
XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
PRELIMINARY
The Receive Data Link Source Select bits of the Receive Data Link Select Register (RDLSR) controls the des-
tination of R bits in T1DM framing format mode. The table below shows configuration of the Receive Data Link
Source Select bits of the Receive Data Link Select Register (RDLSR).
REV. P1.0.1
182
If the Receive Data Link Source Select bits of the Receive Data Link Select Register are set to 10, the Receive
Overhead Output Interface Block outputs the R bits extracted from the incoming T1 data stream. Since R bit
presents in Timeslot 24 of every T1DM frame, therefore, bandwidth of T1DM data link channel is 8KHz.
Figure 43 below shows the timing diagram of the output signals associated with the DS1 Receive Overhead
Output Interface module in T1DM framing format mode.
7.3
The XRT86L30 has the ability to extract or insert E1 data link information from or into the E1 National bit se-
quence. The source and destination of these inserted and extracted data link bits would be from either the in-
ternal HDLC Controller or the external device accessible through E1 Overhead Interface Block. The operation
of the Transmit Overhead Input Interface Block and the Receive Overhead Output Interface Block will be dis-
cussed separately.
7.4
E1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
B
LOCK
7.4.1
Description of the E1 Transmit Overhead Input Interface Block
The E1 Transmit Overhead Input Interface Block will allow an external device to be the provider of the E1 Na-
tional bit sequence. This interface provides interface signals and required interface timing to shift in proper data
link information at proper time.
E1 O
VERHEAD
I
NTERFACE
B
LOCK
RECEIVE DATA LINK SELECT REGISTER (RDLSR) (ADDRESS = 0X010AH)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
1-0
Receive Data Link
Source Select
R/W
00 - The extracted Facility Data Link bits are stored in either the LAPD controller
or the SLC
96 buffer. At the same time, the extracted Facility Data Link bits are
outputted from the framer through the Receive Serial Data Output Interface via
the RxSer_n pins.
01 - The extracted Facility Data Link bits are outputted from the framer through
the Receive Serial Data Output Interface via the RxSer_n pins.
10 - The extracted Facility Data Link bits are outputted from the framer through
the Receive Overhead Output Interface via the RxOH_n pins. At the same time,
the extracted Facility Data Link bits are outputted from the framer through the
Receive Serial Data Output Interface via the RxSer_n pins.
11 - The Facility Data Link bits are forced to one by the framer.
F
IGURE
43. DS1 R
ECEIVE
O
VERHEAD
O
UTPUT
I
NTERFACE
T
IMING
IN
T1DM F
RAMING
F
ORMAT
MODE