AICA details

So far I've heard that it's a 32-bit RISC ARM7 variant, running at or around 22.5MHz (software defined). It apparently has a 64-channel wavetable and an 128-step DSP. I don't understand what the later stepping refers to.

There are some highly technical documents I've found which detail register addresses and behaviours, which is too technical for me.

Can someone give me a more general run-down on the capabilities of the AICA chip? What is it capable of (reverb, ADSR, pitch/time shift?) and how flexible is it? What audio capabilities does it have in hardware and what needs to be implemented in software?

well, what the AICA is is the sound chip with an embedded arm. Basically all i've ever seen done with it is to play out raw buffers (8 bit, 16 bit, stereo/mono, adpcm) or playing sound effects. If you're using kos, there is a default piece of software loaded onto the arm to run. If you wanted to use any advanced functions you'd either have to write your own program for it, or write directly to the registers and whatnot.