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32-bit Processors, Cheap
An anonymous reader writes "Atmel is sampling the first in a new line of 32-bit system-on-chip processors that could spell the death of the venerable 8-bit microcontroller market by offering 32-bit performance at 8-bit pricing. Priced as low as $3 each, the AT91SAM7 chips with ARM7TDMI RISC CPU cores and built-in RAM/flash memory may even be able to run a form of Linux called uClinux. The death of the 8-bit uC market has long been predicted -- sounds like the end is nigh!"
No, not really. That's how electronic components are priced. Unless your doing some custom one-time job, bulk pricing is how you price your build-of-materials. In fact, many times the actual price is even lower than the list price. Especially if you order larger quantities.
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The Atmel company has always gone to great pains ensuring that their chips are compatible. That's very smart, because developers can switch chips with little or no adjustments.
This is a pretty big, fundamental change. But based on their repuation, I think Atmel will provide the maximum amount of compatibility possible without being silly about it.
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Actually, I don't see much demand for these "medium speed" controllers. For control applications, they're overkill most of the time, and for multimedia stuff, they're too slow/small.
:).
I've been playing with Atmel's 8-bit line. What makes these chips nice is that they're fast enough to do a lot of things in software that would otherwise require dedicated hardware (PWM, audio input/output/processing), while still leaving enough cycles free to do the high-level control work. Atmel also has a habit of throwing everything including the kitchen sink as peripherals into the controllers, making them very versatile. Yet, you can clock them down and turn off peripherals you don't need in order to get the same kind of power consumption you'd get with a simpler chip, when needed.
From Atmel's point of view, this type of architecture makes sense - instead of 20 similar lines of microcontrollers with different peripherals, they have two or three (for different voltages, mainly).
From a widget designer's point of view, this saves on learning curve and equipment (become familiar with and buy equipment for one or two families of device instead of dozens), and gives them a chip they can use as all-purpose glue with only a modest hit over an application-specific solution.
In summary: Go Atmel
[As for 8 vs. 32 bits, the 8 bit family will likely always be lower power for digital functions, due to fewer nodes being switched per operation.]
Having an inexpensive 32 bit uC is great. How much are the development kits? 500$?
The basic stamps are great. For an 8-bit 10kHz platform that runs PBASIC.
The SX & PIC chips are great for 8-bit systems that run at a few MHz (sx up to 50 MHz), that are programmed in assembly.
The TI MSP430 is a great 16-bit platform that runs at 8MHz, programmed in C/C++ (in a few weeks they will probably unveil a 25MHz version). They also include lots of things that I don't like to have to add-on myself. (12-bit A/D & D/A, op-amps, HW uarts/I2C, and so on)
There would definitely be a market for these things, but I'd like to see if they can match development costs for small developers. It seems to me that a key is opening development to the masses. That's what impresses me about the few I listed above. Dev kits from TI are 100$, and from Parallax are
I use uC's for embedding scientific devices onto smaller/cheaper/faster chips. That's great. Now for me to be able try it, and learn to use it, I can't go buy an expensive dev kit. Regardless of the end cost of the chip, I prefer to pay 30-50$ for a board with a chip, that I put in a box and use, than a uC with smt leads that I can't get to work in place without a few hundred to thousand dollars of dev costs.
1) High code density: Even if you need more instructions to perform an operation, if the instructions are only 8 or 16 bits wide, you wind up with a smaller executable. Hence, you need fewer bytes of ROM to store the firmware. And if a lot of your data is byte sized anyway, (processing strings, or reading an 8 bit ADC or setting an 8 bit PWM) the code may be smaller still, since there is no byte packing/unpacking into a 32 bit space required. (Incidentally, this is a major problem with 64 bit and VLIW computing.)
2) Power consumption. An 8 bit processor has only 25% the bus width of a 32 bit processor. Registers, instruction decoders, and ALU are 25% as complex. Ergo, for the same manufacturing process and clock rate, an 8 bit core will always consume a lot less power. If you are trying to run an algorithm off a watch battery, this really matters. That is chiefly why the venerable 8 bit PIC with its horrid assembly code, continues to be popular.
3) Less die space. Same reasoning as above. if you are doing an ASIC and can get away with an an onboard 8 bit controller core, why would you waste silicon using 32 bits?
3) Backwards compatability, ability to run legacy code. Even in embedded systems, stuff gets reused. 95% of you will be reading this on an x86 PCm which happens to trace back to a 4.7 MHz 8 bit ancestor found in the original IBM PC, the 8088.
What it ultimately boils down to, is selecting the right tool for the job. And there will always be a niche somewhere for humble little lightweight 4 and 8 bit controllers.
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Don't forget Automobiles: Engine, ABS, HVAC, and Airbag controllers all still use (well for the most part anyway) slow, cheep 8-bit micro-controllers.
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