Altera Stratix GX Transceiver - Manual (Page 83)

Altera Corporation 4–1
January 2005
4. SONET Mode
Introduction One of the most common serial backplanes in the communications or
telecom area is the SONET/SDH interface. For SONET/SDH
applications the synchronous transport signal STS-48 and Synchronous
Transport Module -16 (STM -16) are becoming popular SONET
backplanes.
Transceiver blocks provide an implementation of SONET/SDH
backplanes. The serial data range over 40'' of FR4 printed circuit board
support a STS-12/STS-48 and STS-192 standards data range. You can
implement many functions associated with SONET/SDH processing.
SONET/SDH backplanes are not designed to a specific standard because
different telecom manufacturers have developed their own proprietary
buses. The backplane transceiver in a SONET/SDH application requires
two types of features: protocol-specific functions and electrical features.
Transceiver blocks provide both of these features to a limited extent. One
example is the protocol feature using A1A2 or A1A1A2A2 for word
alignment.
SONET mode supports a subset of the transceiver blocks to allow for
customizable configuration. The channel aligner, rate matcher, and the
8B/10B encoder/decoder features are not available in this mode. This
chapter describes the supported digital architecture, clocking schemes,
and software implementation in SONET mode.
Figure 4–1 shows a block
diagram of a transceiver channel configured in SONET mode.
Stratix ® GX devices offer the following SONET/SDH features:
■ Serial data rate range from 614 Mbps to 3.1875 Gbps (non-encoded)
■ Input reference clock range from 38.375 to 650 MHz
■ Supports parallel interface width of 8 or 16 bits
■ Word aligner supports 16-bit or bit-slip mode