What are the correct methods for creating and debugging an SVF file?
To debug an SVF problem:
Use the iMPACT GUI
Assuming that you have access to the JTAG ports and a parallel cable, connect the chain to iMPACT and check the following items in order:
1. Have iMPACT identify the chain; this will indicate that the chain is properly set up.
2. Obtain the IDCODE for each device in the chain.
3. Attempt to program the device.
Use an XSVF file and a Parallel cable
If all of the functions above were executed without error in the iMPACT GUI, repeat the process with an XSVF file and the PLAYXSVF executable through the Parallel port:
1. Create an SVF file for obtaining the IDCODE, and convert it to an XSVF file.
2. Use "PLAYXSVF" with the file to ensure that the SVF file does not contain errors.
Any errors discovered will be reported. The TDI and TDO may also be investigated. The SVF file should be inspected to ensure that it was written correctly (this should not be an issue as long as the most recent service pack has been applied). If no problems with the SVF are reported, investigate the error further; for instance, the presence of all "1"s or "0"s on the TDO would indicate that the TDO pin might have been shorted.
If an IDCODE can be captured, create a file to program the chain.
Ensure that the device programs and functions correctly.
Download to the microprocessor
Assuming that the device can be programmed via the parallel port with the XSVF file, problems with the board, device, SVF file, and XSVF file have all been eliminated. You should now investigate the interface with the microcontroller more closely; for further information on this, please see the Xilinx Application Note "Xilinx In-System Programming Using an Embedded Microcontroller" (Xilinx XAPP058).