xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 70

• 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.
AG13
C23
B15
RxOH_0
RxOH_1
RxOH_2
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
O
CMOS
Receive Overhead Data Output Interface – output
This output pin functions as the “Receive Overhead Data”
output for the receive system side interface when the
XRT94L33 is configured to operate in DS3/E3 mode, however,
it functions as the “Receive STS-1 Overhead Data” output
when the device is configured to operate in the STS-1 mode.
When configured to operate in DS3/E3 mode:
All overhead bits, which are received via the “Receive Section”
of the channel, will be output via this output pin, upon the
rising edge of “RxOHClk_n”.
When configured to operate in STS-1 mode:
These output pins, along with “RxOHEnable_n”, “RxOHClk_n”
and “RxOHFrame_n” function as the “Receive STS-1 TOH and
POH Output Port”.
Each bit, within the TOH and POH bytes (within the incoming
STS-1 data stream) is updated upon the falling edge of
“RxOHClk_n”. As a consequence, external circuitry receiving
this data, should sample this data upon the rising edge of
“RxOHClk_n”.
Notes:
1.
2.
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The external circuitry can determine whether or not it is
receiving POH or TOH data via this output pin.
“RxOHEnable_n” output pin will be “high” anytime POH
data is being output via these output pins. Conversely,
the “RxOHEnable_n” output pin will be “low” anytime TOH
data is being output via these output pins.
TOH and POH data, associated with Receive STS-1 TOH
and POH Processor Block – Channel 0 will be output via
the “RxOH_0, and so on.
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The