Comments on EEE Journal: Nvidia Tegra 2 for Dual Core Netbooks/Smarbooks in...

There is no special information here - its all on ...

2010-01-04T08:30:28.606-08:00

There is no special information here - its all on Qualcomm's web site, and ARMs. An architecture license enables a company to design their own micro-architecture (a soft macro, or a custom hardened implementation etc.), and maintain compatibility with ARMs architecture. [Note: If all micro-architectures obey a given architecture, they are all compatible.]

There is no logic re-used by Qualcomm from any ARM macrocells. The soft macros that ARM designs are licensed to companies that don't want to (or can't afford to) design their own processor. ARM designs it once, and sells it many times.

Qualcomm have a big team of designers, and obviously have their own reasons for designing their own processor (such as being able to own their whole IP chain). It's a very nice processor. Their reasons for "re-inventing the wheel", as it were, might be to target higher frequencies than an off-the-shelf ARM core, or to implement higher performance memory/data processing than the more generic ARM designs.

@alxlr8 Thank you for clarifying! Now you make m...

2009-12-22T10:34:59.953-08:00

@alxlr8

Thank you for clarifying!

Now you make me curious: "Qualcomm have designed everything inside Scorpion from scratch"
I read this information in a few blogs and I ask myself what's really meant.
I couldn't imagine that Qualcomm didn't reuse any logic module, on the other hand it looks like you got insider information that I don't have ;-)

I can't understand why to reinvent the wheel? AFAIK with an architecture license you get the soft macro and you can modify whatever you like in order to achieve better performance, lower power consuption or just to add new features.

@djsm@ That's OK. It is sometimes difficult t...

2009-12-22T03:32:47.613-08:00

@djsm@

That's OK. It is sometimes difficult to find reliable information about ARM products in the "blogosphere", since ARM has always been relatively unknown.

As you say, though, Cortex-A5 is indeed scalable from 1 to 4 CPUs, and is an "MPCore" product.

Scorpion does indeed have ARMv7 architectural features that are also found on Cortex-A8, but they are not taken directly from Cortex-A8. In obeying the same architecture, they will have similar capabilities (although not all parts of the architecture are compulsory). Qualcomm have designed everything inside Scorpion from scratch.

@alxlr8 thank you for the very useful comments! ...

2009-12-21T12:15:07.656-08:00

@alxlr8

thank you for the very useful comments!

About MPCore: Thank you, I didn't know that ARM didn't develop a Cortex A8 MPCore.
To be precise I'm pretty sure an MPCore version exists also for the Cortex A5, beside ARM11 and Cortex A9.

About Snapdragon: You're again right. Technically the Scorption CPU isn't a Cortex A8. On the other hand Qualcomm got an ARMv7 architecture licence and I read somewhere that they took much from the Cortex A8 design since when they got the license the Cortex A8 was the only ARMv7 available. Of course I may be wrong.

I'll post corrections as soon as I get a few minutes!

Another quick comment (sorry). Qualcomm's Sn...

2009-12-20T10:43:48.861-08:00

Another quick comment (sorry).

Qualcomm's Snapdragon chipset doesn't use any ARM Cortex products. Instead, it uses Qualcomm's Scorpion CPU, which is of their own design under their ARM Architecture License.

Hi. Just a quick comment. There is no MPCore vari...

2009-12-20T10:41:35.809-08:00

Hi.

Just a quick comment. There is no MPCore variant of the Cortex-A8. Cortex-A8 is a single core processor. The only other MPCore product is indeed the Cortex-A9 (aside from the older ARM11 MPCore).

Thank you Brian! Yes I definetly made a mistake: t...

2009-12-19T09:36:19.676-08:00

Thank you Brian!
Yes I definetly made a mistake: the Nvidia Tegra 1 uses an ARM11 core, not an ARM Cortex A8

Tegra 1 is not Cortex-A8, it is ARM11.

2009-12-18T08:11:24.847-08:00

Tegra 1 is not Cortex-A8, it is ARM11.