22
Agere Systems Inc.
TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
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 Supermapper 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 Supermapper 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
Symbol
Type
Path Overhead Access Channel (POAC)
—
O
Receive POAC Clock.
Receive side serial access channel
clock output for the path overhead bytes.
—
O
Receive POAC Data.
Receive side serial access channel
data output for the path overhead bytes.
—
O
Receive POAC Synchronization.
Receive side sync output
for POAC channel. Active-high during the last bit of the last
byte of the POAC frame.
—
O
Transmit POAC Clock.
Transmit side serial access chan-
nel clock output for the path overhead bytes.
—
I
Pull-down
data input for the path overhead bytes.
—
O
Transmit POAC Synchronization.
Transmit side sync out-
put for POAC channel. Active-high during the last bit of the
last byte.
I/O
Description
AE3
RPOACCLK
AD4
RPOACDATA
AF4
RPOACSYNC
AE4
TPOACCLK
AD5
TPOACDATA
Transmit POAC Data.
Transmit side serial access channel
AC5
TPOACSYNC
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.
AD6, AE6,
AC6
AUTO_AIS
—
I/O
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 an 8 kHz timing refer-
ence for network synchronization to the receive high-speed
data input (STS-3 or STS-1).
AD7
RHSFSYNCN
—
O
Table 6. TOAC and POAC
(continued)