2 bert repetitive pattern set – Maxim Integrated DS21Q55 User Manual
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25.2 BERT Repetitive Pattern Set
These registers must be properly loaded for the BERT to generate and synchronize to a repetitive pattern,
a pseudorandom pattern, alternating word pattern, or a Daly pattern. For a repetitive pattern that is less
than 32 bits, the pattern should be repeated so that all 32 bits are used to describe the pattern. For
example, if the pattern was the repeating 5-bit pattern …01101… (where the right- most bit is the one sent
first and received first) then BRP1 should be loaded with ADh, BRP2 with B5h, BRP3 with D6h, and
BRP4 should be loaded with 5Ah. For a pseudorandom pattern, all four registers should be loaded with
all ones (i.e., FFh). For an alternating word pattern, one word should be placed into BRP1 and BRP2 and
the other word should be placed into BRP3 and BRP4. For example, if the DDS stress pattern “7E” is to
be described, the user would place 00h in BRP1, 00h in BRP2, 7Eh in BRP3, and 7Eh in BRP4, and the
alternating word counter would be set to 50 (decimal) to allow 100 bytes of 00h followed by 100 bytes of
7Eh to be sent and received.
Register Name:
BRP1
Register Description:
BERT Repetitive Pattern Set Register 1
Register Address:
DCh
Bit #
7
6
5
4
3
2
1
0
Name
RPAT7
RPAT6
RPAT5
RPAT4
RPAT3
RPAT2
RPAT1
RPAT0
Default
0
0
0
0
0
0
0
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 0 to 7 (RPAT0 to RPAT7). RPAT0 is the LSB of the 32-bit repetitive pattern
set.
Register Name:
BRP2
Register Description:
BERT Repetitive Pattern Set Register 2
Register Address:
DDh
Bit #
7
6
5
4
3
2
1
0
Name
RPAT15
RPAT14
RPAT13
RPAT12
RPAT11
RPAT10
RPAT9
RPAT8
Default
0
0
0
0
0
0
0
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 8 to 15 (RPAT8 to RPAT15).
Register Name:
BRP3
Register Description:
BERT Repetitive Pattern Set Register 3
Register Address:
DEh
Bit #
7
6
5
4
3
2
1
0
Name
RPAT23
RPAT22
RPAT21
RPAT20
RPAT19
RPAT18
RPAT17
RPAT16
Default
0
0
0
0
0
0
0
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 16 to 23 (RPAT16 to RPAT23).
Register Name:
BRP4
Register Description:
BERT Repetitive Pattern Set Register 4
Register Address:
DFh
Bit #
7
6
5
4
3
2
1
0
Name
RPAT31
RPAT30
RPAT29
RPAT28
RPAT27
RPAT26
RPAT25
RPAT24
Default
0
0
0
0
0
0
0
0
Bits 0 to 7/BERT Repetitive Pattern Set Bits 24 to 31 (RPAT24 to RPAT31). RPAT31 is the LSB of the 32-bit repetitive
pattern set.