Each of the microinstructions are, in turn, made up of fields that directly control the functional units of the 8-bit processor core. Microprogramming thereby allows you to have complete deterministic control over the technology, letting you tailor it to a specific application.
Microprogrammable functionality also eliminates the need for deep pipelines, out-of-order or speculative executions, cache hierarchies, or complex states. This keeps hardware to a bare minimum as well as ensuring no wasted computations to maximize efficiency.
At the same time, microprogramming offers total flexibility, since you can implement any computation with high efficiency. So while each OOHA is designed to be application-specific, they are based around what is effectively multi-purpose technology. And because the microinstructions are programmed directly into memory, you can reconfigure them at any time – on demand.