This Video Tour Dives Deep Into the Raspberry Pi RP2350's Silicon Die — By Stripping Off Its Package

Pseudonymous YouTuber "electronupdate" has peered deeper than most into the inner workings of Raspberry Pi's new RP2350 microcontroller — by peeling off its lid and capturing images of the silicon the lies beneath.

"Star of the show is the new RP2350," electronupdate writes of their analysis. "A number of changes [over the RP2040], perhaps the most intriguing is two Arm [Cortex-]M33 cores or two RISC-V Hazard3 cores. No question that Arm dominates the embedded processor space, however there is a challenger on the sidelines: RISC-V. Rather than taking the risk of building a RISC-V [product] they cleverly put both on their next die allowing the customer to switch between architectures if they want. This is a clever way of judging market demand without exposing too much cost."

While Raspberry Pi has shared much about the Raspberry Pi Pico 2 and the dual-architecture RP2350 microcontroller that powers it since the launch earlier this month, the company hasn't gone deep into analyzing exactly what's inside that square black chip package — with electronupdate taking on the challenge and de-encapsulating a chip, sadly packaged in a way to make non-destructive die imaging impossible, to analyze what's going on within.

"Same 40nm [process] as the previous [Raspberry] Pi Pico [RP2040]," electronupdate notes in their analysis, which was brought to our attention by Adafruit, "but the die is quite a bit larger. [It's a] classic bit of design! The power supply is a buck-boost from Richtek, Interesting choice as it allows the assembly to be powered from a voltage as low as 1.8V (battery use, perhaps?)"

Other highlights from the analysis, which was made more challenging by the interesting parts being covered by a power distribution network that needed careful removal, include spotting blocks reused from the original RP2040 ("the [RP2350] very much is an incremental design," electronupdate surmises), an on-die voltage regulator ("I'm not quite sure why they put a voltage regulator on there," the YouTuber notes), the four analog to digital converters (ADCs), and the on-chip memory.

This latter was put under close observation, for one very good reason: the chance at a cash prize. "[Raspberry Pi has] a contest going where if you can read a secret out of the ROM, I think, they have a little prize going," electronupdate says, referring to a contest launched at DEF CON 32 earlier this month. "A physical attack is actually a fairly successful approach, however we have to do selective metal delayering which is actually somewhat sophisticated, but I suspect you could take the secret out that way."

The full tour of the chip is detailed in the video embedded above and on electronupdate's YouTube channel. More information is available in a companion blog post.