23
Agere Systems Inc.
Data Sheet
June 2002
TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
3 Pin Information
(continued)
Table 8. DS3 Port
Pin
V22
Symbol
PHASEDETUP
Type
—
I/O
O
Description
Phase Detector Up.
Phase error signal out to external fil-
ter and VCXO. This output will generate an error signal
when the VCXO output is slower than the reference sig-
nal.
Phase Detector Down.
Phase error signal out to external
filter and VCXO. This output will generate an error signal
when the VCXO output is faster that the reference signal.
Positive Data Output.
Serial DS3 positive data out to
LIU when the DS3 output port is operating in dual-rail
mode. Nonreturn-to-zero DS3 data output when the DS3
output is operating in single-ended mode.
Negative Data Output.
Serial DS3 negative data output
to LIU when the DS3 port is operating in dual-rail mode.
In single-rail mode, this output is not used and may be left
unconnected.
DS3 Data Out Clock.
44.736 MHz DS3 clock input. If the
Supermapper is being used to map DS3 data to and from
STS-1, then this clock will be supplied by the external
VCXO that is associated with the DS3 clock recovery
PLL. In other DS3 modes (e.g., M13), this input will be
supplied by an external crystal oscillator, usually associ-
ated with a DS3 LIU. If the DS3 port is not used, this input
may be tied to ground or left open, since it is equipped
with an internal pulldown resistor.
Positive Data Input.
If the DS3 port is configured in dual-
rail mode, then this input is serial positive data from an
external DS3 LIU. If the DS3 port is configured in single-
rail mode, then this input is serial nonreturn-to-zero data
from the external LIU.
Negative Data In.
In dual-rail mode, this is negative data
from an external DS3 LIU. In single-rail mode, it may be
connected to the bipolar violation output of the external
DS3 LIU, left unconnected, or tied to ground.
DS3 Data In Clock.
This is a
44.736 MHz clock input
from the clock recovery in the external DS3 LIU.
U22
PHASEDETDOWN
—
O
R22
DS3POSDATAOUT
—
O
P22
DS3NEGDATAOUT
—
O
N22
DS3DATAOUTCLK
—
I
Pull-down
M22
DS3POSDATAIN
—
I
Pull-down
K22
DS3NEGDATAIN
—
I
Pull-down
J22
DS3DATAINCLK
—
I
Pull-down