Is cw305-04-7a100-0.50-x, cw308 and cw308t-s6lx9 still in stock? For side channel attack, which specification of shunt resistance should be selected? In addition, how does cw308t-s6lx9 compare with cw305 in attacking AES?
You can purchase our products from our online store (https://store.newae.com) or from Mouser; you can check availability on each. Currently the cw305-04-7a100-0.50-x is not available, but the same board with a smaller 100 mOhm shunt resistor is available from Mouser.
Selecting shunt resistance is explained here:
Unfortunately due to the nature of FPGAs there is no simple answer for what is the optimal shunt resistance; it will depend on the size and nature of your design. Having the smaller 100 mOhm shunt means you should be ok for any design (the possible issue is that if the current draw of your FPGA design is very high, the voltage drop across the shunt resistor may cause the FPGA supply voltage to be too low for reliable operation).
The S6LX9 is a much smaller and older FPGA; furthermore, the CW305 has many additional features. WIth the cw308t-s6lx9, all you get is the ChipWhisperer 20-pin interface to the FPGA and the ability to do power measurement, clock glitching, and voltage glitching. The CW305 adds a long list of additional features: https://rtfm.newae.com/Targets/CW305%20Artix%20FPGA.html