
XRT84L38
424
OCTAL T1/E1/J1 FRAMER
REV. 1.0.1
The table below shows configuration of the LAPD Enable bit of the Data Link Control Register (DLCR).
DATA LINK CONTROL REGISTER (DLCR) (INDIRECT ADDRESS = 0XN0H, 0X13H)
14.1.2
How to configure XRT84L38 to transmit data link information through the National bits (Sa4
through Sa8)
As mentioned in previous section, the National bits (Sa4 through Sa8) of Timeslot 0 of non-FAS frame can be
used to transmit data link information in E1 mode.
The XRT84L38 allows the user to decide on the following:
Whether the National bits will be used to carry the data link information bits.
How many of the National Bits will be used to carry the Data Link information bits.
Which of these National Bits will be used to carry the Data Link information bits.
The Transmit Signaling and Data Link Control [2:0] bits of the Transmit Signaling and Data Link Select Register
(TSDLSR) determines if the National bits will be used to carry data link information. The table below shows
configuration of the Transmit Signaling and Data Link Control [2:0] bits of the Transmit Signaling and Data Link
Select Register (TSDLSR).
TRANSMIT SIGNALING AND DATA LINK SELECT REGISTER (TSDLSR) (INDIRECT ADDRESS =
0XN0H, 0X0AH)
If the Transmit Signaling and Data Link Select [2:0] bits of the Transmit Signaling and Data Link Select Register
is set to 000 or 001, the data link interface becomes source of the Sa4 through Sa8 National bits.
The Transmit Sa Data Link Select bits of the Transmit Signaling and Data Link Select Register (TSDLSR)
determine which ones of the National bits are configured as Data Link bits in E1 framing format mode.
Depending upon the configuration of the Transmit Signaling and Data Link Select Register, either of the
following cases may exists:
None of the National bits are used to transport the Data Link information bits (That is, data link channel of
XRT84L38 is inactive).
Any combination of between 1 and all 5 of the National bits can be selected to transport the Data Link
information bits.
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
0
LAPD Enable
R/W
0 - The Transmit HDLC Controller will send out Bit-Oriented Signaling
(BOS) message.
1 - The Transmit HDLC Controller will send out LAPD protocol or so-called
Message-Oriented Signaling (MOS) message.
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
2-0
Transmit Signaling
and Data Link
Select
R/W
000 - The data link interface is source of the Sa4 through Sa8 Nation bits.
001 - The data link interface is source of the Sa4 through Sa8 Nation bits.
010 - The Sa4 through Sa8 Nation bits are forced to 1.
011 - The Sa4 through Sa8 Nation bits are forced to 1.
1xx - The Sa4 through Sa8 Nation bits are forced to 1.