Downloading bitstream file to CW305


I’m super new here. I already have a bitstream file ready to be loaded on the CW305 board.
I’m not familiar with python but I have installed latest chip whisper tools (5.64).

VIVADO 2020.2 is installed.

What’s the easiest and fastest way to download both volatile and non-volatile bit file? maybe a script or so.

Thank you in advance


When you connect to the CW305, you can specify a bitstream to load:

target =, cw.targets.CW305, bitstream="path/to/my/bitstream.bit")

Thanks for your reply.

How to connect?
Where do I run this script?

Thanks again

You can connect via the chipwhisperer Python API:

import chipwhisperer as cw
target =, ...)

You can find its documentation at:


Hello, thanks again.

I got this msg:

WARNING:ChipWhisperer NAEUSB:Your firmware is outdated - latest is 0.32. Suggested to update firmware, as you may experience errors

It seems Fw update is mandatory, where can I get the latest fw and how to download it.



That message is just a warning, so it’s not mandatory, just a suggestion. If you want to update,
simply follow the steps in that link:

target =
prog = cw.SAMFWLoader(target)


In fact, it didn’t download the bit file. I did not get a progress status nor a confirmation.
I will try to update fw and retry downloading FPGA image.

Thank you

Hi, as a first step I suggest you try to go through our CW305 AES demo:

This will help rule out issues with your setup.

Also read over this to learn about the various switches on the board and what they do:


Everything works now.