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Wanted: Embedded Processor Suggestions

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MacGyverS2000

Electrical
Dec 22, 2003
8,504
Looking for any/all suggestions for embedded processors to use for a new project. Here's a list of desired characteristics, but by no means all-encompasing, nor is every item strictly necessary (I'll try to make appropriate notes whenever possible).

1) Inexpensive (Let's say under $15 for a high-MIPS unit)
2) High MIPS (let's say 30+ MIPS, the higher the better, especially if it can be done at low clock speeds, i.e., 1 MIP/MHz)
3) Free software tools (IDE, C compiler, etc.) -- a few hundred dollars is acceptable if the package is powerful. Windows is HIGHLY preferred over UNIX (I'm just not that comfortable with UNIX and don't have a machine built with it).
4) Low-cost hardware tools (JTAG or other in-circuit programmer). Don't really NEED a hardware debugger, but I won't turn one down. Build-it-yourself circuits are completely acceptable.
5) Peripherals MUST include at least one UART and (obviously) a JTAG port (or other programming interface). An ADC would be quite nice, but not a necessity.
6) Generic I/O pins, something in the area of 20+ would be a minimum.

I'm currently working with dsPICs, maxing out at 30 MIPS. Other architectures seem to offer a few more niceties (hardware looping, etc.) for the MIPS, but there's so many to choose from (ARM, MIPS, etc. etc.). I don't need specific part #s, I'm looking more for chip family suggestions... I'll gladly do the research, but I want to make sure I'm not missing out on a good family.

Thanks!


Dan
Owner
 
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The AVR processors seem to fit in nicely. Especially the Mega chips. I am very lucky to be chipping off code for an ARM7 right now. It has a lot more than you ask for - but it is a beauty. 32 bits with 64 bits possible, 60 MIPS 128 kB flash, 64 kB RAM, two UARTs, Double long timers with capture and compare and lots more. And, best of all: I do it in high-level Forth that comes free with the processor if you buy the ready-to use Tiny-ARM (a "stamp" with everything onboard, xtl, 3.3 and 1.8 V regulators, RS232 driver/receiver, JTAG and more). Love it. Will probably be on the high side price-wise for your project. But you save lots of time if you are doing low volume things.

Gunnar Englund
 
WoW Forth? Comes free with the processor? Gimmie dah links skoggs! Hey, what kinds of things are you doing with the ARM7?

macgyvers2000, Moto Coldfire maybe? Some Mitsibishi micros might reach up to that realm.
 
Gunnar,

I never realized the AVR series reached so high in their capabilities. The AT91FR4042 looks quite interesting, even though it's slightly higher than my listed price range (that's acceptable considering the performance from it). I will look into this one... if it's a 1 MIP/MHz chip, that's a real winner. 512k Flash, 256k RAM, 2 UARTs, running at 70 MHz... higher external clock than I would want, but if I get 70 MIPS out of it, I'll be careful with the layout for the power.

I've never even seen Forth code, and I'm not a fan of learning a new language for one project... but I'll consider it. How are you programming them? In-circuit JTAG, external programmer, serial cable? I absolutely need some sort of in-circuit connection.




smoked, I'll look into the Coldfire. Moto tends to have really overprices DSPs for their power level, so I'm leary from the get-go. Hopefully they've done better with the micro stuff.


Dan
Owner
 
I should have paid more attention to the price on that AT91FR4042. It's $21 in singles, which was a bit higher than I wanted. However, pick up 25+ from DigiKey and the price drops down to <$13. That's quite doable for the performance. The whole BGA thing upsets me, though... tough to prototype with. I'll either have to send a few away to have them mounted by someone else or try my luck at a hot skillet approach.

Dan
Owner
 
Moto often seems over the top in price.

I know that a company I onced worked at switched a new model Z80 (Hitachi) over to the ColdFire for more umph and they seem to like it.

Digikey is way over priced for low quantities. Single CPUs have no price logic for production. In fact a lot of PICs you could buy directly from Microchip for less on their web site.

Yes BGA/s suck for design. Getting one or two done is no problem if you have an assembler you run 200 bds a month thru, otherwise you must beg.. and they act bothered. :(

Thanks for the link.

Yes Skogs, few understand the pure beauty of Forth. Ah, runs shivers down my back just typing the word.
 
Hello, I would recommend to at CYGNAL or SILABS ( All mcu they make are INTEL 80C52 clones.
I did try one of them 11 pin device with 8kb flash and
256bytes ram. So I did turn internal clock to 24 -30Mhz
and was able to transmit and receive 115 kbaud manchester
(real data rate was 230kbauds) encoding and decoding all firmware. That litlle chip kicks ass. So you can get 50Mhz and even 100Mhz version of thouse guys. If your application transmits data in packets 250 long try old proven acelerated 8052 of SILABS. It will crunch floating point arithmetic for you. Development kit is $100 with JTAG. Plus you will get KEIL evaluation IDE with C and debugger for windows.
 
I am presently working on a new development board that had been designed around the dsPIC. At the last minute, I changed my mind about the processor. There isn't any one reason for the change, but rather several small reasons. First, I was very unimpressed with the quality of the tools. Second, I received the impression that the DSP core was kludged onto a pic 18F core. Third, I did not feel that the device was a perfect fit for my application and lastly, I discovered that there were much more powerful devices out there for the same amount of money.

Ultimately, I decided upon the TI TMS320F2812, which can operate upto 150 MIPS. In small quantities the TI DSP is cheaper than the PIC. So far, I have been working on the prototype board for about 1 week and I am finding that the hardware is functioning very well.

As far as tools go, they are a little bit more pricey. The code composer studio (compiler) is about $500 (as opposed to the microchip compiler that is $1000). The spectrum digital emulator is expensive at about $2000 (j-tag emulator) however there are third party equivalents that I understand work just as well for about $400.
 
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