Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > FPGAs/PLDs

Fast FPGA-based modules prototype logic on your PC

Posted: 24 Mar 2006 ?? ?Print Version ?Bookmark and Share

Keywords:HDK-0501 interactive logic development kit? Xilinx XC2S200E-6PQ208C? FPGA? Saelig? Alex Mendelsohn?

Hevday HDK-0501 Interactive Logic Development Kit

The Xilinx-based Hevday HDK-0501 Interactive Logic Development Kit, offered by Saelig, costs less than $500, but potentially could bring a lot more value to your bench. It could even be used in low-volume applications as an integral module of an OEM system.

Or, thanks to its Ethernet hooks, it could reside on a network where it might work as a remote monitoring and control module. The possibilities are endless.

Of course, the primary purpose for this tool is to develop logic. In that capacity, the complexity of a circuit-under-development is limited only by the capacity of its on-board FPGA. It's a Xilinx XC2S200E-6PQ208C.

The XC2S200E-6PQ208C device includes over 5,000 flip-flops plus logic for over 5,000 four-input combinational logic functions.

Program and run
In use, the kit lets you design with the ease of a visually interactive programmable logic controller program. That is, you can enter, display, run and pause your circuit program-like, with the hardware running at real speed.

All you need to do is power up this module from a suitable 5V source, and connect it to your PC. Your PC will need to clock a Pentium at least 500MHz, and run Windows 2000 or Windows XP Home or Professional.

In addition, you will need a 5V power supply that can deliver 700mA on peaks (500mA continuously). Voltage regulators on the module then provide a stiff 1.8V source for the FPGA core, as well as 3.3V for the FPGA I/O and other circuitry.

You'll also need to install Xilinx's ISE 6.1 (or higher) FPGA compiler. You can get a freebie copy of the Xilinx ISE WebPACK from Xilinx's Download Center on its Web site (along with a license).

Software in the background
Simpler, though less configurable, than Xilinx's software, the Xilinx compiler stays in the background during circuit compilation. As such, it's entirely transparent to you as a developer as you generate and run C++, C# or Java libraries for the PC to access the system's Logic Module independently.

The Hevday Logic Module, together with a TCP/IP communications card, comprises the hardware of the Interactive Logic system. The communications card is what puts the system on 10MHz or 100MHz TCP/IP networks, with IP addressing, etc.

Note that this system uses logic configured in the FPGA, not on a simulator. However, if you need a fast hardware-assisted behavioral simulator, the Interactive Logic system and a logic module can do the trick.

Design software
The Interactive Logic integrated design software lets you enter a synchronous logic circuit as a multi-level schematic and state machine-based design. You can use components from a built-in library, or define your own functions. You can also re-use definitions at will.

Your schematics, except for the top level one, automatically define symbols you can use on higher-level schematics. You can also customize them graphically, and have them display data from underlying schematics.

State diagrams also have automatically generated symbols for placement on higher-level schematics. Both schematics and state diagrams can be annotated with text and graphics.

Transparent VHDL
Once your circuitry is to your liking, the Interactive Logic software takes over, transparently translating your circuit into VHDL so it can be compiled into a bit pattern for configuring the module's FPGA. What's neat about this is that you don't need to either see or understand VHDL.

The Interactive Logic software takes care of all the settings and the multi-step process for the Logic Module's FPGA circuit compilation and configuration. The software also integrates the necessary data access circuits in the logic, keeps track of the data locations, maps the terminals on your schematic directly to Logic Module I/O pins, and handles data access in the background.

Compact hardware
On the hardware side, the Interactive Logic system provides all necessary circuitry for FPGA voltage regulation, de-coupling and power distribution, as well as clock generation and frequency selection.

You can therefore actually test your circuit at different speeds. The system also gives you everything you need for writing your configuration to flash. The hardware also provides for power-on reset and data access.

Communications cards
The aforementioned communications cards, also known by Hevday as comms cards, are of two kinds. Both comprise microcomputer systems with embedded TCP/IP stacks and software for controlling the Logic Module.

A development comms card supports all features of the Interactive Logic system that are required for circuit development. A lower cost Monitor comms card supports features designed for monitoring systems in operation.

Once your circuit is developed, the Logic Module itself can be used with or without a comms card. Without one, it loads your circuit from flash and runs it at a designated clock frequency at power-up.

The Logic Module hardware gives you 96 I/O pins. These are brought out to a half dozen 20-pin headers that provide 16 active I/O and four ground pins. Each LVTTL and 3V CMOS-compatible logic I/O pin can be an input, an output or can be bi-directional. 5V operation can also be supported.

A real-time view
You control the operation of the system's Logic Module by running, pausing, or single-stepping your circuit, and you can view circuit operation in real time, looking at signals and data while the circuit runs.

Signals and data are shown directly on the schematics, or they're shown as waveform displays. The neat part is that while the circuit runs, you can change signal levels and circuit data and set breakpoints.

A data display permits you to see waveform relationships at any level within a multi-level design on a clock-by-clock basis. For its part, a signal display records when signal transitions occur, rather than clock-by-clock data. The signal display lets you see relationships between signals over very long time-scales. Finally, a test manager lets you determine the maximum clock speed at which your circuit will run error-free.

- Alex Mendelsohn

Article Comments - Fast FPGA-based modules prototype lo...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top