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Preliminary Data Sheet, Rev. 1
October 2000
TMXF28155 Super Mapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
91
Lucent Technologies Inc.
TMUX Functional Description
(continued)
TMUX Transmit Path Overview
The TMUX transmit path is depicted in the top half of Figure 16, Detailed Block Diagram of the TMUX on page 94.
The transmit path of the TMUX implements the inverse function to the receive path. Transmit input traffic at the
telecom bus interface from up to three STS-1/TUG-3 paths is managed via the transmit path bus control circuitry.
Transmit traffic, alarms, or unequipped indication information is inserted as needed depending on the status and
provisioning of the device. The 3:1 multiplexer provides byte interleave multiplexing of the incoming traffic and
insertion of the path overhead bytes. A serial path provides input for the transmit protection traffic and the framer
and serial-to-parallel converter formats this traffic for input to the transmit MSP 1+1 payload switch. The selected
output from the transmit MSP 1+1 switch is input to the transport overhead insert block and the parallel to serial
converter sends a serial stream to the device output. The TMUX transmit path provides path overhead byte inser-
tion and transport overhead byte insertion via the respective POAC insert and TOAC insert interfaces.
Local clock and frame generation control circuitry is implemented in the TMUX for controlling the STS-1, STS-3
and STM-1 termination and generation functions. Internal loopbacks in the TMUX provide near-end line loopback
and far-end line loopback capability.
Transmit Telecom Bus
The transmit side of super mapper drives a clock and three sync signals (SPE, J0J1V1, and V1) onto the telecom
bus. These signals control when the internal SPE mapper or one of the mate devices talks on the data bus. As it is
on the receive side, the transmit telecom bus operates at 19.44 MHz for STS-3/STM-1 modes and at 6.48 MHz for
STS-1 mode. The TMUX communicates with up to three VT/VC mappers via an 8-bit data word and an odd/even
parity bit from the telecom bus. The data consists of the STS-1/TUG-3 from up to three mappers; each in its own
time slot, or it carries one single STS-1 signal. A 51.84 MHz low-speed clock and sync are also output.
Transmit High Order Path Overhead Generation and TPOAC Insert.
In the transmit direction, J1 path trace
byte insertion, B3 byte calculation and insertion, C2 signal label byte insertion, REI-P and RDI-P insertion; F2 byte
insertion, H4 multiframe byte insertion, F3 path user byte insertion, K3 byte insertion, N1 byte insertion, and AIS-P
insertion via POAC or software control is supported. The transmit TPOAC allows insertion of all overhead bytes
other than the B3 byte which is automatically calculated. Even or odd parity is checked over all bytes. Bytes which
are not enabled for insertion are set to an all-ones or all-zeros stuff value. Transport path overhead bytes are
added to the payload stream during multiplexing in the byte interleave multiplexer.
Transmit Byte Interleave Multiplexer.
In STS-3/STM-1 mode, the transmit byte interleave multiplexer block mul-
tiplexes up to three STS-1/TUG3 signals to form a SONET/SDH STS-3/STM-1 structured signal. The STS-3/STM-
1 multiplexer function processes the input bytes in the order in which they are presented on the transmit telecom
bus and multiplexes these bytes into a single high-speed stream. Grooming of the VTs/VCs is performed in the
SPE mapper of each of the three devices. High-order path overhead bytes are interleaved with the data traffic dur-
ing the byte interleave multiplexing.
Transmit Payload Framer and MSP 1+1 Payload Switch.
In the transmit direction, the MSP 1+1 switch function
incorporates dual MSP 1+1 payload switch structures. In operation, the traffic from the transmit byte interleave
multiplexer are presented to both MSP 1+1 payload switches. The output of the signal from the 3:1 multiplex is
broadcast to both switch paths and the output of the receive payload framers is also input respectively to one of the
two switch paths. For normal operation one of the two outputs from the two MSP 1+1 blocks is selected. The path
from the receive framer to the MSP switch structures provides a means to perform far end loopback.