November 17, 2009 --Vitesse Semiconductor Corp. has released the VSC8238-02 EDC clock and data recovery (CDR) device, the newest member of its family of ICs featuring FlexEQ electronic dispersion compensation (EDC) technology. Vitesse says the VSC8238-02 is the industry's only CDR to meet the challenges of transmitting and recovering 8G Fibre Channel data in lossy legacy blade server backplanes and host bus adapters (HBA). The device is also backward compatible with 2G and 4G Fibre Channel for legacy backplane data rate upgrades.
With growing acceptance of Internet Protocol television (IPTV), video-on-demand (VoD), remote data storage, and server virtualization, data centers are doubling or quadrupling switching speed and data delivery by moving HBAs and blade servers to 8G Fibre Channel from 2G and 4G. The FlexEQ technology in the VSC8238-02 allows this upgrade at both the switch and HBA ends with high confidence of first-pass design success and wide performance margins, resulting in quick time-to-market and less equipment downtime once deployed, according to the developer.
"Vitesse's VSC8238-02 EDC CDR solution is taking the migration of legacy Fibre Channel storage hardware to a new level," claims Gary Paules, product marketing manager for Vitesse. "As the need to overcome bandwidth demands on the data center grows increasingly common, the ability to double or quadruple the data rate quickly and cost-efficiently has become imperative. Our new device provides field-proven 8G operation with unique backward compatibility to effectively address this critical technical challenge for the first time."
Exceeding the IEEE Long Range Multimode (LRM) requirement of 220 m and incorporating sophisticated feed-forward equalization (FFE) and decision feedback equalization (DFE) architecture, the VSC8238 exhibits performance margins in excess of 3 dB in relation to all LRM standard requirements. The same performance seen in optical transport applications is being applied to electrical backplane upgrades that are underway in many systems: 4G to 8G in Fibre Channel; 3G XAUI to 10G Ethernet; and 5G DDR to 10G QDR in InfiniBand.
The upgrades of legacy hardware must overcome high insertion losses, excessive signal crosstalk, degraded signal-to-noise ratios (SNRs), and significant signal reflections due to lossy PCBs and subrate connectors. Vitesse says the adaptive nature of the FlexEQ architecture allows it to compensate for widely disparate channels unlike simpler equalizer devices and operate in very poor noise environments below 20-dB SNR. The highly linear input automatic gain control (AGC) provides a constant signal level to the equalizer independent of the channel loss that can vary greatly from channel to channel and from one chassis generation to the next. The device provides in excess of 5UI of correction to resolve high-level signal reflections that can occur on the shorter channels of legacy platforms. Unlike DSP-based devices, the VSC8238-02 minimizes system latency critical to data center and storage applications.
In addition to supporting the data rate increase in a legacy low-speed platform, the need to continue supporting lower data rates is a critical requirement. Vitesse, together with QLogic and Emulex, both suppliers of high-performance network infrastructure equipment, have overcome this challenging auto-negotiation requirement via firmware development. As a result, the VSC8238-02 supports 2G, 4G, and 8G traffic with convergence times of 50 ms, well within the stringent 150-ms Fibre Channel requirement.
"Vitesse's VSC8238-02 EDC solution, together with QLogic's 8G Fibre Channel adapters, will enable storage vendors to quickly and cost-effectively migrate legacy 2G and 4G Fibre Channel systems to 8G," says Satish Lakshmanan, director of product marketing, Host Solutions Group, QLogic. "This solution enables our customer base to respond rapidly to increasing storage demands and maintain superior performance in virtualized environments with minimal impact to existing infrastructure."
"Vitesse collaborated closely with Emulex to ensure the transparent integration of Vitesse's VSC8238-02 EDC product with Emulex's recently announced LightPulse 8G Fibre Channel HBA CIOv expansion card," adds Clay Glenn, director of product marketing, Emulex Corp. "In addition to enabling 8G Fibre Channel operation on legacy server platforms, Emulex's collaboration with Vitesse allows Emulex 8G HBAs to support the stringent auto-negotiation requirements for 2G and 4G Fibre Channel operation, thus providing a seamless migration path for the equipment user."
The VSC8238XKP-02 is production released. Volume pricing is available upon request.