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【应用手册】Implementing SFI-4 in Stratix & Stratix GX Devices
The growth of the Internet has created huge bandwidth demands as
voice, video, and data push the limits of the existing wide area network
(WAN) backbones. To facilitate this bandwidth growth, speeds of OC-192
and higher are being deployed in WAN backbones (see Figure 9–1).
Today’s carrier backbone networks are supported by SONET/SDH
transmission technology. SONET/SDH is a transmission technology for
transporting optical signals at speeds ranging from 51 megabits per
second (Mbps) up to 40 gigabits per second (Gbps). SONET/SDH rings
make up the majority of the existing backbone infrastructure of the
Internet and the public switched telephone network (PSTN).
The Optical Internetworking Forum (OIF) standard SFI-4 is a 16-bit LVDS
interface used in an OC-192 SONET system to link the framer and the
serializer/deserializer (SERDES). Stratix® and Stratix GX devices support
the required data rates of up to 622.08 Mbps along with the one-to-one
relationship required between clock frequency and data rate. The fast
phase-locked loop (PLL) was designed to support the high clock
frequencies and the one-to-one relationship (between clock and data rate)
needed for interfaces such as XSBI and SFI-4. Support for SFI-4 extends
the reach of high-density programmable logic from the backplane to the
physical layer (PHY) devices.
ch_11_vol_2(Replaces AN219).pdf
This chapter focuses on the implementation of the interface between the
SERDES and the framer.