Some remarks about the usage of Xilinx ISE 6

Xilinx ISE 6 is a powerful software suite with a (mostly) intuitive GUI, but some things are just not as obvious as they could be. I'll try to explain some details that seem to be important, but not really obvious.

Keywords (for search engines): Xilinx, VHDL, Verilog, ISE (Integrated Software Environment), ECS (Engineering Capture System)

• In the window "Processes for Source" you can see a treeview of the source that is selected in the window above, but normally only the highest level of the tree is visible, so often you can find some very important information only if expanding the treeview (by clicking on the appropriate "+" left to some icon). So be sure to expand the whole tree when searching for some specific information.
• One of the most powerful tools in this tree is the command "View RTL Schematic". It shows a diagram of the whole project ("Top Level Symbol)". If you doubleclick it, you can find the details. They are displayed like a interactive map, you can zoom in and out, and if one instance of anything contained in your project is found, you can doubleclick that, too.
• Also useful when viewing a schematic: Nearly everything has a sensible mouseover text, so be sure to rest the mouse over an item you try to understand. You can also highlight any item by singleclicking on it, and many by pressing (and keeping pressed) CTRL, while singleclicking them all. That way you can highlight (for example) a bunch of wires to see where they come from and where they go to. Just like doubleclicking "zooms" into detail view of the component, you can "zoom out" to the component that contains the one currently displayed. Use the "Pop"-Entry to zoom out.
• When reading the Synthesis Report, be sure to look for all the lines beginning with "Info:", "Warning:" or "Error:", because all of them can contain very useful info, especially the "Info"-lines may be more important that the name implies. Be sure to read them all.
• When doubleclicking on a schematic file, the "Xilinx ECS"-tool is launched (the same tool that is launched when viewing the RTL schematic), but this time you can also change things, not just view an autogenerated schematic. It's a good idea to use this tool to rename the instances of the components used in the schematic to some sensible name. Just doubleclick the instance, and change the field "InstName". This way, you can easily recognize them later (for example, when viewing the RTL schematic the next time). The autogenerated names are not very useful.
• You will often have a hierarchy of schematics, where each schematic can contain other schematics and also sourcecode files (VHDL or Verilog). If you have changed a sourcecode file and added/removed some inputs or outputs, you may have to change the wiring of the instances of this component inside a schematic higher up the hierarchy. But the symbol for the changed component does not update automatically, you have to initiate the update. Try the entry "Design Entry Utilities" -> "Create Schematic Symbol" while the sourcecode file is selected in the "Sources in Project" window.
• When using the help for Xilinx ISE 6, you should have a JVM (Java Virtual Machine) installed, otherwise the help will be much harder to use. Also be sure that you enable Java in your default webbrowser, otherwise the JVM won't be invoked.

Some remarks about the usage of Xess Gxsload

Gxsload is a small utility to upload/download to/from RAM, Flash-ROM and FPGA/CPLD of a prototyping board, but the usage is a bit "different". Here are some hints on how to get it doing what you want it to.

Keywords (for search engines): Xess, Gxsload, upload, download, bitstring, RAM, Flash-ROM, FPGA, CPLD

• The selection "Upload Format" of course is also valid when downloading.
• You can't select the filename when copying the contents of the RAM or Flash of the board to your local PC, but you can select the target directory. If you just click the yellow icon, the file ends up in the directory where the tool itself is located ("application dir."), if you drag'n'drop it to any windows explorer window, the directory displayed in the explorer window is used as the target dir., but there's one catch: You still have to be able to write to the dir. the tool resides in, because the file is created there and moved to the target dir. Sounds stupid, but that just seems to be the way it is. If you lack the rights, everything seems to be normal, but after quite some time, it suddenly fails.
• Every time you change the selection of the up/download format, a text file inside the application dir. is rewritten, so be sure to have the (NTFS-) rights to do so.