XRT73L03 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT73L03' PDF : 62 Pages View PDF
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PRELIMINARY
3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT XRT73L03
REV. P1.0.13
FIGURE 32. THE XRT73L03 EMPLOYING THE TRANSMIT DRIVE MONITOR FEATURES
TTIP(n)
R1 = 31.6Ω
J1
BNC
TxPOS(n)
TxNEG(n)
TxLineClk(n)
TRing(n)
TPData(n)
TNData(n)
TxClk(n)
MTIP(n)
R3 = 270Ω
MRing(n)
Channel (n)
R4 = 270Ω
R2 = 31.6Ω 1:1
Only One Channel Shown
When the Transmit Drive Monitor circuitry in a given
line is connected to the line as illustrated in Figure 32,
then it monitors the line for transitions. As long as the
Transmit Drive Monitor circuitry detects transitions on
the line via the MTIP(n) and MRing(n) pins, it keeps
the DMO (Drive Monitor Output) signal "Low". How-
ever, if the Transmit Drive Monitor circuit detects no
transitions on the line for 128+32 TxClk periods, the
DMO (Drive Monitor Output) signal toggles "High".
NOTE: The Transmit Drive Monitor circuit does not have to
be used to operate the Transmit Section of the XRT73L03.
This is purely a diagnostic feature.
4.6 THE TAOS (TRANSMIT ALL ONES) FEATURE
The XRT73L03 can command any channel to trans-
mit an all “1’s” pattern onto the line by toggling a sin-
gle input pin or by setting a single bit-field in one of
the Command Registers to "1".
NOTE: When this feature is activated, the Transmit Section
of the configured channel in the XRT73L03 overwrites the
Terminal Equipment data with an all “1’s” pattern.
a. Operating in the Hardware Mode
Configure Channel(n) to transmit an all “1’s” pattern
by toggling the TAOS(n) input pin (pin 2, 85 or 84)
“High". Terminate the all “1’s” pattern by toggling the
TAOS(n) input pin "Low".
b. Operating in the HOST Mode
Configure Channel(n) to transmit an all “1’s” pattern
by writing to Command Register CR1-(n) and setting
the TAOS(n) bit-field (bit D3) to "1".
COMMAND REGISTER CR1-(N)
D4
D3
D2
D1
D0
TxOFF(n) TAOS(n) TxClkINV(n) TxLEV(n) TxBIN(n)
0
1
X
X
X
Terminate the all “1’s” pattern by writing to Command
Register CR1-(n) and setting the TAOS(n) bit-field
(D3) to "0".
5.0 THE MICROPROCESSOR SERIAL INTER-
FACE
The on-chip Command Registers of XRT73L03 DS3/
E3/STS-1 Line Interface Unit IC are used to configure
the XRT73L03 into a wide-variety of modes. This
section discusses the following:
1. The description of the Command Registers.
2. A description on how to use the Microprocessor
Serial Interface.
5.1 DESCRIPTION OF THE COMMAND REGISTERS
Table 2 lists the Command Registers, their Addresses
and their bit-formats.
50
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