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Relationships between microarchitecture, ISA, etc

Posted: Tue Jun 26, 2012 5:06 am
by cxzuk
Hi all,

Id be very grateful for a good description of what the meaning and relationships are of;

(Term - Example - What i think it is)
* Instruction Set Architecture - x86 (IA-32?), (x86-64[1]) - Architecture related to programming, Details Registers, Instructions, etc (Specifies endian?)
* Instruction Set Architecture Extensions - MMX, SSE, (P6??[2]) - An additional architecture to programming, Does not alter the original ISA?
* Microarchitecture - AMD K10 - A Design that will support an ISA, in this example x86-64
* Microarchitecture revision? - AMD K10 stepping 3 - A revision on a design
* Microarchitecture implemenation? - AMD ATHLONII X4 645 - An implementation of a design? (Specifies page size's and other characteristics? but constrained by the ISA?)

And anything else i may have forgotten.

Thankyou,
Mike Brown

[1] x86-64 is another ISA, not an extension to x86?
[2] Wikipedia states that Intel P6 is an x86 extension, is this correct?

Re: Relationships between microarchitecture, ISA, etc

Posted: Tue Jun 26, 2012 6:35 am
by JamesM
Hi,
cxzuk wrote:Hi all,

Id be very grateful for a good description of what the meaning and relationships are of;

(Term - Example - What i think it is)
* Instruction Set Architecture - x86 (IA-32?), (x86-64[1]) - Architecture related to programming, Details Registers, Instructions, etc (Specifies endian?)
Correct.
* Instruction Set Architecture Extensions - MMX, SSE, (P6??[2]) - An additional architecture to programming, Does not alter the original ISA?
Yes. Usually augments the ISA without requiring forwards compatibility.
* Microarchitecture - AMD K10 - A Design that will support an ISA, in this example x86-64
The microarchitecture is the implementation of the ISA.
* Microarchitecture revision? - AMD K10 stepping 3 - A revision on a design
Yes, much like a release number in a software product.
* Microarchitecture implemenation? - AMD ATHLONII X4 645 - An implementation of a design? (Specifies page size's and other characteristics? but constrained by the ISA?)
Microarchitecture implementation and microarchitecture are synonymous as far as I know. I can't think of any difference between them.


And anything else i may have forgotten.

Thankyou,
Mike Brown
[1] x86-64 is another ISA, not an extension to x86?
It can be seen as either, depending on your perspective. It adds another operating mode, has a new ABI and new registers. So it is a new architecture. It's also backwards compatible though, so it could be considered an extension...
[2] Wikipedia states that Intel P6 is an x86 extension, is this correct?
No idea.

Cheers,

James

Re: Relationships between microarchitecture, ISA, etc

Posted: Tue Jun 26, 2012 8:54 am
by Combuster
cxzuk wrote:[2] Wikipedia states that Intel P6 is an x86 extension
Quote wanted.

P6 is a microarchitecture, which later evolved to become the name of the general out-of-order implementation strategy employed from the Pentium Pro to the Core series (Excluding the Pentium 4s and Atoms). It implements the x86 ISA with a number of extensions.

Re: Relationships between microarchitecture, ISA, etc

Posted: Tue Jun 26, 2012 11:08 am
by cxzuk
Thankyou guys,

that was a great help.
* Microarchitecture implemenation? - AMD ATHLONII X4 645 - An implementation of a design? (Specifies page size's and other characteristics? but constrained by the ISA?)
Microarchitecture implementation and microarchitecture are synonymous as far as I know. I can't think of any difference between them.
Im guessing it would be a refinement of the details? - But what details im not sure of. Will look into this more.
Combuster wrote:
cxzuk wrote:[2] Wikipedia states that Intel P6 is an x86 extension
Quote wanted.
https://en.wikipedia.org/wiki/X86 wrote: x86-64: added 1 GB pages.
Extensions x87, IA-32, P6, MMX, SSE, SSE2, x86-64, SSE3, SSSE3, SSE4, SSE5, AVX
Open Partly. For some advanced
It cant be an extension from my understanding?

Thankyou,
cxzuk

Re: Relationships between microarchitecture, ISA, etc

Posted: Wed Jun 27, 2012 7:24 am
by JAAman
i don't know how you could call P6 an extension -- it was (as was earlier stated) the micro-architecture used for the PentiumPro and PentiumII/III

however, the P6 did add a few extensions:
PAE and PSE-36 were both added with the P6, so perhaps that is what it is referring to?