[Jelmer] got curious about the TI CC26XX wireless MCUs and did a little decapping.
TI sells four different models of their CC26XX wireless MCUs. Three support one of the following: RF4CE, Zigbee/6LoWPAN, and Bluetooth and a further model which supports all protocols. Each IC has the same baseline specification: 128Kb Flash, 20Kb RAM and 15 GPIOs. [Jelmer] was curious to know if the price difference was all in the software. And in order to verify this decided that decapping was the only thing to do!
We’ve covered decapping using Nitric acid before, as well as lower tech techniques. Luckily [Jelmer] had access to Nitric acid and a fume hood, not the easiest items to get hold of outside of a research lab (checkout the video of the IC bubbling away below). [Jelmer] got some great die shots under an optical microscope and was able to confirm that the die markings are identical. This opens the door to future hacks, which might allow the cheaper models to be re-flashed, expanding their capabilities.