Sometimes it's hard to justify the use of AVR's..

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Make no mistake, I love AVR's, and I use them whenever I can.
But...

I recently found out about this 64pin tqfp ARM7 (32bit RISC you know..) based MCU with 128kB built in flash, 8k SRAM, PLL, and JTAG interface.
Maximum clock frequency: 80MHz (!)

Can you guess the price?
About $4-5 (!!!)

Sometimes life is hard...

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I'm using mega8's in a new design and I think I can justify the use of MLFs. If I do end up using them, I'll help you get a hold of the coveted MLF mega8s d:) I know you want them d:D

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pepsi: *LOL* Yes, the Mega8 MLF is very nice :)

I don't think it's possibly to get them in quantities <10000 right now thou... demand is higher than supply... long lead times...

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Which ARM chip? Manufacturer?

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DigiKey gave me a quote on 500 of them, lead time of 18-20 weeks

the mega8 mlf's that is

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Samsung S3F441FX

And I was wrong... it's 256kB internal flash, not 128kB. :)
Also it has got six 16bit timers!

The chip is designed for use in harddrives. That's why it has got so many timers.

Maximum recommended operation frequency is 40MHz, but according to datasheet fck/vcc diagrams it should be able to do 80MHz if vcc is kept at 3.6V.

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AmPz,

About this ARM...

I can't use a breadboard at 40 MHz. Does it run slower? Or will I just need something that approaches a pro development environment just to get a program to run?

Speaking of development environments, what sort of a setup does the ARM require? Is it an affordable cost?

Please tell me a little bit about the ARM, aside from telling me about the device itself. If I can't work with it without going to the poor house, first, then it matters not how powerful the device is. ;-)

Could Atmel's AVR be better? Sure, absolutely. But then I can work with this thing also. Atmel gave me enough to work with without sending me to the poorhouse. Studio 4 was awful, but 3.55, so far, is going just fine. The STK500 had a very hot regulator. I cooled it with a heatsink. Problem solved. This is what I mean by "I can work with it." Could it have been better? Yes. Could it have been better for the price and the workability? Honestly, no, no I don't think so.

So tell me about the ARM. How will it work for me? This device, as powerful as it may be, sounds like it's made for that which is not me. ...at least so far that is.

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This ARM has a built in PLL, that means it only requires an external 4MHz clock source. The PLL then multiply that frequency by any constant.
And yes, you can run the ARM at any frequency.. if you want.

You don't need much to get started with ARM... A JTAG interface, a debugger and a assembler and/or compiler.

There are simple JTAG interfaces you can buy or build (similar to the AVR ISP cable)

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Who makes this ARM7 and who sells it for such a low price? I would love to know. Do you have a link to a datasheet? I'd like to compare it to the Mega128 and see if it's all it's cracked up to be. For that price there has to be a "gotcha".

Thanks.

Jeff

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> I'd like to compare it to the Mega128 and see if it's all it's cracked up to be.
> For that price there has to be a "gotcha".

Like you can't get hold of them or maybe they don't exist.

AmPz hasn't even given us the name of the manufacturer let alone part number.

Jon

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Jeff/all,

who makes it?
http://www.arm.com/

They make the genuine ARMs, but they also license their cores to other people (intel, atmel, samsung, just about anyone really)..

BUT! And this is a big BUT

Check out the cost of the compiler/IDE ;-
http://www.arm.com/websales/Onli...

Yes you did read right $5,500 for the IDE, oh and another $500 for the libraries..
The student version is about $3,500 when I enquired (though I wasnt a student)

Shame, if the IDE was more reasonable cost, Id think about it..

Even the Atmel arm only comes with a 30 day evaluation license for the ARM IDE. http://www.atmel.com/atmel/produ...

Paul

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here is the link to the data sheet:

http://samsungelectronics.com/se...

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Jon,

My distributer here in the UK has the MEGA128's...

Paul

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AmPz,

"This ARM has a built in PLL, that means it only requires an external 4MHz clock source. The PLL then multiply that frequency by any constant."

A breadboarder would have to slow down the port accesses, but indeed that PLL does help.

