[imtringued]

SRAM is very area intensive. What you're asking for is very greedy. The RISC-V core they are using is absolutely tiny.

[myrmidon]

Thats also a good point. For the big Milk-V systems I mentioned they use external DRAM-- but cache might still be a die-space issue (I'd assume that it's always shared completely between ARM/RISC-V cores, and would need to be scaled up for true multicore operation).

But I'm still amazed that this is a thing, and you can apparently just throw a full core for a different architecture on a microcontroller at basically no cost :O