XRT86VL38 Datasheet, PDF (35/180 Pages) Exar Corporation – OCTAL T1/E1/J1 FRAMER/LIU COMBO - E1 REGISTER DESCRIPTION

REV. P1.0.9
PRELIMINARY
XRT86VL38
OCTAL T1/E1/J1 FRAMER/LIU COMBO - E1 REGISTER DESCRIPTION
TABLE 10: FRAMING CONTROL REGISTER (FCR)
HEX ADDRESS: 0Xn10B
BIT
FUNCTION
TYPE DEFAULT
DESCRIPTION-OPERATION
7 Reframe
R/W
0
Force Reframe
A ‘0’ to ‘1’ transition will force the Receive E1 Framer to restart the syn-
chronization process. This bit field is automatically cleared (set to 0)
after frame synchronization is reached.
6-5 Loss of CAS MF
Align_Sel [1:0]
R/W
10 Loss of CAS Multiframe Alignment Defect Declaration Criteria
Select [1:0]
These two bits permit the user to select the “Loss of CAS Multiframe
Alignment” defect declaration criteria. Loss of CAS Multiframe Align-
ment defect is declared based on the number of consecutive CAS mul-
tiframes with Multiframe Alignment signal received in error as indicated
in the table below.
CASC[1:0]
LOSS OF CAS MULTIFRAME ALIGNMENT
DECLARATION CRITERIA
00
2 consecutive CAS Multiframes
01
3 consecutive CAS Multiframes
10
4 consecutive CAS Multiframes
11
8 consecutive CAS Multiframes
4-3 Loss of CRC Multi- R/W
frame Align_Sel[1:0]
NOTE: These bits are active only if CAS Multiframe Alignment is
enabled.
00 Loss of CRC-4 Multiframe Alignment Defect Declaration Criteria
Select [1:0]
These two bits permit the user to select the “Loss of CRC-4 Multiframe
Alignment” defect declaration criteria for the Channel. The following
table presents the different CRC-4 Multiframe Algorithms in terms of
the number of consecutive erred CRC-4 multiframe alignments that the
E1 Receiver Framer will receive before it declares the “Loss of CRC-4
Multiframe Alignment” defect condition.
CASC[1:0]
LOSS OF CRC-4 MULTIFRAME ALIGNMENT
DECLARATION CRITERIA
00
4 consecutive CRC-4 Multiframes Alignment
01
2 consecutive CRC-4 Multiframes Alignment
10
8 consecutive CRC-4 Multiframes Alignment
11
If TBR-4 Standard is Enabled*:
4 consecutive CRC-4 Multiframe Alignment or 915
or more CRC-4 errors
If TBR-4 Standard is Disabled*:
915 or more CRC-4 errors
NOTE: These bits are only active if CRC Multiframe Alignment is
enabled. If CRC multiframe alignment is not found in 8ms, the
E1 receive framer will restart the synchronization process.
NOTE: TBR-4 standard is enabled by writing to 0xn112, bit 6.
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