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XRT72L74
FOUR CHANNEL, DS3 ATM UNI/CLEAR-CHANNEL FRAMER
PRELIMINARY
REV. P1.0.0
61
T
ABLE
22:
R
X
DS3 LAPD S
TATUS
R
EGISTER
R
EGISTER
21 R
X
DS3 LAPD S
TATUS
R
EGISTER
H
EX
A
DDRESS
: 0
X
15
B
IT
F
UNCTION
T
YPE
D
EFAULT
D
ESCRIPTION
-O
PERATION
7
Unused
RO
0
6
Rx ABORT
RO
0
0: Indicates that the LAPD Receiver is NOT currently receiving an ABORT
Message.
1: Indicates that the LAPD Receiver is currently receiving an ABORT Mes-
sage.
N
OTE
:
This bit-field is only active if the XRT72L74 has been configured to
support the “C-bit Parity” Framing format.
5
Rx LAPD Type(0)
RO
0
00: LAPD Message is Test Signal Identification type. (RAM Depth is 76 bytes
(38 words))
01: LAPD Message is Idle Signal Identification type. (RAM Depth is 76 bytes
(38 words))
10: LAPD Message is CL Path Identification type. (RAM Depth is 76 bytes
(38 words))
11: LAPD Message is ITU-T Path Identification type. (RAM Depth is 82 bytes
(41 words))
N
OTE
:
These two bit-fields are only active if the XRT72L74 has been con-
figured to support the “C-bit Parity” Framing Format.
4
Rx LAPD Type(1)
RO
0
3
Rx CR Type
RO
0
0: Received LAPD message originated from customer installation
1: Received LAPD message originated from terminal in the network
N
OTE
:
This bit-field is only active if the XRT72L74 has been configured to
support the “C-bit Parity” Framing Format.
2
Rx FCS Error
RO
0
0: CRC-16 Error was NOT detected within the most recently received LAPD
Message.
1: CRC-16 Error was detected within the most recently received LAPD Mes-
sage.
N
OTE
:
This bit-field is only active if the XRT72L74 has been configured to
support the “C-bit Parity” Framing Format.
1
Rx End of Message
RO
0
0: Indicates that either the “Receive LAPD Message” Buffer is empty, or that
the LAPD Receiver is currently receiving a LAPD Message.
1: Indicates that a full LAPD Message has been received by the LAPD
Receiver and that this message is residing within the “Receive LAPD Mes-
sage” Buffer.
N
OTE
:
This bit-field is only active if the XRT72L74 has been configured to
support the “C-bit Parity” Framing Format.
0
Flag Present
RO
0
0: Indicates that the LAPD Receiver is NOT currently receiving the “Flag
Sequence”, within the LAPD Channel.
1: Indicates that the LAPD Receiver is currently receiving the “Flag
Sequence” within the LAPD Channel.
N
OTE
:
This bit-field is only active if the XRT72L74 has been configured to
support the “C-bit Parity” Framing Format.