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greenpowerZONE Products for the week of April 14, 2008
Vitesse Semiconductor Says…
Energy-Efficient Solutions For Ethernet-Based Electronics
Advanced functionality in the Vitesse SimpliPHY, SparX, and G-RocX Ethernet IC families help to eliminate 80% of unnecessary energy consumption
Networking equipment suppliers wanting to promote green electronics portfolios can activate compelling, energy-efficient functionality within their Ethernet-based electronics via a simple software upgrade available today from Vitesse Semiconductor Corporation . Vitesse is the first Ethernet silicon supplier to deliver energy saving features of up to 80-percent when fully linked-down compared to 1000BASE-T full data rate in network infrastructure devices or consumer premise equipment designed using its widely-adopted SimpliPHY, SparX, and G-RocX IC solutions.
Delivering green savings equivalent to well over 400mW per port, all three of Vitesse’s Ethernet IC product families are enhanced with two advanced, energy savings technologies. The first is ActiPHY , an automatic power savings mode that can detect unused Ethernet ports on network devices and power them down or place them in stand-by mode. The second is PerfectReach , an intelligent algorithm that actively adjusts the power level needed based on cable length. Both of these features are already integrated into all SimpliPHY, SparX, and G-RocX devices currently in mass production and can be enabled via an eco-friendly software upgrade.
New Functionality Bridges Industry Specifications
IEEE802.3 inefficiently specified that Ethernet products, when auto-negotiation is enabled, will never achieve an acceptable standby power level whenever a link is not established. A physical layer Ethernet port with ActiPHY enabled, however, will detect link loss and put the port into a sleep state, thereby reducing the port’s power well over 400mW. Using a proprietary energy detection circuit to filter random cable noise, ActiPHY detects the presence of link pulses, restores active power and puts the port back into normal operation. To ensure maximum interoperability when plugged into another Ethernet PHY with sleep capability, the device will wake up at a programmable rate and send a few link pulses to allow another sleeping device the opportunity to wake-up.
PerfectReach is an intelligent algorithm that actively adjusts the power level needed based on cable length. IEEE802.3 Ethernet specifies 10/100/1000BASE-T copper PHYs to operate at 100 meters. The standard also expects these same PHYs to communicate at its maximum power cable reach even if it is plugged into a cable that can be as short as a single meter. A Vitesse Gigabit Ethernet PHY with PerfectReach enabled will detect the presence of a shorter cable and then adaptively lower the power level, saving energy that would have been needed to attain a full 100 meters of cable length.
Ethernet OEMs Promoting Green Technology
Broaden public awareness, surge in network usage and adoption of global legislation has brought about increased demand for network equipment that operates more efficiently and delivers a positive impact for businesses, consumers and the environment. Several OEMs are now answering the call by delivering products to this emerging green-conscious customer segment by incorporating Vitesse’s ActiPHY and PerfectReach technology.
D-Link Systems, Inc. now offers Gigabit Home/SOHO switch products that not only comply with RoHS (Restriction of Hazardous Substances), but are the first to achieve energy efficiency. “Our environmentally friendly products have enabled eco-conscious customers to embrace and benefit from green concepts with regard to their connectivity,” said A.J. Wang, CTO for D-Link Systems, Inc. “In a standard workday scenario, PCs are used for 10 hours a day, powered off for 14, and connected to a switch using 20 meter cables. D-Link’s Green Ethernet on 8-, 16-, and 24-port switch products, powered by Vitesse’s SparX products with ActiPHY and PerfectReach technologies, helped us bring to market the industry’s first Green Ethernet 8-port 10/100/1000BASE-T desktop switch that achieves power savings of up to 80-percent.”
Corega, a global computer networking manufacturer, promotes greener practices as an organization and within the solutions it delivers. “In our original switching products, an IEEE 802.3 Ethernet-compliant device that had no ports connected to a link still consumed nearly the comparable amount of power as a fully-utilized switch,” said Sho Katoh, president of Corega. “By simply enabling Vitesse’s ActiPHY automatic link down power savings technology via software, we are now able to save our customers a maximum of 65.8% of electric power in the presence of unused Ethernet ports.”
EN-Genius Says…
Vitesse’s updated drivers for their GbE PHYs are notable because they are a zero-cost upgrade that lets any piece of equipment using their parts trim its energy consumption without any sacrifice in performance. No, this little piece of firmware is not going to single-handedly save the planet from a greenhouse gas-induced meltdown, but it is a good first step towards taking a chunk out of the 97 TW-hr that the US Department of Energy says that the computers, servers, routers and other enterprise-class IT equipment consumed in the US in 2002. Besides being a welcome interim solution until the IEEE 802.3az task force finalizes its so-called Energy-Efficient Ethernet spec a year or so from now, these upgrades are an instant value-add feature that helps distinguish Vitesse products from competitors in a near-commodity-level market.
