fastest and most reliable microcontroller produced?

[mamech]

hello

I made a search on site of microchip and atmel to make a comparison to determine which has a faster 32bit microcontroller, and I found that the highest family on microchip is this PIC32MZ (http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1005) which can operate at 200 Mhz maximum.

while in atmel has SAMA5D3 arm based which can operate up to 536 MHz at maximum (http://www.atmel.com/v2pfresults.as...0,1,2)),(i:8278,v:!(0,1,2))),view:list),sc:1))


As it seems , atmel fastest microcontroller is more than double speed as microchip fastest microcontroller, but I know that there are some details that only known by experts, that can make a lower speed microcontroller to have better performance than a faster one.

my question now, if I am about to use one of them for multiaxes servo control of industrial CNC machines, which will be more favorable??

thanks

 

[betwixt]

Strange that none of the Atmel data sheets are available. It is only available with 324 pins which suggests a BGA package, can you handle that?

As for reliability, I would take it for granted they are equally reliable, similar testing would be done on each family of devices and even over a production run, any problems would be fixed with a new silicon revision.

I wonder why you need such high speed for servo control, CNC is generally quite slow compared to the processing speeds of MCUs.

Although I can't be specific without the Atmel data sheet, the things to watch out for are:

1. The 'throughput' of a processor is related to the instruction execution speed, not the clock speed. A fast clock that needs many cycles to process each instruction may be slower than one with a low speed clock that performs one instruction per cycle.

2. How much additional interfacing is needed. For CNC work for example, you might have use of on-board quadrature decoders, some processors have them, some don't,

3. Is the supply voltage and hence output pin voltages able to drive peripherals without additional external level shifters.

4. What other peripherals does it need to communicate with other devices? (serial, USB, Ethernet, SPI...)

5. As mentioned earlier, can you or your board assembler handle BGA devices or are you better staying with pinned/legged devices.

Brian.

 

[mamech]

1. The 'throughput' of a processor is related to the instruction execution speed, not the clock speed. A fast clock that needs many cycles to process each instruction may be slower than one with a low speed clock that performs one instruction per cycle.

All of these points are really important and need to be determined, but the above mentioned point is the most important that I want to ask about . I think then that throughput measure of the processor can be how many MIPs that it can handle?

 

[tilz0R]

You must know, that Atmel's SAMA5 is Cortex A5 and is not microcontroller, but microprocessor. You will need something here so it will be able to handle everything.

 

[erikl]

Strange that none of the Atmel data sheets are available.

Sure it's available: SAMA5D3 Series data "sheet": 8MB with 1880 pages.

 

[betwixt]

Thanks Erikl. The original link to the product selector has links to the data sheets but they all go to '404' pages. I have the document from the link you posted and agree with TilzOR that it is a mocroprocessor rather than a microcontroller. That dramatically puts the cost up compared to a system built around the PIC32 MCU which has peripherals and program memory on board.

As for performance, each has their strong points, SAMA5D3 is undoubtedly faster as a core processor in a bigger system but the PIC32 is faster in a dedicated control application. Speed wise, the SAMA5D3 has a maximum bus speed of 166MHz while the PIC32 has a maximum of 100MHz on most pins, both much faster than you should need in a CNC application.

Brian.

 

[milan.rajik]

Why not a STM32 MCU ?

 

[betwixt]

It may be a good choice but the decision should be made with consideration of the final application. All three (and probably more) devices are suitable but each with their own plus and minus points, without knowing more about the demands the CNC machine places on them it isn't worth guessing which is best.

Brian.

 

[tilz0R]

I'm here also for suggest you STM32.

STM32F401 is 84MHz, powerful way too much for your CNC.
It can be done with F103 or less.

My 3D printer has Atmega2560 at 16MHz, no need more!