Description

The RP2350 adds several new PIO instructions/options compared to the RP2040 - currently they're not supported by MicroPython's @rp2.asm_pio assembler, so it's difficult to use them under MicroPython.

https://datasheets.raspberrypi.com/rp2350/rp2350-datasheet.pdf

The PIO changes are listed in Section 11.1.1. ('Changes from RP2040') - note that the first change is:

DBG_CFGINFO.VERSION indicates the PIO version, to allow PIO feature detection at runtime.
This 4-bit field was reserved-0 on RP2040 (indicating version 0), and reads as 1 on RP2350.

Specifically I'm interested in the new variants of mov that allow random-access to the FIFO queue with indexed arguments:

• mov rxfifo[y], isr
• mov rxfifo[], isr
• mov osr, rxfifo[y]
• mov osr, rxfifo[]

where:

• y : The literal token "y", indicating the RX FIFO entry is indexed by the Y register.
• <index> : A value (see Section 11.3.2) specifying the RX FIFO entry to write (valid range 0-3).

It's not currently possible to express these with the Micropython mov() assembler function, so far as I'm aware.

Support for the rp2040 was originally added to MicroPython with:

• rp2: Add new port to Raspberry Pi's RP2040 microcontroller #6791

See also:

• RP2350 pioasm .fifo putget configuration description raspberrypi/pico-feedback#437

Code Size

Random-access to the FIFO queue is a pretty substantial upgrade for PIO! I really do not know how large/difficult the implementation would be though.

Implementation

I hope the MicroPython maintainers or community will implement this feature

Code of Conduct

Yes, I agree