DS21458 Datasheet, PDF (88/270 Pages) Dallas Semiconductor – Quad T1/E1/J1 Transceivers

DS21455/DS21458 Quad T1/E1/J1 Transceivers
15.2 Path Code Violation Count Register (PCVCR)
15.2.1 T1 Operation
The path code violation count register records either Ft, Fs, or CRC6 errors in T1 frames. When the
receive side of a framer is set to operate in the T1 ESF framing mode, PCVCR will record errors in the
CRC6 codewords. When set to operate in the T1 D4 framing mode, PCVCR will count errors in the Ft
framing bit position. Via the ERCNT.2 bit, a framer can be programmed to also report errors in the Fs
framing bit position. The PCVCR will be disabled during receive loss of synchronization (RLOS = 1)
conditions. See Table 15-3 for a detailed description of exactly what errors the PCVCR counts.
Table 15-3. T1 PATH CODE VIOLATION COUNTING ARRANGEMENTS
FRAMING MODE
D4
D4
ESF
COUNT Fs ERRORS?
No
Yes
Don’t Care
WHAT IS COUNTED IN THE PCVCRs
Errors in the Ft Pattern
Errors in Both the Ft and Fs Patterns
Errors in the CRC6 Codewords
15.2.2 E1 Operation
The PCVCR records CRC-4 errors. Since the maximum CRC-4 count in a one-second period is 1000, this
counter cannot saturate. The counter is disabled during loss of sync at either the FAS or CRC-4 level; it
will continue to count if loss of multiframe sync occurs at the CAS level.
The PCVCR1 is the most significant word and PCVCR2 is the least significant word of a 16-bit counter
that records path violations (PVs).
Register Name:
Register Description:
Register Address:
PCVCR1
Path Code Violation Count Register 1
44h
Bit #
Name
Default
7
6
5
4
3
2
PCVC15 PCVC14 PCVC13 PCVC12 PCVC11 PCVC10
0
0
0
0
0
0
1
PCVC9
0
0
PCVC8
0
Bits 0 to 7/Path Code Violation Counter Bits 8 to 15 (PCVC8 to PCVC15). PCVC15 is the MSB of the 16-bit path code
violation count.
Register Name:
Register Description:
Register Address:
PCVCR2
Path Code Violation Count Register 2
45h
Bit #
Name
Default
7
PCVC7
0
6
PCVC6
0
5
PCVC5
0
4
PCVC4
0
3
PCVC3
0
2
PCVC2
0
1
PCVC1
0
0
PCVC0
0
Bits 0 to 7/Path Code Violation Counter Bits 0 to 7 (PCVC0 to PCVC7). PCVC0 is the LSB of the 16-bit path code
violation count.
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