Datasheet

DS2155
78 of 238
14.2 Path Code Violation Count Register (PCVCR)
14.2.1 T1 Operation
The path code violation count register records 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 records errors in the CRC6 codewords.
When set to operate in the T1 D4 framing mode, PCVCR counts errors in the Ft framing bit position.
Through the ERCNT.2 bit, a framer can be programmed to also report errors in the Fs framing bit
position. The PCVCR is disabled during receive loss-of-synchronization (RLOS = 1) conditions.
Table 14-C shows what errors the PCVCR counts.
Table 14-C. T1 Path Code Violation Counting Arrangements
FRAMING MODE COUNT Fs ERRORS?
COUNTED
IN THE PCVCRs
D4 No Errors in the Ft pattern
D4 Yes Errors in both the Ft and Fs patterns
ESF Don’t Care Errors in the CRC6 codewords
14.2.2 E1 Operation
The path code violation-count register records CRC4 errors. Since the maximum CRC4 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 CRC4 level; it continues to count if loss-of-multiframe sync occurs at the CAS level.
Path code violation-count register 1 (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:
PCVCR1
Register Description:
Path Code Violation Count Register 1
Register Address:
44h
Bit # 7 6 5 4 3 2 1 0
Name PCVC15 PCVC14 PCVC13 PCVC12 PCVC11 PCVC10 PCVC9 PCVC8
Default 0 0 0 0 0 0 0 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:
PCVCR2
Register Description:
Path Code Violation Count Register 2
Register Address:
45h
Bit # 7 6 5 4 3 2 1 0
Name PCVC7 PCVC6 PCVC5 PCVC4 PCVC3 PCVC2 PCVC1 PCVC0
Default 0 0 0 0 0 0 0 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.