
20
Agere Systems Inc.
TMXF28155 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Preliminary Data Sheet
May 2001
3 Pin Information
(continued)
3.3.5 Miscellaneous Signals
Table 7. Miscellaneous Signals
3.3.6 DS3 Port
If a DS3 output is required in a Super Mapper application and the DS3 signal has been recovered (demapped) from
an STS-1, then it is necessary to smooth the DS3 recovered clock. The DS3 clock extracted from the STS-1 clock
will have considerable jitter introduced when the SONET overhead is removed and pointer adjustments are made.
A phase locked loop is recommended for this purpose. The Super Mapper contains a phase comparator, that can
be used in conjunction with an external low-pass filter and voltage controlled crystal oscillator to implement the
PLL.
Pin
AF4
Symbol
RPOACSYNC
Type
—
I/O
O
Description
Receive POAC Synchronization.
Receive side sync output
for POAC channel. Active-high during the last bit of the last
byte of the POAC frame.
Transmit POAC Clock.
Transmit side serial access channel
clock output for the path overhead bytes.
Transmit POAC Data.
Transmit side serial access channel
data input for the path overhead bytes.
AE4
TPOACCLK
—
O
AD5
TPOACDATA
—
I
Pull down
O
AC5
TPOACSYNC
—
Transmit POAC Synchronization.
Transmit side sync out-
put for POAC channel. Active-high during the last bit of the
last byte.
Pin
AE5
Symbol
LOSEXT
Type
—
I/O
I
Description
Pull up
Loss of Signal External.
External loss of signal input. If
external clock and data recovery is used on the high-speed
I/O port, it may be connected to this input which can be con-
figured to assert the LOS register bit normally associated
with the internal LOS detection in the internal CDR block. The
polarity of LOS may be programmed active-high or low.
AIS Enable (3:1).
Control signal for automatic AIS insertion
on each STS1. The STS-1 AIS is applied down stream on the
telecom bus, i.e., it is an output from masters and an input to
slaves. Active-high.
Input when slave mode.
Output when master mode
If not used, leave open.
Receive High-speed Frame Synchronization.
Receive side
frame sync output indicating the frame location of the high-
speed data input. May be used as a 8 kHz timing reference
for network synchronization to the receive high-speed data
input (STS-3 or STS-1).
AD6, AE6,
AC6
AUTO_AIS
—
I/O
AD7
RHSFSYNCN
—
O
Table 6. TOAC and POAC
(continued)