"And yes, you can run the ARM at any frequency.. if you want."

Ok, it sounds like the freguency problem is solved.

"You don't need much to get started with ARM... A JTAG interface, a debugger and a assembler and/or
compiler.

There are simple JTAG interfaces you can buy or build (similar to the AVR ISP cable)"

If I build I want to build knowing I have the core pieces already in hand and working. I consider core things to be an assembler and a programmer. I don't want to build either of those, and I'd want both of those available from the manufacturer for a reasonable price. But that's the kicker. Is the ARM available in a DIP? If not, then there will be considerable expense involved in 1) manufacturing the programmer (which drives up the costs to me as the purchaser of the programmer) and 2) adapting the ARM to a breadboard environment (I'd need not just a programmer but a development interface.)

Then, assuming these problems are solved (big assumption), service (which can be application notes) and an emulator would be icing. This ARM would be competing with my current setup with the AVR. Could it really compete?

(Incidentally, I don't care so much about the RISC architecture, and I'd prefer CISC, yet I've gone with the AVR -- my first experience with RISC -- for the simple fact that what I want to do (from what I've found) cannot be done for less cost than my current AVR setup.)

Then there's one other thing about the PLL, before I leave the subject, has the loop filter already been designed? I do not relish the idea of designing my own loop filter. This ARM is employing a synthesizer, which means the loop filter should already be handled, but I ask just the same.

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AmPz,

Understand that I'm not trying to give you a hard time -- these questions I raise are quite sincere. I'll give anything a fair shake, but the ARM solution does not (yet) sound like a solution that I can work with for a cost comparable to the AVR setup. In other words, let Studio not work somewhere crucial, let the STK500 have a brick wall bug, or let the JTAG interface be found to have a security hole that I cannot accept, and my development environment can change (it'd be much to my disappointment.) But so far I'm still with the AVR.

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Anyone look at the power required to drive the arm at 40 MHz? I used to work with the ARM's in a cable modem chip, it was very full of function, but sometimes it's like using a sledgehammer to drive a thumbtack in... overkill.

You do know ATMEL makes chips with ARM's in them right? the AT91 stuff.

It's hard to compare apples to apples here.... you have to look at EVERYTHING like can the pins on the ARM source/sink as much current. These AVR's are pretty strong.

If you think the ARM will do what you need it to do at the price you find acceptable in the power consumption range you need (phew long run-on), then go arm. I stick to AVR's cause they fill my design requirements and have a little gusto to spare.

My opinion.

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I don't see what's so hard about it. The almost non-existent Samsung MCU with no support and no help with a $5500 compiler and IDE, versus the Atmel chips with multiple hardware choices and support from many sources. Atmel even provides the AVStudio for free too.
Besides Atmel has ARM licensed CPU's too, and they're priced good too.

If you even get a MCU from SAMSUNG the odds of being able to program it
will wear you down. It won't be such a deal after all that trouble.

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Easy now.....

Of course there is a GCC for ARM. Strange that nobody have mentioned that before.
I've been working with ARM-GCC for more that a year, and it works perfectly.
Many PDA's and similar devices use an ARM-core based processor.
And many of them run Linux - compiled with GCC for ARM.

/Jesper
www.yampp.com

/Jesper
http://www.yampp.com
The quick black AVR jumped over the lazy PIC.
What boots up, must come down.

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Oookay, I'll answer one person at a time..

Jeff Green:
"Who makes this ARM7 and who sells it for such a low price? "

As I've already said, Samsung makes it.
***
Jon Schneider
"Like you can't get hold of them or maybe they don't exist. AmPz hasn't even given us the name of the manufacturer let alone part number."

Obviously you didn't read this thread very carefully, I've mentioned both the manufacturer and the part #no
***
paul maddox:
"Yes you did read right $5,500 for the IDE, oh and another $500 for the libraries.. The student version is about $3,500 when I enquired (though I wasnt a student) Shame, if the IDE was more reasonable cost, Id think about it.."

