I have a design which stores data in the XS Board RAM. How can I get the updated RAM contents back into the PC?
Version 3.0 of the XSLOAD program lets you upload the contents of the XS Board RAM to the PC through the parallel port. The RAM data is stored as a HEX file.
The following DOS command shows an example which uploads the contents of the XS95 Board RAM between addresses 0 and 128 to a file called DUMP.HEX:
C:> XSLOAD -UPLOAD 0 128 DUMP.HEX
This command does not disturb the circuit which was programmed into the XS95 CPLD before the upload operation.
The same upload command for an XS40 Board is:
C:> XSLOAD FILE.BIT -UPLOAD 0 128 DUMP.HEX
Notice that you must supply a bitstream file to upload the RAM from an XS40 Board. You can use any bitstream file as long as it is one that can be downloaded into the particular FPGA on your XS40 Board. XSLOAD does not load this bitstream into the XS40 Board, but it does look into the bitstream file to determine the type of FPGA installed on your XS40 Board. XSLOAD uses this information to load an appropriate RAM interface circuit into the FPGA so the data can be passed through the parallel port. This will erase whatever circuit you programmed into the FPGA before the upload occurred, so you will have to reload your circuit after the upload is completed.