HP Prime use ARM 9?

[sasa]

Official datasheet for HP Prime is not specific about used ARM chip. Some sources (probably after teardown) indicate that is Samsung S3C2416XH-40.

If that can be confirmed, this ARM 9 based chip is quite old and probably obsolete until now. I have impression ( I'm not a professional EE), that ARM base gives the fastest grown family which offer extreme powerfull chips with quite affordable prices.

I'm also aware that new design and production based on more powerful and modern ARM chip is quite costly, however that eventually will have to happens.

What would be the most logical candidate from a professional EE point of view to be used in theoretically redesigned HP Prime?

Different Cortex series seem to be quite popular nowadays... In any event, it seems to me that overproduction of many series and models is another significant variable into equation to decide for one specific model...

[Claudio L.]

(07-18-2018 10:25 PM)sasa Wrote:  Official datasheet for HP Prime is not specific about used ARM chip. Some sources (probably after teardown) indicate that is Samsung S3C2416XH-40.

If that can be confirmed...

I confirm it. I opened one.

(07-18-2018 10:25 PM)sasa Wrote:  What would be the most logical candidate from a professional EE point of view to be used in theoretically redesigned HP Prime?

Logical? I don't know, but a cool illogical one could be something based off of the Parallela board. The HP Prime is a good calculator, so why not give it 32 gigaflops?
But it might be too power hungry for a handheld, I don't know.

[mfleming]

(07-19-2018 02:05 AM)Claudio L. Wrote:  Logical? I don't know, but a cool illogical one could be something based off of the Parallela board. The HP Prime is a good calculator, so why not give it 32 gigaflops?
But it might be too power hungry for a handheld, I don't know.

The Adapteva board with a 16 core Epiphany chip required a 5V 2.5A wall wart supply, but that was mostly the fault of the Xilinx Zynq chip. A multi-core ARM chip like that used in cell phones or tablets would be a better choice, but to what purpose? Admittedly, a multi-threaded HPPPL would be a sight to see!

As a side note, Andreas Olofsson, single handedly responsible for the design and tape-out of the 16-, 64- and 1024-core Epiphany chips has moved on to DARPA. Adapteva remains a viable company producing products available from Digi-Key.

~Mark

[cyrille de brébisson]

Hello,

Prime does indeed use an older ARM9 based design.
ARM9 have been the workhorse of the ARM familly until the exponential growth of smartphones caused them to create the newer Cortex series...

The Cortex M series are kind of the successor to the ARM7 series. A Cortex M4 is now used in the 12C and replaces an older ARM7TDMI...

The Cortex A series replaces the ARM9 series (A stand for 'application'). The main difference from a feature point of view is that the A series have a MMU while the M series do not.

A series chip commes in all flavours and speed and have had their own generations...

The main differences are speed grades, 32 or 64 bit and, number of parallel ALU and pipeline depth.

Add parallel ALU and pipeline depth and you can run faster and do more at the same time. But the cost is increased complexity and power use.
Decrease them and the CPU is simpler, consumes less, but can not perform as fast frequency wise and can not do as many things at the same time...

Then you have core count, cache and periferials in the chip...
More core = more stuff you can do in parallel. However prime is realy much more of a single thread system, so there is no gain in paralelism there.
More cache = higher speed as there is less RAM access needed. It also decrease power use because RAM consume power to access.
Periferials can include things like GPU which are usefull for mobile phone (because that it all we need; 3D on a phone!!!!) but also much more important stuff like IO pin managers and LCD drivers...

Should one design a calcualtor at the moment, a Cortex A7 would be a good choice. low power, but still significantly better than the ARM9. Cheap and plentifull enough. You can find such CPU in low end phones/tablets... and apparently in high end graphical calculators...

Cyrille

[John Keith]

GPUs can be useful- many PC applications such as Mathematica and Photoshop use the GPUs on the PC's graphics card to accelerate floating-point calculation. The Prime's OS would, of course, have to be re-written to take advantage of the GPU and mutithreading but boy would it be fast!

[cyrille de brébisson]

Hello,

Yes, GPU (at least some of them, Compute GPU) can be used this way.

However, it is more than just rewriting the OS, it is a rewrite of each grapher function that would need to happen.

Basically, Each time you enter a math expression (let us say in the 3D grapher), the system would need to transform this expression in a GPU program (compile it if you want), dispatch it for execution there (assuming that it is not too complicated), gather the returns and draw them.

HOWEVER, since the GPU is 32 or 64 binary floats only, the results will not always match the command line calculation (which is BCD). Complex functions like finance stuff or stat stuff, would need to be recreated for the GPU. You would not be able to draw/graph your user programs anymore (as they would not be translatable to GPU programs...)
Of course the GPU could be super usefull when doing large matrix operations such as a numerical matrix inversion or something like that.

Simillary, multi threading would be hard because, assuming once again that you use non "basic" equations, the whole interpreter would need to make sure that there is no inter thread issues...
For example, concider the drawing of the valid expression: sin(A:=X)
Multi thread it and you see that 2 threads might want to store in A at the same time... This is a big problem!

So, yes, it can be done. And for some apps like Photoshop, it is actually easy to implement.
For other apps, it is hard :-(


Cyrille