[Technology Report]
Spring "Board" To FPGA Design Success
FPGA developmnent boards run the gamut from simple evaluation cards to application-targeted models that let you explore options.
Here's a tip for the next time you need to evaluate a new FPGA architecture or develop an application: Try an evaluation board or even a full-blown development kit. The basic resources these tools offer help chop away at product development time and cost.
Prices for basic starter kits range from about $50 to well over $2500. So, they're a good starting point for designers who are familiarizing themselves with an FPGA complex programmable logic device (CPLD) architecture and its capabilities. These tools also benefit designers who need a jumpstart in developing their application. Boards with multiple FPGAs and even full ASIC emulation systems are available for advanced development. Such boards typically range in price from a few thousand dollars to over $10,000.
Boards and kits come directly from FPGA suppliers like Actel, Altera, Atmel, Lattice, QuickLogic, and Xilinx. Distributors like Avnet and independent board and system suppliers like the Dini Group, GiDEL Ltd., Nallatech, SBS Technologies, and VMetro offer hardware tools that support the FPGAs.
Not to be overlooked is a host of CompactPCI CPU and support cards. Some of the suppliers of these cards target Advanced Telecommunications Architecture (ATCA) applications with boards that use multiple FPGAs. Such cards also could serve as development platforms for vertical market applications.
GETTING STARTED If you're new to the field and want some low-cost boards for insight into FPGA architecture and configuration techniques, try a starter development kit or budgetpriced evaluation board. These tools range from about $50 to about $400. They're usually pretty simple, containing the target FPGA or CPLD, a small breadboard area, a few indicators, and some connectors or tie points for I/O signals (Fig. 1).
Examples of these boards include the Twister card for the Altera Cyclone FPGA offered by Alearep B.V.; the LatticeEC evalution board standard version from Lattice Semiconductor; the Spartan 3 starter board from Xilinx partner Digilent; and Actel's Fusion starter kit. The many other low-cost evaluation and development boards on tap from FPGA suppliers and third-party vendors range from general-purpose platforms to application-targeted solutions.
The Twister card is optimized to explore the double-data-rate (DDR) synchronous DRAM interface available on the Altera Cyclone devices. For $349, the evaluation kit includes an EP1C6Q240C6 Cyclone FPGA and the DDR SDRAM controller core as a block of intellectual property (IP).
The latter can be loaded into the FPGA along with the rest of the logic you craft to evaluate the controller. The FPGA packs just under 6000 logic elements (about 120 kgates), 92 kbits of RAM, two phase-locked loops (PLLs), and up to 185 user I/O pins.
Supporting the Cyclone chip on the card are a 128-Mbit (8-Mword by 16-bit) DDR SDRAM, an 8-Mbit flash memory to hold configuration data, two daughterboard expansion interface headers (compatible with the Altera Nios proto headers), several user-configurable LED indicators and switches, an RS-232 serial port, and a JTAG test port. A preconfigured MAX-family CPLD on the board handles the configuration control functions. The card also ships with a DDR SDRAM reference design optimized to work with Altera's Nios configurable embedded processor.
Evaluation for $99? That's what the Digilent Spartan 3 starter board offers. This self-contained environment for the Xilinx Spartan 3 FPGA includes the XC3S200-FT256 Spartan 3 chip, 1 Mbyte of SRAM, 2 Mbits of configuration flash memory, eight slide switches, four pushbuttons, nine LEDs, and a four-digit seven-segment LED display. It additionally boasts three 40-pin expansion connectors, a serial port, a PS/2 mouse/keyboard port, and a VGA video port. The XC3S200 packs about 200 kgates, a dozen 18-bit multipliers, and 216 kbits of block RAM. Internal clock speeds reach 500 MHz.
To program the board, a JTAG3 programming cable as well as P4 and MultiPRO cables from Xilinx can tie the card to a PC or host system. The board is fully compatible with all versions of the Xilinx ISE tools, including the free WebPack version. Furthermore, it ships with the power supply and programming cable, so designs can be implemented with no hidden costs.
Unlike the Twister card, the Digilent card doesn't come with any IP or reference designs. Therefore, you'll need to develop the circuit functions or download the desired blocks of IP before you can configure the FPGA for evaluation.
Also ringing in at $99, the Lattice MachXO starter card comes replete with a download cable and power supply. Based around the LCMX0256C-4T100C FPGA, it includes status LEDs and eight I/O LEDs, an 8-bit input switch, a prototyping area, and a 33-MHz oscillator.
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