Machine Architecture vs. Microarchitecture?

[carlodelmundo]

Hi.

I'm trying to decipher the differences between the machine architecture and microarchitecture.

I believe Machine Architecture is:

• The ISA (such as x86)
• Von Neumann Model for Computing?

and I believe the Micro Architecture is:

• Specific implementation of some arbitrary ISA (such as the Pentium processor)

Is this reasoning correct? Could someone give me an example of a microarchitecture AND machine architecture?

 

[jsgruszynski]

That's pretty much it. They are pretty close and nearly interchangeable.

Other machine architectures are Harvard and Modified Harvard. But you'll also see Stack machines vs. Register machines labelled as machine architectures.

Microarchitecture can also refer to microcode (or nanocode) structure so that you have x86 as a "vertical microcode" microarchitecture but 68000 as "horizontal microcode".