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XRT94L33
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
Rev.1.2.0.
71
C15
D21
AF13
RxOHENABLE_0
RxOHENABLE_1
RxOHENABLE_2
O
CMOS
Receive Overhead Data Output Interface – Enable Output
This output pin functions as the “Receive Overhead Enable”
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:
The channel will assert this output signal for one “RxOHClk_n”
period when it is safe for the local terminal equipment to
sample the data on the “RxOH_n” output pin.
When configured to operate in STS-1 mode:
These output pins, along with “RxOHClk_n”, “RxOHFrame_n”
and “RxOH_n” function as the “Receive STS-1 TOH and POH
Output Port”.
These output pins indicate whether POH or TOH data is being
output via the “RxOH_n” output pins.
These output pins will toggle “high” coincident with when POH
data
is
being
output
via
the
“RxOH_n”
output
pins.
Conversely, these output pins will toggle “l(fā)ow” coincident with
when TOH data is being output via the “RxOH_n” output pins.
These output pins are 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”.
D15
E20
AE13
RxOHCLK_0
RxOHCLK_1
RxOHCLK_2
O
CMOS
Receive Overhead Data Output Interface – clock
This output pin functions as the “Receive Overhead Clock”
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 Clock” output
when the device is configured to operate in the STS-1 mode.
When configured to operate in DS3/E3 mode:
The channel will output the overhead bits (within the incoming
DS3 or E3 frames) via the RxOH_n output pin, upon the falling
edge of this clock signal.
As a consequence, the user’s local terminal equipment should
use the rising edge of this clock signal to sample the data on
both the “RxOH” and “RxOHFrame” output pins.
Note:
This clock signal is always active.
When configured to operate in STS-1 mode:
These output pins, along with “RxOH_n”, “RxOHFrame_n”,
and “RxOHEnable_n” function as the “Receive STS-1 TOH
and POH Output Port”.
These output pins function as the “Clock Output” signals for
the Receive STS-1 TOH and POH Output Port.
The
“RxOH_n”, “RxSTS1Frame_n” and “RxOHEnable_n” output
pins are updated upon the falling edge of this clock signal.