XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. 1.0.1
TABLE 22: FRAMING
C
ONTROL
REGISTER E1 MODE
R
EGISTER 11 -- E1 MODE
F
RAMING
C
ONTROL EGISTER (FCR)
R
H
EX
ADDRESS: 0X010B
B
IT UNCTION
F
T
YPE
R/W
R/W
D
EFAULT
DESCRIPTION-OPERATION
4
3
CRCC(1)
CRCC(0)
0
0
Loss of CRC-4 Multiframe Alignment Criteria Select
Selects criteria for Loss of CRC-4 Multiframe Alignment.
00 = Four consecutive CRC Multiframe Alignment signals have been
received in error
01 = Two consecutive CRC Multiframe Alignment signals have been
received in error
10 = Eight consecutive CRC Multiframe Alignment signals have been
received in error
11 = 915 or more CRC-4 errors have been detected in one second.
NOTE: These bit-fields are ignored if CRC Multiframe Alignment has
been disabled.
2
1
0
FASC(2)
FASC(1)
FASC(0)
R/W
R/W
R/W
0
1
1
Loss of FAS Alignment Criteria Select
These three Read/Write bits are used to select Loss of FAS Frame
Declaration criteria. The relationship between the state of these bits
and the corresponding Loss of FAS Frame declaration is presented
below.
000 = Illegal - do not use
001 = 1 errored FAS pattern
010 = 2 consecutive errored FAS patterns
011 = 3 consecutive errored FAS patterns
100 = 4 consecutive errored FAS patterns
101 = 5 consecutive errored FAS patterns
110 = 6 consecutive errored FAS patterns
111 = 7 consecutive errored FAS patterns
TABLE 23: FRAMING
C
ONTROL
REGISTER T1 MODE
R
EGISTER 11 -- T1 MODE
F
RAMING
C
ONTROL EGISTER (FCR)
R
H
EX
ADDRESS: 0X010B
B
IT UNCTION
F
TYPE
D
EFAULT
DESCRIPTION-OPERATION
7
RSYNC
R/W
0
Force Re-Synchronization
A 0 to 1 transition in this bit-field forces the Receive DS1 Framer to
restart the synchronization process. This bit field is automatically
cleared (set to 0) after frame synchronization is reached.
6
CRCENB/
ONEONLY
R/W
0
Sync with CRC verification in ESF. (Assuming only one Ft sync can-
didate exists.)
0 = No CRC match test
1 = Include CRC match test as part of Synchronization criteria.
5
4
3
TOLR[2]
TOLR[1]
TOLR[0]
R/W
R/W
R/W
0
1
0
Tolerance Bits [2:0]
The Tolerance (TOLR) and Range (RANG) form the criteria for loss of
frame alignment. A loss of frame is declared if there is “TOLR out of
RANG” errors in the framing pattern. The recommended TOLR value
is 2.
NOTE: A “0” value for TOLR is internally blocked. A TOLR value must
be specified.
49
EXAR [ EXAR CORPORATION ]
