In its new IP3023 processor, Ubicom employs several unconventional techniques to reduce system cost, a critical factor in low-margin Soho networking equipment. Other processor vendors should consider similar techniques.

First, Ubicom implements al-most all networking functions in software instead of in fixed-function accelerators and hardwired MACs. As a rule, hardwired logic requires far fewer transistors than software to implement any given function. So how does Ubicom gain a cost advantage?

Like most communications pro-cessors, the IP3023 is designed for a variety of applications, including wired and wireless gateways and routers with DSL, cable or satellite uplinks. Other vendors add a set of hardwired MACs and accelerators to deal with all possible protocols. But in any particular system, much of this circuitry lies unused.

In Ubicom's approach, the processor needs to execute only the subset protocols required at any given time. Thus, a reasonably fast and efficient processor, using Ubicom's own multithreaded design, can replace an array of special hardware units. The end result is a flexible chip with a smaller die size than most competitive devices.

User-defined I/O

At the $10 to $15 price required in high-volume small-office, home-office applications, package size can be as much of a cost factor as die size. Ubicom's second innovation is user-defined I/O. For example, any of the IP3023's four Ethernet (MII) ports can also be configured as a Utopia port, simply by changing the software.

Finally, Ubicom also looked at system cost. Because most communications processors integrate all required networking functions with the processor, the most significant remaining cost component is often memory. Taking advantage of its lack of dedicated networking hardware, the IP3023 integrates 256-kbyte memory. Because Ubicom's proprietary RTOS requires less than 50 kbytes, this is often enough for the customer's application.

One downside is that Ubicom's proprietary architecture is not compatible with popular operating systems such as VxWorks or Linux, or with applications based on them. But customers that take the time to port their software will find a cost advantage here.

Linley Gwennap is founder and principal analyst of The Linley Group (www.linleygroup.com).

http://www.eet.com