
XRT94L43
156
REV. 1.0.2
SONET/SDH OC-12 TO 12XDS3/E3 MAPPER
STS-12/STM-4 TELECOM BUS INTERFACE - RECEIVE DIRECTION
PIN #
SIGNAL NAME
I/O
SIGNAL
TYPE
DESCRIPTION
V4
RxD_CLK
I
TTL
Receive STS-12/STM-4 Telecom Bus Interface - Clock Signal:
This input clock signal functions as the clock source for the Receive STS-
12/STM-4 Telecom Bus Interface. All Receive STS-12/STM-4 Telecom Bus
Interface signals are sampled upon the rising edge of this input clock sig-
nal.
This clock signal should operate at 77.76MHz.
NOTE: This input pin is only used if the STS-12/STM-4 Telecom Bus has
been enabled. It should be tied to GND otherwise.
U5
RxD_PL
I
TTL
Receive STS-12/STM-4 Telecom Bus Interface - Payload Indicator Sig-
nal:
This input pin indicates whether or not STS-1/STS-3c SPE bytes are being
input via the RXD_D[7:0] input pins.
This input pin should be pulled "High" coincident to whenever the Receive
STS-12/STM-4 Telecom Bus Interface block is receiving STS-1/STS-3c
SPE data bytes via the RXD_D[7:0] input pins.
Conversely, this input pin should be pulled "low" coincident to whenever
the Receive STS-12/STM-4 Telecom Bus Interface block is receiving
something other than an STS-1/STS-3c SPE byte (e.g., a TOH byte) via
the RXD_D[7:0] input pins.
NOTE: The user should tie this pin to GND if the STS-12/STM-4 Telecom
Bus Interface is configured to operate in the Re-Phase ON Mode
or is disabled.Tie this pin to GND if the STS-12/STM-4 Telecom
Bus is NOT enabled.
V2
RxD_C1J1
I
TTL
STS-12/STM-4 Receive Telecom Bus C1/J1 Byte Phase Indicator Input
Signal:
This input pin should be pulsed "High" during both of the following condi-
tions.
1. Whenever the C1 byte is being input to the Receive STS-12/STM-4 Tele-
com Bus Interface - Data Bus Input pins (RXD_D[7:0]).
2. Whenever the J1 byte is being input to the Receive STS-12/STM-4 Tele-
com Bus Interface - DataBus Input pins (RXD_D[7:0]).
This input pin should be pulled "low" for all other times.
NOTE:
Tie this pin to GND if the STS-12/STM-4 Telecom Bus is NOT
enabled.