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XRT94L43
153
SONET/SDH OC-12 TO 12XDS3/E3 MAPPER
REV. 1.0.2
STS-12/STM-4 TELECOM BUS INTERFACE - TRANSMIT DIRECTION
PIN #
SIGNAL NAME
I/O
SIGNAL
TYPE
DESCRIPTION
G2
TXA_CLK
O
CMOS
Transmit STS-12/STM-4 Telecom Bus Interface - Clock Signal:
This output clock signal functions as the clock source for the STS-12/
STM-4 Transmit Telecom Bus. All output signals (on the Transmit
STS-12/STM-4 Telecom Bus) are updated upon the rising edge of this
clock signal.
This clock signal operates at 77.76MHz and is derived from the Trans-
mit Clock Synthesizer block.
J1
TXA_C1J1
O
CMOS
STS-12/STM-4 Transmit Telecom Bus - C1/J1 Byte Phase Indicator
Output Signal:
This output pin pulses "High" under the following two conditions.
1. Whenever the C1 byte is being output via the TxA_D[7:0] output,
and
2. Whenever the J1 byte is being output via the TxA_D[7:0] output.
NOTES:
1.
The STS-12/STM-4 Transmit Telecom Bus will indicate that it
is transmitting the C1 byte (via the TXA_D[7:0] output pins),
by pulsing this output pin "High" (for one period of TXA_CLK)
and keeping the TXA_PL output pin pulled "Low".
2.
The STS-12/STM-4 Transmit Telecom Bus will indicate that it
is transmitting the J1 byte (via the TXA_D[7:0] output pins),
by pulsing this output pin "High" (for one period of TXA_CLK)
while the TXA_PL output pin is pulled "High".
3.
This output pin is only active if the STS-12/STM-4 Telecom
Bus is enabled.
J3
TXA_ALARM
O
CMOS
Transmit STS-12/STM-4 Telecom Bus - Alarm Indicator Output sig-
nal:
This output pin pulses "High", corresponding to any STS-1 signal (that
is being output via the TXA_D[7:0] output pins) is carrying the AIS-P
indicator.
This output pin is "Low" for all other conditions.
H1
TXA_DP
O
CMOS
STS-12/STM-4 Transmit Telecom Bus - Parity Output Pin:
This output pin can be configured to function as one of the following.
1. The EVEN or ODD parity value of the bits which are output via the
TXA_D[7:0] output pins.
2. The EVEN or ODD parity value of the bits which are being output via
the TXA_D[7:0] output pins and the states of the TXA_PL and
TXA_C1J1 output pins.
NOTE:
Any one of these configuration selections can be made by
writing the appropriate value into the Telecom Bus Control
Register (Indirect Address = 0x00, 0x37), (Direct Address =
0x0137)..