XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. 1.0.1
If the Transmit Data Link Source Select bits of the Transmit Data Link Select Register are set to 10, the
Transmit 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
Which of these National Bits will be used to carry the Data Link information 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
XRT86L30 is inactive).
•
Any combination of between 1 and all 5 of the National bits can be selected to transport the Data Link
information bits.
The table below shows configuration of the Transmit Sa Data Link Select bits of the Transmit Signaling and
Data Link Select Register (TSDLSR).
TRANSMIT SIGNALING AND DATA LINK SELECT REGISTER (TSDLSR) (ADDRESS = 0X010AH)
B
IT
B
IT
N
AME
B
IT
TYPE
BIT DESCRIPTION
N
UMBER
7
Transmit Sa8 Data
Link Select
R/W
R/W
R/W
R/W
R/W
0 - Source of the Sa8 Nation bit is not from the data link interface.
1 - Source the Sa8 National bit from the data link interface.
6
5
4
3
Transmit Sa7 Data
Link Select
0 - Source of the Sa7 Nation bit is not from the data link interface.
1 - Source the Sa7 National bit from the data link interface.
Transmit Sa6 Data
Link Select
0 - Source of the Sa6 Nation bit is not from the data link interface.
1 - Source the Sa6 National bit from the data link interface.
Transmit Sa5 Data
Link Select
0 - Source of the Sa5 Nation bit is not from the data link interface.
1 - Source the Sa5 National bit from the data link interface.
Transmit Sa4 Data
Link Select
0 - Source of the Sa4 Nation bit is not from the data link interface.
1 - Source the Sa4 National bit from the data link interface.
For every Sa bit that is selected to carry Data Link information, the Transmit Overhead Input Interface will
supply a clock pulse, via the TxOHClk_n output pin, such that:
•
The Data Link equipment interfaced to the Transmit Overhead Input Interface should update the data on the
TxOH_n line upon detection of the rising edge of TxOHClk_n.
•
The Transmit Overhead Input Interface will sample and latch the data on the TxOH_n line on the falling edge
of TxOHClk_n.
179
EXAR [ EXAR CORPORATION ]