These changes can be made to new and existing products thanks to the high degree of programmability afforded by Vitesse PHYs, (derived from the GbE technology they got when they acquired Cicada a few years back). The transceivers use a DSP-oriented approach to dealing with the line impairments associated with UTP copper – an approach that’s already given them some of the best reach and power consumption figures in the industry. By using some of the transceiver’s existing control registers to monitor line conditions and adjust its operating parameters on the fly, the new software can turn down, or turn off, whatever’s not needed at any particular time.
The first part of the upgrade is the ActiPHY function which allows an unused port to enter a sleep/stand-by mode that reduces its power consumption by around 75%. It takes advantage of the existing auto-negotiate sequence already used in all GbE devices to invoke the sleep mode if the link pulses it expects to see are not detected. Once asleep, the port wakes up intermittently to see if there is a link pulse on the line, a sign that it needs to come out of hibernation and put the transceiver back into operation.
The ActiPHY software works both when the cable is physically unplugged and when the device on the other end is turned off. Vitesse says that the driver works equally well with PCs, servers, and managed or unmanaged switches, even when the other end of the connection is not Vitesse silicon or running the ActiPHY firmware. The software even works on SimpliPHY devices with a fiber media port. This is about as good as it gets until the 802.3az standard is ready to implement the handshaking required to support a true idle mode.
Vitesse's PerfectReach smart cable reach algorithm is the second half of the solution: a short piece of code that allows the transmitter to adjust its power based on the length and quality of the cable it sees on the end of the connector. Rather than run at signal strength, and turn on all the equalization, and NEXT/FEXT/echo cancellation needed to reliably operate on a worst-case, maximum-length cable, the host-based algorithm uses the PHY DSP capabilities to probe the cable characteristics and length and then adjust both the transmit power and signal processing resources. According to Vitesse, this can shave about 10% power off an operating PHY in a typical application.
The software itself is pretty compact, comprising around 100 lines of C code, and runs on either the chip itself or a nearby host processor. For Vitesse one-chip L2 switches and L2/L3 routers, the new code resides in their internal VCore processors which, depending on product line, are either based on a souped-up 8051 or ARM-9 architecture. Applications using their SimpliPHY, standalone Copper PHYs, store the PHY management software in whatever processor or microcontroller is closest to them. Vitesse says the software is actually very minimal as most of the functionality is already embedded within the PHY, and that the routines consume very little of even the most modest controller processing power.
Existing switch and router designs can be upgraded using a set of turnkey drivers whose binary files may be blown onto the unit Flash or EEPROM memory. New customers using Vitesse L2 switch family can also use this turnkey code. For the more ambitious developers who want to add custom functionality Vitesse also provides an API code set consisting of raw ANSI C compatible libraries that a customer can compile themselves for their own application. The energy-saving features are now incorporated into their SDK package which includes a set of compiled code specific to an operating system (like Linux or VxWorks). This is probably overkill for small consumer products but very handy for adding value to core and stackable switches which use their bigger switches as or raw PHYs.
Together, the two software upgrades are estimated to enable 65% to 85% system power savings over conventional switches (with all ports inactive). Vitesse tests show that an unmanaged 8-port switch using their VSC7388 integrated switch/PHY can deliver up to 80% power savings. Their managed switches deliver slightly lower savings, thanks to the static power consumption of other components (additional memories, PHYs for USBs, VoIP, etc). The actual power-savings in higher-end routers is mostly a function of how many ports they contain but Vitesse estimates that a fully loaded system with several dozen ports could save 30 - 50%.
This should go along way towards helping designers meet the emerging energy efficiency standards being developed by EnergyStar for servers, PCs displays, and networking equipment. Besides the obvious environmental benefits, certification could prove to be a real market advantage with the growing numbers of eco-conscious consumers who look for the EnergyStar label on the things they purchase. Hopefully, this will also serve as a challenge that drives Broadcom and Marvell to put some of their best minds to work on achieving similar power savings in their PHYs, integrated switches, and other networking products.
The ActiPHY and PerfectReach software upgrades are available at no charge for Vitesse SimpliPHY 1000BT copper transceivers, SparX Layer 2 Gigabit switching platforms, and G-RocX Gigabit routing solutions. The ANSI C implementation of the API for the Vitesse PHY (Version 2.42) may be obtained from their web site as a .zip file. The download link can be found on any of the main product pages for their Copper PHY (products such as the VSC8664). The turnkey binary implementation for SparX and G-RocX is also available from Vitesse on the appropriate product pages. Vitesse says that they will be loading a standard package on their website shortly after this review is published.
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