Pico 2 / RP2350 - are PIO2 State Machines (8,9,10,11) supported?

[IntergalacticMicrosystems]

Just checking to see if this is a known issue before digging in further.
I did search, but may have missed something.

Here's what I'm seeing:
Plain Raspberry Pi Pico 2 board
I've tried both the MP 1.25.0 release UF2 and a compiled UF2 from micropython-master as of 2025-6-14.

pio_1hz.py example - works when specifying 0 - 7 ids, fails with 8 - 11.

Removing the irq doesn't change the behavior.

Appears to be setting the PIO registers differently for 8 than it does for 0 or 4 (for example)

Thanks

[GitHubsSilverBullet]

Affirm!
Even the Pin class misses some things:
['__class__', '__name__', 'value', 'ALT', 'ALT_GPCK', 'ALT_I2C', 'ALT_PIO0', 'ALT_PIO1', 'ALT_PWM', 'ALT_SIO', 'ALT_SPI', 'ALT_UART', 'ALT_USB', 'IN', 'IRQ_FALLING', 'IRQ_RISING', 'OPEN_DRAIN', 'OUT', 'PULL_DOWN', 'PULL_UP', '__bases__', '__dict__', 'board', 'cpu', 'high', 'init', 'irq', 'low', 'off', 'on', 'toggle']
Note that there's no 'ALT_PIO2' and manually setting Pin.alt_mode to 8 (for PIO2) does not work either.
Manually forcing mem32[IO_BANK0_BASE+GPIO25_CTRL] = 8 mem32[PADS_BANK0_BASE+pads_GPIO25] = 1<<4 won't help either.

[IntergalacticMicrosystems]

Thanks, I'll do a bit more digging

[IntergalacticMicrosystems]

From the user side - these are set correctly (comparing to how it sets them for PIO0):

PADS_BANK0_BASE + PADS_GPIO25
IO_BANK0_BASE + GPIO25_CRTL
IO_BANK0_BASE + GPIO25_STATUS

Looking at the PIO registers - all look OK / expected except SM0_EXECCTRL
In this example, I've setup 3 SMs with blink_1hz() code (no IRQ), just the id and pin set differently.
IDs = 0,4,8

Pre create SMs

31   27   23   19     15   11   7    3
0000_0000_0000_0001___1111_0000_0000_0000  PIO0_BASE + SM0_EXECCTRL (502000CC)
0000_0000_0000_0001___1111_0000_0000_0000  PIO1_BASE + SM0_EXECCTRL (503000CC)
0000_0000_0000_0001___1111_0000_0000_0000  PIO2_BASE + SM0_EXECCTRL (504000CC)

Post create SMs

31   27   23   19     15   11   7    3
0000_0000_0000_0001___1111_1011_1000_0000  PIO0_BASE + SM0_EXECCTRL (502000CC)
0000_0000_0000_0001___1111_1011_1000_0000  PIO1_BASE + SM0_EXECCTRL (503000CC)
0000_1000_0100_0000___1000_0000_0000_0000  PIO2_BASE + SM0_EXECCTRL (504000CC)

Writing the correct value to PIO2_BASE + SM0_EXECCTRL doesn't make it run, so it looks like something else is also wrong.

[IntergalacticMicrosystems]

I've started an issue for this with what I've found so far.
#17509

[peterhinch]

See also #17047 - RP2350 PIO code is fragile, apparently a result of a change to the hardware design of GPIO pins.

[GitHubsSilverBullet]

As a sidenote, manually (viper) setting up the StateMachines in PIO2 works flawless.