how to extract the contents of a bit file

[brightblade]

send .bit file to fpga through com port

Hi
I need to find a way to extract the contents of a xilinx bit file. I need to isolate the data bits and the header, time stamp etc... the bit file can be a design that i wanted to write for example into a PROM or into a directly FPGA. Is there anyone who knows the structure of the bit files. thank you all...

 

[Big Boy]

fpga model extract from mcs file

If your only intent is to extract the bitfile raw data, for the purpose of programing to a PROM for example (or configuring the FPGA using a microprocessor), you can use iMPACT.

You have 2 major mode in iMPACT. One is FPGA programming (you scan the chain, transfer via JTAG to the FPGA or PROM). Another one is PROM generator.

With PROM generator, you can specify a target PROM (so you can split across several of those PROM), or custom PROM. Note here that PROM reffer to any type of programable memory devices (flash, EEPROM, even RAM). You take for input your bit file, and you output to one of several data format (MCS i.e. Intel HEX, binary, ...).

iMPACT come as part of the ISE tools.

Big Boy

 

[EDALIST]

how big are fpga bitfiles

just look at the datasheet]euser manual, different parts have different bit file format, so check for the part you are working on. it is usually quite simple procedure.

 

[brightblade]

thanks for the help. I know about the impact and i'm using it the problem is I want to send the bit values from pci. With impact you can program fpga and proms through usb or parallel port. but i want pci... Any ideas...thanks

 

[ilikebbs]

ISE can generate .bit and .bin file according to your setting.
The difference between .bit and .bin file is the header. You can try to campare them.

Even you do not need to know the content of configuration file, FPGA will know the start bit and the end bit according to XILINX algorithm.

 

[brightblade]

I see thanks ilikebbs but here comes the next difficulty. Suppose that i have the bit file and i can send by configuration data to the JTAG pins of my fpgas through pci port. How will I send a file through pci if i don't know the contents? Can a fpga know the contents and be programmed correctly? I thought the xilinx software does the job. Is it fpga? (in my problem i can't use the xilinx software while programming. Because i'm programming through pci port )
Regards...