Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU - Page 2

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Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
2013-11-20 06:34, Bill Giovino skrev:
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And you are sure that this is faster than the Atmel AT91SAM9XE
ARM926 based flash microcontroller which been around for 3-4 years?
Running at 180 MHz but different architecture/flash and it
can execute out of external SDRAM, which the PIC32MZ
cannot do, according to the block diagram.

It is not clear what kind of bandwidth you will get from the flash,
but most flash memories will not run more than 20 MHz
so running out of DRAM is typically faster.

You can of course argue that it is cheating, but
if the definition is that you have internal SRAM and Flash,
then the SAM9XE fits.

In a real application, you are going to have problems if peripherals
have to be handled in interrupes, and not with DMA,
and the PIC32MZ only has 8 channels, which is not a lot.

BR
Ulf Samuelsson


Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU

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If i read it correctly, PIC32MZ requires 2 wait states at 200MHz.  So, program flash is probably running at around 70 to 80MHz.  BTW, flash instruction path is 128 bits with 16K cache.

Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
2013-11-21 01:55, snipped-for-privacy@gmail.com skrev:
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 > BTW, flash instruction path is 128 bits with 16K cache.
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I dont know how you come to that conclusion
200 / (1+2) = 66 MHz.

And as someone else pointed out, the Renesas parts can run the flash at  
100 MHz.

BR
Ulf


Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
On Saturday, November 23, 2013 2:38:22 PM UTC-8, Ulf Samuelsson wrote:
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Good catch on my bad math.  Should have said 60 to 70 MHz.

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Or you can run it on sram at 200MHz+.  

On a 80MHz MX, i have done OC 120MHz.

On a 200MHz MZ, perhaps we can try 300MHz.

Be sure to be able to stop SRAM OC with boot option.  Otherwise, you might not be able to reprogram the chip.

Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
On Thursday, November 21, 2013 1:25:06 AM UTC+2, Ulf Samuelsson wrote:
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Actually more. Things like the Ethernet have dedicated DMA which is not part of the general DMA pool.

Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
On 21/11/13 16:00, Rocky wrote:
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From the picture it looks like there are dedicated DMA's for the
Ethernet, CAN, USB, SQI and crypto engine - which is nice.

One thing that can make a big difference to usability is whether the
data cache is synchronised with these DMA channels (i.e., does the cache
snoop their transfers?).  I've worked with processors where the
dedicated Ethernet DMA was not snooped - you have to make sure your
Ethernet buffers are mapped to non-cached memory areas (assuming the
processor has an MMC or MMU supporting that), or you have to add extra
cache flush and invalidate code for any accesses.

But given the state of the errata for this chip, it is a toss-up whether
such snooping works or not.

It's a shame that Microchip have released this device in its current
state.  The MIPS microAptiv core is a great cpu, and it would be good
for the market for ARM to get some real competition.  But with these
half-tested devices from Microchip being the best-known general
microAptiv microcontrollers, there is a real danger that people will
assume the /core/ is bad rather than just incompetence of Microchip's
test engineers combined with over-enthusiastic PHB's and sales folk.
With the current errata - full of modules that simply don't work and
have no fixes or workarounds - this chip should never have been released
for the general public.


Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
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So the question becomes _why_ have they released it now ?

It was pointed out in another message that evaluation boards have been
released which depend on these non-working features.

That means after a few months have elapsed and these problems have been
(hopefully) fixed, some people are still going to start with a negative
impression of the PIC32MZ instead of starting with a neutral impression
of the PIC32MZ based on it's capabilities at that time.

IOW, I don't see how releasing it now instead of taking the hit caused
by another delay could have ever been considered to be a good idea.

Simon.

--  
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world

Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU

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Maybe a competitor is about to release something...

Wish is had floating point like stm32f4.

--  
/*   snipped-for-privacy@world.std.com AB1GO */                        /* Joseph H. Allen */
int a[1817];main(z,p,q,r){for(p80%;q+p-80;p-=2*a[p])for(z=9;z--;)q=3&(r=time(0)
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Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU
snipped-for-privacy@TheWorld.com (Joseph H Allen) writes:

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Like ADI CM4xx? 240MHz M4.

<http://www.analog.com/en/processors-dsp/cm4xx/products/index.html>


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--  

John Devereux

Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU

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MIPS/ImgTec only announced their first microcontroller core with FP  
support a few months ago (and I'd really rather not Microchip tried to  
roll their own. If they did the errata sheet would probably mention  
something about badgers mauling your face.)

-a

Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU

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FP aside, i am more interested in the 12 bits A2D and 512K sram. Hopefully, they won't mess up these too badly.  At least they have 64 pins package.  Most M4 start with 100 pins.


Re: Microchip PIC32MZ Flash Microcontroller is the World's Fastest 32-bit MCU

 >It is not clear what kind of bandwidth you will get from the flash,
 >but most flash memories will not run more than 20 MHz

Buy Renesas, they can do 100Mhz with 0Wait and if it is not fast
enought, use a SH7264 with 1MByte internal Ram.
Ups...there is now a new SH7268 with 2624KByte internal Ram!

 >In a real application, you are going to have problems if peripherals
 >have to be handled in interrupes, and not with DMA,
 >and the PIC32MZ only has 8 channels, which is not a lot.

The SH2A had 16 Register bank to switch very fast for every IRQ. :-p

Oh..and 64kByte Dualport Ram is cute, too....  

Olaf


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