[REF] How to checkpoint FPGA state?


I am only familiar with our ISE Impact JTAG cable, and the software we provide.

Thru the Impact software, one can program the device, read the system monitor to determine the temperature, and the voltages, and perform a verify.
The verify step places the readback contents of the device into a file called impact.bin if the proper environment variables are set by the user (in Windows XP, these are


Parsing the readback file can be a bit arduous, as it is in binary format (I use a binary file editor that expresses the file in hex and binary), and we do not supply a map.  However, the .msk file (mask file) supplies information about where capture, and restore bits, and other dynamic content is located (so it may be ignored, as it changes).  Along with the ‘diff’ command (comapre two files, and express the differences, it isn’t too hard to find initial conditions (by changing them in your design), and other bit locations of interest.

Sorry I can not be of more help,

Austin Lesea
Principal Engineer
Xilinx San Jose

Workaround for fake FTDI chip on Windows

Recently, I bought some FTDI breakout boards as USB to serial converter. At first, everything works, but later after a driver update, nothing works any more. After a little bit search, it turns out the chips are actually fake chips (f..k)!

FTDI-FT232RLr real vs fake supereal

I don’t want to throw away the chips just as that (meanwhile, I’ve placed another order from another seller, let’s cross fingers), so I did a little bit search and then come across this post:

Update for a fake cable
However, the procedure is much simpler:
1. Download the driver from FTDI official website
2. Change the PID in the two INF files to the one you see in the Hardware Properties of the fake chip when connected to the PC
3. Turn off the “Driver Signature Validation” on Windows, restart, install the driver from device manager. And then it’s working as before.

(Sorry, FTDI, I didn’t expect they also make fake copies of the chip which is already at a low price.)