Altera Stratix - System Topology

Altera Corporation 9–3
July 2005 Stratix Device Handbook, Volume 2
Implementing SFI-4 in Stratix & Stratix GX Devices
Figure 9–2. SONET/SDH Line Card
The OIF has defined the electrical interface (SFI) between the
SONET/SDH framer and high-speed SERDES devices. To keep up with
evolving transmission speeds and technology enhancements, different
versions of electrical interfaces are defined. SFI-4 is the version of SFI that
acts as an interface between an OC-192 SERDES and SONET framer, as
shown in Figure 9–2. An aggregate of 9953.28 Mbps is transferred in each
direction. With their differential I/O capabilities, Stratix and Stratix GX
devices are ideally suited to support the framer side of the SFI-4 interface.
Support for SFI-4 extends the reach of high-density programmable logic
from the backplane to the PHY devices.
System Topology
The SFI-4 interface uses 16 channels of source-synchronous LVDS to
interface between a SONET framer and an OC-192 SERDES. Figure 9–3
shows the SFI-4 interface.
CDR
OE Module
SONET/SDH
Mapper/Protocol
Processor
SONET/SDH
Framer
SERDES
Optical
Signal
SERDES Framer
Interface
Optical-Electrical
Conversion
Link Layer
Interface
To Packet
Processor &
Switch Fabri
c
7
65
4
312