Here's [1] an example of a CPU with the same functionality that the parent poster is interested in: the ISA being implemented in what amounts to microcode. [1]

Here's [1] an example of a CPU with the same functionality that the parent poster is interested in: the ISA being implemented in what amounts to microcode. [1] https://en.m.wikipedia.org/wiki/Transmeta_Crusoe https://en.m.wikipedia.org/wiki/Transmeta_Crusoe