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700 points elipsitz | 3 comments | | HN request time: 0.602s | source
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ryukoposting ◴[] No.41195070[source]
I can't imagine someone using an RP2040 in a real product, but the RP2350 fixes enough of my complaints that I'd be really excited to give it a shot.

There's a lot going for the 2040, don't get me wrong. TBMAN is a really cool concept. It overclocks like crazy. PIO is truly innovative, and it's super valuable for boatloads of companies looking to replace their 8051s/whatever with a daughterboard-adapted ARM core.

But, for every cool thing about the RP2040, there was a bad thing. DSP-level clock speeds but no FPU, and no hardware integer division. A USB DFU function embedded in boot ROM is flatly undesirable in an MCU with no memory protection. PIO support is extremely limited in third-party SDKs like Zephyr, which puts a low ceiling on its usefulness in large-scale projects.

The RP2350 fixes nearly all of my complaints, and that's really exciting.

PIO is a really cool concept, but relying on it to implement garden-variety peripherals like CAN or SDMMC immediately puts RP2350 at a disadvantage. The flexibility is very cool, but if I need to get a product up and running, the last thing I want to do is fiddle around with a special-purpose assembly language. My hope is that they'll eventually provide a library of ready-made "soft peripherals" for common things like SD/MMC, MII, Bluetooth HCI, etc. That would make integration into Zephyr (and friends) easier, and it would massively expand the potential use cases for the chip.

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alex-robbins ◴[] No.41197884[source]
> A USB DFU function embedded in boot ROM is flatly undesirable in an MCU with no memory protection.

Are you saying DFU is not useful without an MMU/MPU? Why would that be?

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1. ryukoposting ◴[] No.41198402[source]
It's certainly useful, but having it embedded within the hardware with no way to properly secure it makes the RP2040 a non-starter for any product I've ever written firmware for.
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2. TickleSteve ◴[] No.41199475[source]
it has secure boot and TrustZone.
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3. crest ◴[] No.41200023[source]
Not the RP2040. That chip has no boot security from anyone with physical access to the QSPI or SWD pins.