Getting a solid product out the door quickly is more important than ever now, and incorporating a module in your design can help. Small modules are available for everything, from the 8-bit Rabbit 3000 in Rabbit Semiconductor's RCM3750 to a 32-bit X-scale processor in Kontron's X-board.
These modules can plug into dual-inline package sockets such as Netburner's 40-pin MOD5213 or standard single-inline memory-module sockets like Systronix's Java-based, TINI-compatible (Tiny Internet Network Interface) TStik2. You can even put Linux in a tiny package from Gumstix.
What do all these products have in common (other than some hands-on reviews in EiED Online at www.elecdesign.com)? They all provide a well-designed, well-tested platform you can use to build products quickly with minimal hardware design and support. That leaves more time for software development and design or for debugging your own hardware. In many instances, it's just a matter of adding connectors. Use batteries or an external power supply, and you can pull even more of the design right off the shelf.
Other benefits include the ability to provide an upgrade path to customers as well as significantly easier maintenance, since replacing a module often is as easy as pulling it and plugging in a new one.
However, the pinouts and layouts on modules tend to be consistent only within a vendor's product line. So, you'll need to choose your module wisely. Some product lines consist only of the processor modules, while others include a line of peripheral cards. Some use a stacking architecture like Gumstix, while others provide a simple bus-oriented solution like Systronix. Module-based development kits often let you get started on software work the same day you install the software. It's a great way to go.