Barrel shifters are one of those things that end up a lot bigger in FPGAs than ASICs. Not really because a barrel shifter is harder, but because FPGAs optimise for most other common building blocks and barrel shifters are kind of left behind.
But even on the real RP2040, PIO is not small.
Take a look at the annotated die shot [0]. The PIO blocks are notably bigger than the PROC blocks.
But even on the real RP2040, PIO is not small.
Take a look at the annotated die shot [0]. The PIO blocks are notably bigger than the PROC blocks.
[0] https://assets.raspberrypi.com/static/floorplan@2x-a25341f50...