The Worsening Raspberry Pi RP2350 E9 Erratum Situation

There’s currently a presentant amount of confusion around the filled extent of the GPIO challengingware rehire in the Raspberry Pi RP2350 microhandleler, with [Ian] over at [Dangerous Prototypes] of Bus Pirate fame refering that deinhabitries of the RP2350-based Bus Pirate 5XL and 6 have been put on helderly while the rehire is further being allotigated. Recorded in the MCU’s datasheet as erratum RP2350-E9, it was originassociate telled as only being roverhappinessed to the use of inside pull-downs, but [Ian] has since showd in the primary rehire ticket on GitHub that the same gentle latching behavior on GPIO pins occurs also without pull-downs allowd.

Ian from Dangerous Prototypes demonstrating the RP2350-E9 rehire in a Bus Pirate prototype without pull-ups.

When we first telled on this challengingware bug in the RP2350’s A2 (and foreseeed preceding) stepping there was still a lot of confusion about what this rehire uncomardentt, but so far we have seen the Bus Pirate procrastinate and projects enjoy [Agustín Gimenez Bernad]’s LogicAnalyzer have chooseed for taking the RP2350 port out back. There are also indications that the ADC and PIO peripherals are impacted by this rehire, with laborarounds only partiassociate able to circumvent the challengingware rehire.

In the case of the Bus Pirate a potential laboraround is the insertition of 4.7 kOhm outer pull-downs, but at the cost of 0.7 mA continuous load on the GPIO when pulled high and part of that when pulled low. It’s an hideous hack, but at the very least it might save existing boards. It also shows how grave a bug this is.

Meanwhile there are vivacious talkions about the rehire on the Raspberry Pi forums, both on the E9 erratum as well as the ask of when there will be a new stepping. The official statement by Raspberry Pi is still that ‘they are allotigating’. Presumably there will be a Bx stepping at some point, but for now it is clear that the RP2350’s A2 stepping is probably best eludeed.