As more and more peripherals attach to computers via USB ports, vendors are racing to fill gaps in the spectrum of support products. Chips that trim size and power consumption are emerging this month, while software providers are making it easier for Linux systems to implement USB technology.
USB has become a standard way to attach mainstream products like cameras and keyboards to hosts, and itís also being used to power products as unusual as cup warmers and small lights. Currently, thereís a changeover from basic USB technology to USB2.0, which offers far higher speeds better suited to many of the new peripherals that use the connection technique. USB2.0 runs at up to 480 Mbits/second, far faster than the 12 Mbits/second peak rate of earlier USB products. Thatís a huge benefit for digital cameras and other products that move lots of data.
SMSC Corp of Hauppauge, NY (www.smsc.com/main/catalog/usbprods.html) is bringing this new version of USB to designers who want to add ports, unveiling what it says is the first two-port USB 2.0 controller chip. Itís designed for mobile products and other applications that need two ports but donít have the room or power budget for a four-port chip.
ďThis part is 44 to 80 % smaller than four-port chips. The four-port chips draw 240 to 500 mA, while weíre less than 200 mA,Ē says Steve Nelson, marketing vice president at SMSC Connectivity Solutions. SMSCís 36-pin USB2502 measures only 6 mm per side.
Nelson notes that some multi-function peripherals themselves require more than one USB port. ďWhen you have a product like a pen drive with a thumbprint reader, you need one hub for the USB drive and a second for the fingerprint reader,Ē he says. The part only costs $2 in quantities of 10,000, giving it another edge over more costly four-port ICs.
On the software side, Arabella Software of Northborough, MA, is addressing the growing move to Linux as well as to USB. (www.arabellasw.com/www/Motorola.htm)† The company is adding USB functionality to the Linux program used on the PowerQuicc line of communication processors from Freescale Semiconductor of Austin, TX, the Motorola operation thatís being spun out (http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=02VS0lXvDCJk19DKCb). The software handles both the device and host sides, freeing developers from the task of writing drivers.† Linux systems that use the PowerQuicc chips can easily add a single USB port to products using the software.
USB2.0 is expected to dominate shipments in just a few years as USB1.0 use declines.