[hakfoo]

I'd expect it would expand the market for customized SoC/microcontroller parts.

We know there's already a lot of "built to purpose" RISC-V products ending up in embedded environments. When you have less obligations to a restrictive ISA grant, you can make something that fits your needs exactly.

So the business case is second-order:

* As has repeatedly been joked, fab companies who aren't locked to a captive/capricious owner (Intel) look appealing. It likely isn't about cutting-edge there, but the flexibility to handle diverse custom orders. Plenty of these products will be like "133MHz and a couple hundred thousand gates" that would be fine on 90nm or bigger.

* Firms that can move from "product" to "consultancy". There's a lot of brilliant work in existing ARM and RISC-V MCUs, but will existing firms be able to move away from "here's a matrix of features, order from the list" and into "Let us meet with your team, build a custom pick-and-mix and add a bespoke unit to meet your need for (smaller number than was historically common) product-specific MCUs?"

[bradstewart]

Is there something unique to RISC that makes it inexpensive to manufacture custom chips?

Otherwise, I'd imagine the cost of the mask set and validation to far, far outweigh any reduction in unit cost you might see from a custom chip. MCUs are already extremely cheap, especially if you're buying significant quantities.