OV14 bit, a total of 2
22
- 2
7
- 1 errors can be reported. When the
OV14 bit is set, the count value should be read as count*128.
3.9.3 Fixed Pattern-based BERT
Fixed pattern-based BERT uses data in software-configurable registers to send an alternating pattern of
10-bit 8B10B code groups. Fixed pattern-based BERT does not produce error count results.
Fixed patterns are programmed in the PAT0 field and selected by setting the appropriate MODE field in
the
“SerDes Lane 0 Pattern Generator Control Register” on page 403 .
The following three patterns are useful for BERT testing:
• pat0 = 1010101010 creates a high-frequency pattern, with SMACx_PG_CTL.mode=3’b011
• pat0 = 0011111000, ~pat0 = 1100000111 creates a low-frequency pattern, with
SMACx_PG_CTL.mode=3’b100
Table 9: Patterns Supported by Matcher
MODE Settings Description
0 Pattern Matcher and Error Counter are disabled
1 Expect 15
th
order lfsr polynomial: x
15
+ x
14
+ 1
2 Expect 7
th
order lfsr polynomial: x
7
+ x
6
+ 1
3 Expect d[n]=d[n-10]
4 Expect d[n]=!d[n-10]
5:7 reserved
The Pattern Generator and Matcher are independently controllable within the same lane.
They do not need to be enabled, or programmed, the same way. For example, the Tsi578 can
transmit a different PRBS pattern than the pattern it is receiving.