
XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.1
The Transmit Overhead Input Interface for a given Framer consists of two signals.
TxOHClk_n: The Transmit Overhead Input Interface Clock Output signal
TxOH_n: The Transmit Overhead Input Interface Input signal.
The Transmit Overhead Input Interface Clock Output pin (TxOHCLK_n) generates a rising clock edge for each
National bit that is configured to carry Data Link information according to setting of the framer. The Data Link
equipment interfaced to the Transmit Overhead Input Interface should update the data link bits on the TxOH_n
line upon detection of the rising edge of TxOHClk_n. The Transmit Overhead Input Interface block will sample
and latch the data link bits on the TxOH_n line on the falling edge of TxOHClk_n. The data link bits will be in-
cluded in and transmitted via the outgoing E1 frames.
The figure below shows block diagram of the DS1 Transmit Overhead Input Interface of XRT86L30.
PRELIMINARY
183
7.4.2
Sequence in E1 framing format mode
The National Bit Sequence in E1 framing format mode can be inserted from:
E1 Transmit Overhead Input Interface Block
E1 Transmit HDLC Controller
E1 Transmit Serial Input Interface
The purpose of the Transmit Overhead Input Interface is to permit Data Link equipment direct access to the
Sa4 through Sa8 National bits that are to be transported via the outbound frames. The Transmit Data Link
Source Select [1:0] bits, within the Synchronization MUX Register (SMR) determine source of the Sa4 through
Sa8 National bits to be inserted into the outgoing E1 frames.
The table below shows configuration of the Transmit Data Link Source Select [1:0] bits of the Synchronization
MUX Register (SMR).
Configure the E1 Transmit Overhead Input Interface module as source of the National Bit
If the Transmit Data Link Source Select bits of the Transmit Data Link Select Register are set to 10, the Trans-
mit Overhead Input Interface Block becomes input source of the FDL bits.
The XRT86L30 allows the user to decide on the following:
How many of the National Bits will be used to carry the Data Link information bits
F
IGURE
44. B
LOCK
D
IAGRAM
OF
THE
E1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
OF
XRT86L30
SYNCHRONIZATION MUX REGISTER (SMR) (ADDRESS = 0X0109H)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
3-2
Transmit Data Link
Source Select [1:0]
R/W
00 - The Sa4 through Sa8 National bits are inserted into the framer through the
Transmit Serial Data input Interface via the TxSer_n pins.
01 - The Sa4 through Sa8 National bits are inserted into the framer through the
Transmit LAPD Controller.
10 - The Sa4 through Sa8 National bits are inserted into the framer through the
Transmit Overhead Input Interface via the TxOH_n pins.
11 - The Sa4 through Sa8 National bits are inserted into the framer through the
Transmit Serial Data input Interface via the TxSer_n pins.
Transmit
Overhead Input
Interface
TxOH_n
TxOHClk_n
To Transmit
Framer Block