Check your crypto chip with a Saleae logic analyzer

I have already noted the tiny full-function logic analyzer from Saleae. You can imagine my delight when I found this app note written by our security chip group on how to use the Saleae logic analyzer to debug the serial interface with one of our CryptoAuthentication chips, the ATSHA204.

The ATSHA204A includes a 4.5Kb EEPROM divided into 16 slots. This array can be used for storage of keys, miscellaneous read/write, read-only, password or secret data, and consumption tracking. Access to the various sections of memory can be restricted in a variety of ways and then the configuration locked to prevent changes. Access to the chip is through a standard I²C interface at speeds up to 1Mb/sec.

The Saleae logic analyzer has no problem keeping up with these fast speeds. ATSHA204 device supports either a single-wire interface (SWI) or two-wire interface (TWI) depending on the part number.


When you drop the right dll into the Saleae program directory, you will get a menu callout for the Atmel SWI (single-wire-interface).

You use a dll to add the single-wire debug analysis to the Saleae, while the two-wire interface debugging can be handled by the I²C menu pick. So check out the Saleae logic analyser. My buddies tell me it is worth every penny compared to the cheapo stuff on Seeed Studio since the mechanical engineering is so much better on the Saleae, and the quality of the test leads and the capability of the software, which is a huge part of what a logic analyzer does for you these days. It’s one thing to see highs and lows on the screen, but it’s really nice when the logic analyzer tells you what characters are being sent on the wire or wires.


The Saleae logic analyzer comes with high-quality cables and clips.

So check out the Saleae logic analyzers and be sure to secure your systems with a hardware-based security chip. When it comes to securing our intelligent, connected world, there’s no need to fear… Atmel CryptoAuthentication devices are here!

1 thought on “Check your crypto chip with a Saleae logic analyzer

  1. Room101

    Great article, only problem, where is the DLL required for SWI? I’ve hunted high and low both on Atmel and Saleae’s websites and farther afield, nothing.



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