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The CW305 target is an FPGA target board for use with the ChipWhisperer capture hardware. This board lets you test side channel analysis techniques on an Artix-7 FPGA. With this setup, a different toolchain is required: we won't be building C firmware with a makefile. This tutorial walks through the various steps required to run an AES-128 example on the CW305 target.

If you're used to working with the ChipWhisperer Lite XMEGA or the UFO targets, the CW305 board will feel a bit different. Rather than sending data through a UART directly from the capture hardware, we'll now use two separate connections to the target board.

[[File:CW305_CWLite_SCA.jpg|800px]]

In the ChipWhisperer examples, the Artix-7 FPGA is programmed using Verilog. This section describes how to open and build one of these projects. It also describes the layout of the AES-128 example, which is a good starting point for making new FPGA projects.

Note if you just want to follow along with the rest of the tutorials, you can use the pre-built bitstream (<code>.bit</code> file). In which case simply skip ahead to any of the following tutorials.

The first thing we'll need is [https://www.xilinx.com/support/download.html Xilinx Vivado HLx], which is their FGPA design software. The fully featured versions of this software require a $3000+ license. However, the WEBPACK version is free, with the limitation that it can only be used with 4 families of devices (including the Artix-7). This is a huge download, so get it started while you read (possibly also you'll have time for lunch and a few drinks).

This is enough for us to start poking around in the code.

If you're planning on making your own projects for side channel analysis, it's helpful to understand how the sample project is set up. Here's a high-level description of the different pieces:

* <code>aes_core.v</code>: The AES core module is an implementation of AES from Google. This is taken from the [https://github.com/ProjectVault/orp/tree/master/hardware/mselSoC/src/systems/geophyte/rtl/verilog/crypto_aes/rtl/verilog ProjectVault repository].

This project is already fully built for us. However, if you want to make your own project, you'll need to know how to build it. There are three steps that Vivado takes to turn our Verilog into a fully functional piece of code:

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With our FPGA bitstream in hand, we're now ready to capture a power trace. We can set this up using the ChipWhisperer Capture software.