xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 38

• Manufacturer Part Number: xrt94l33
• Description: Multi-channel, Multi-function Device Aggregates 3 Ds3/e3/sts-1 Into Oc3/stm-1
• Manufacturer: Exar Corporation

XRT94L33
Rev.1.2.0.
AG19
F12
B19
TxOHINS_0
TxOHINS_1
TxOHINS_2
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
I
TTL
Transmit Overhead Data Insert Input:
This input pin functions as the “Transmit Overhead Data
Insert” input indicator for the transmit system side interface
when the XRT94L33 is configured to operate in STS-1/DS3/E3
mode, however, it functions as the “Transmit STS-1 Overhead
Enable” output when the device is configured to operate in the
STS-1 mode.
When configured to operate in DS3/E3 mode:
This input pin permits the user to either enable or disable the
“Transmit Overhead Data Input Interface” block within the
DS3/E3 Frame Generator block.
If the Transmit Overhead Data Input Interface block is
enabled, then the DS3/E3 Frame Generator block will accept
overhead data (from the local terminal equipment) via the
“TxOH_n” input pin; and insert this data into the overhead bit
positions within the outbound DS3 or E3 data stream.
Conversely, if the Transmit Overhead Data Input Interface
block is disabled, then the DS3/E3 Frame Generator block it
will NOT accept overhead data from the local terminal
equipment.
Pulling this input pin “high” enables the “Transmit Overhead
Data Input Interface” block.
disables the “Transmit Overhead Data Input Interface” block
When configured to operate in STS-1 mode:
These input pins, along with “TxOH_n”, “TxOHEnable_n”,
“TxOHFrame_n” and “TxOHClk_n” function as the “Transmit
Overhead (TxOH) Input Port.
These input pins permit the user to enable or disable the
“TxOH” input port.
If these input pins are pulled “high”, then the “TxOH” port will
sample and latch data via the corresponding “TxOH” input
pins, upon the falling edge of “TxOHClk_n”.
Conversely, if these input pins are pulled “low”, then the
“TxOH” port will NOT sample and latch data via the
corresponding “TxOH” input pins.
Note:
38
If the “TxOHIns_n” input pin is pulled “LOW”, this
setting will be overridden if the user has configured
the “Transmit SONET/STS-1 POH Processor” or
“Transmit STS-1 TOH Processor” blocks to accept
certain POH or TOH overhead bytes via the external
port.
Pulling this input pin “low”
xr