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Xilinx Software

Once you have a working simulation of your Triscuit implemented in Xilinx xc3000 parts, you need to run some software from Xilinx to translate that circuit into the internal data format of the Xilinx part itself so that the actual part can be programmed and used in your circuit. I've encapsulated all the required commands into a shell script that you can run on your finished and simulated design. Note that the design must be finished before you run the Xilinx software. That is, you must have put all the Xilinx-gates in a hierarchy that is rooted in a single Xilinx schematic and symbol. Note that this does not mean that all your circuits have to be on the same page! It does mean that the tree of schematics that make up your Triscuit must all start from a single schematic and then fan out from there. If the top-level root of the Xilinx part of your design is called xilinx, then this is the file that must contain the ibuf, ipad, obuf and opad cells that connect your design to the pins of the Xilinx package. You must include these connections, and the LOC attributes that say which Xilinx pin you are using before you run the Xilinx software. Also, you must have a xilinx.vsm file in your design directory before starting the next step.

Once you have the design completed, you can map the design to the Xilinx chip by running the xxx script from the /home/cs/handin/cs361/bin directory. Before running this software, connect to your cs361-pv/lab8 directory. Assuming that you have the cs361/bin directory on your path, the syntax is:

xxx <xilinx-design-name>

That is, even if your total design that includes xilinx and non-xilinx parts is called topa, the name that goes in the <xilinx-design-name> part of the xxx command is only the part of your circuit that is the Xilinx part. That is, inside your topa schematic there is an instance of a cell called xilinx which contains all the Xilinx parts. In that case you would run xxx xilinx to convert all the xilinx stuff into internal Xilinx format.

The result of running the xxx script is a whole bunch of extra files cluttering up your lab8 directory. These are all files created by the Xilinx software that have something to do with the conversion process. Some you will need to look at, most you can ignore. The script runs a variety of programs, but the part that will take the longest is a program called apr which stands for Automatic Place and Route. This is the program that is actually mapping your design onto the Xilinx chip. For large designs it is not uncommon for this program to take 30min or more to run. For your Triscuit it should be faster, but on a loaded machine it may take some time. Don't panic if it seems to be taking forever.

When the process is complete you should have (assuming there were no errors) a <design-name>.mcs file in your directory. This is a PROM file that contains all the Xilinx data to configure the chip to be your circuit. Note that I mentioned ``assuming there were no mistakes'' in the previous sentence. The script will report that it is done even if there were mistakes along the way that caused it to fail. You need to read the output of the xxx command carefully, as well as look at the log files mentioned in the output, before you believe that you actually finished successfully!

If you did get a new <design-name>.mcs file, then you're ready to burn the program into the EPROM that you were given when you checked out your Xilinx board. To do this, follow the directions on the paper stuck to the wall above the EPROM programmer. It's a simple matter of erasing the EPROM with the eraser-unit, sticking the EPROM into the burner, and following the instructions. The result is a program in the EPROM.

Once you have a programmed EPROM, and, by the way, you have wired up whatever needs to be wired up on your Xilinx board (the clock, the reset switches, the connector to the terminal, the lights, etc), then you're ready to roll. Put the EPROM chip into the socket on the Xilinx board. When you plug the board into your kit and turn the power on, the Xilinx chip automatically grabs the programming information from the EPROM and it's ready to go. Hit the reset button, and start Triscuiting!

next up previous
Next: Timing Simulation Up: No Title Previous: Procedure

Erik Brunvand
Sat Nov 29 15:21:21 MST 1997