FPGAs aren’t that difficult to incorporate into embedded designs. But unlike some microcontrollers, they often lack features like built-in clocks and brownout detection. Also, some designs require offchip memory. One alternative is to employ an FPGA module that includes this additional circuitry.
Opal Kelly’s XEM3050 FPGA module contains a Xilinx Spartan-3 FPGA (see the figure). It also features a 1-Mbyte serial flash chip, a pair of independent 32-kbyte SDRAM chips, and a 2-Mbyte PROM. An 8-bit USB microcontroller provides programming and debug support. All it needs is a dc power source.
Also in the mix are inexpensive platforms such as DLP Design’s DLP-FPGA (see “Ready To Rock FPGA Development” at www.electronicdesign.com, ED Online 18270). The DLP-FPGA uses a Xilinx Spartan-3E along with an FTDI FT2232D USB interface.