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Topic: 32 bit Microcontoler (Read 6832 times) previous topic - next topic

Senso

I can go to the Maple store and buy it, I can download its IDE and compile code, so, how can I not use it?
In fact actually in working with 80Mhz PIC32's, so its a wee little faster than all those 72Mhz ARMs lol

Alvaro

You're right, that was meant for @westfw. :)

Alvie

westfw

Quote
You're right, that was meant for @westfw.

So the FPGA implementation of the ZPU is essentially a 32bit CPU that interprets an 8bit instruction stream?  Interesting.  At 4 or more clocks per instruction, it's going to have a difficult time competing with even an AVR, except when the 32bit-ness improves things a great deal...

The problem I usually have with FPGA based CPUs is that their power-consumption really sucks compared to a dedicated microcontroller.  The spartan 3e series needed here runs 75+ mA quiescent ?!  (I couldn't figure out from the datasheet how much it would dissipate in "typical" operation; I guess that's too complicated for an FPGA.  ("use XPower Estimator or XPower Analyzer that is part of the development environment.")

Alvaro

Well, ZPUino Premium Core (which is published right now) uses mostly 2-clock cycles per instruction, and ZPUino Extreme will do mostly 1 cycle/instruction.

See this post http://zpuino.blogspot.com/2011/04/zpu-core-comparison.html for a core overview.

Also don't forget it is able to run at significant higher speeds even in low-end FPGA (right now 96MHz).

And yes, power consumption varies a lot, and you have to take special care about it. Gated clocks are a solution (ie, disable parts of the design when you don't use them). I'm not paying yet attention to that, but power optimizations are in my to-do list.

Also you have the power to put dedicated hardware inside the FPGA, thus saving on external components (and in some scenarios even power).

Álvaro

westfw

Can you get arduino-like PWM or serial on "any" pin (up to ~20 pins, anyway) by dynamically changing the definition of the logic on each pin?  That would be neat.  I've been looking at Cypress's PSoC chips with similar ideas...   ANY arduino-specific hardware customization would be ... interesting.  (PWM output is a good example.  Implementing 20 pins worth of arduino-style analogWrite functionality ought to be MUCH easier than implementing 20 pins worth of general purpose timer/counter module.  (to start with, you'd only need one counter!)

Alvaro

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Can you get arduino-like PWM or serial on "any" pin (up to ~20 pins, anyway) by dynamically changing the definition of the logic on each pin?


Yes. Most IO devices (timers, SPI, ADCSPI) can be bound to any pin. This is very similar to microchip PPS.

Álvaro

westfw

I meant 20 PWM pins simultaneously.  Also moving a limited number to your choice of pins is also an interesting idea.

Alvaro

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I meant 20 PWM pins simultaneously

Yes, a single device output can map to more than one pin. Basically each "device input" has a muxer which selects the input pin, and each output pin has a
muxer which selects the "device output".

What's more interesting is that you might change this in runtime, without need to rebuild anything.

Álvaro


pito

http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,719,895&Prod=CHIPKIT-MAX32
http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,719,896&Prod=CHIPKIT-UNO32
8)
p.

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