XRT73R12_07 Datasheet, PDF (77/89 Pages) Exar Corporation – TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT

REV. 1.0.2
XRT73R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
TABLE 35: TRANSMIT CONTROL REGISTER - CHANNEL N ADDRESS LOCATION = 0XM4
(N = [0:11] & M= 0-5 & 8-D)
BIT NUMBER
NAME
TYPE
DESCRIPTION
2
TAOS
R/W Transmit All OneS Pattern - Channel_n:
This READ/WRITE bit-field is used to command the Transmit Section of
Channel_n to generate and transmit an unframed, All Ones pattern via the
DS3, E3 or STS-1 line signal (to the remote terminal equipment).
Whenever the user implements this configuration setting, the Transmit Sec-
tion will ignore the data that it is accepting from the System-side equipment
and output the "All Ones" Pattern.
0 - Configures the Transmit Section to transmit the data that it accepts from
the System-side Interface.
1 - Configures the Transmit Section to generate and transmit the Unframed,
All Ones pattern.
1
TxCLKINV
R/W Transmit Clock Invert Select - Channel_n:
This READ/WRITE bit-field is used to select the edge of the TxCLK_n input
that the Transmit Section of Channel_n will use to sample the TxPOS_n and
TxNEG_n input pins, as described below.
0 - Configures the Transmit Section (within the corresponding channel) to
sample the TxPOS_n and TxNEG_n input pins upon the falling edge of
TxCLK_n.
1 - Configures the Transmit Section (within the corresponding channel) to
sample the TxPOS_n and TxNEG_n input pins upon the rising edge of
TxCLK_n.
NOTE: This is done on a per-channel basis.
0
TxLEV
R/W Transmit Line Build-Out Select - Channel_n:
This READ/WRITE bit-field is used to enable or disable the Transmit Line
Build-Out (e.g., pulse-shaping) circuit within the corresponding channel.
The user should set this bit-field to either "0" or to "1" based upon the follow-
ing guidelines.
0 - If the cable length between the Transmit Output (of the corresponding
Channel) and the DSX-3/STSX-1 location is 225 feet or less.
1 - If the cable length between the Transmit Output (of the corresponding
Channel) and the DSX-3/STSX-1 location is more than 225 feet .
The user must follow these guidelines in order to insure that the Transmit
Section (of Channel_n) will always generate a DS3 pulse that complies with
the Isolated Pulse Template requirements per Bellcore GR-499-CORE, or
an STS-1 pulse that complies with the Pulse Template requirements per Tel-
cordia GR-253-CORE.
NOTE: This bit-field is ignored if the channel has been configured to operate
in the E3 Mode.
74