The GCC compiler and debugger for ARM is free.
Tell me... what free compiler is there for AVR? ;)
There are very expensive IDE's for AVR too, that doesn't mean you have to use them.
***
Ed:
"If I build I want to build knowing I have the core pieces already in hand and working. I consider core things to be an assembler and a programmer. I don't want to build either of those, and I'd want both of those available from the manufacturer for a reasonable price. But that's the kicker. Is the ARM available in a DIP? If not, then there will be considerable expense involved in 1) manufacturing the programmer (which drives up the costs to me as the purchaser of the programmer) and 2) adapting the ARM to a breadboard environment (I'd need not just a programmer but a development interface.)
Then, assuming these problems are solved (big assumption), service (which can be application notes) and an emulator would be icing. This ARM would be competing with my current setup with the AVR. Could it really compete?
Then there's one other thing about the PLL, before I leave the subject, has the loop filter already been designed? I do not relish the idea of designing my own loop filter. This ARM is employing a synthesizer, which means the loop filter should already be handled, but I ask just the same.
"

You haven't worked much with JTAG, have you? The JTAG interface is as simple as the AVR ISP cable, but as powerful as any ICE!
You can program your CPU via the JTAG interface, and you can use the JTAG interface for ICE debugging. No, the ARM doesn't come in DIP (that would be some DIP... 64pins..), so what? if you are a breadborder, etch a small board just for the ARM, solder the ARM to that board and attach that bord to your breadboard. Not costly at all. The ARM can be programmed ISP via the JTAG interface, so a dedicated programmer is not required.

So you see... the only hardware you need is a JTAG cable, that can be bought fairly cheap, or built for even less. As for the required PC software... use GCC!

Yes, the entire PLL is internal.
***
Earl Bollinger:
"I don't see what's so hard about it. The almost non-existent Samsung MCU with no support and no help with a $5500 compiler and IDE, versus the Atmel chips with multiple hardware choices and support from many sources. Atmel even provides the AVStudio for free too. Besides Atmel has ARM licensed CPU's too, and they're priced good too. If you even get a MCU from SAMSUNG the odds of being able to program it will wear you down. It won't be such a deal after all that trouble."

As already mentioned... Have you forgotten about GCC?
I've worked with this ARM CPU... And it's really easy! The JTAG interface let you do anything! read/set registers, read/program SRAM or flash, singlestep, etc. Anything a ICE can do.

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AmPz - Don't get too worked up. People seem to have taken your comments personally and responded like you kicked their dog. Get a life people. It's just another tool. You may have your favorite hammer, but the yellow one with a bigger head is useful too.

I also noticed that many comments came from the side of the hobbyist. Feel free to ignore their comments. DIP? Who the hell cares. Great for hobbyists, irrelevent for production.

I didn't know GCC supported ARM. That sounds really interesting. Do you have a source for hobbyists (yes, I'm one of them with AVR) for the samsung chip?

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AmPz:
Hmm, that JTAG cable... is it the same as to avr? Or do you need a special cable?
Where can I find information on how to build one myself?

Is there (free) assemblers for ARM too? Or is it just a waste of time using assembler on such a powerful machine?

/Anders

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ravton: I still love AVR, and I still use them for most of my projects. Hobbyist source of the ARM might be a problem, But if you represent a company it shouldn't be that hard to get samples.

arune: Unfourtunately I've never worked with AVR's with JTAG interface, so I don't know. I don't know for sure that schematics for the cable are available on the net, but it should be. I have a JTAG cable called "Wiggler" from MacGregor Systems here that I opened up, and all it contains is two 3-state buffers (74hc244 if I remember correctly).

Of course there are free assemblers too, however, the complexity of ARM instructions make it hard to write better code than the compiler can produce...

For example, with ARM you can do stuff like the following in one single cycle instruction (!!)
If carry is set, then add r0 with r1<<14 and store the result in r2

Very powerful.

Still, it's fun to write asm code.

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Sorry for getting excited.
But I always like a "reference point" when I am designing and programming things. A PCB with Chip and software that can program it successfully. Even it it is only blinking LED's.
But before you cough up $6,000.00 for it, make sure the rep can demonstrate that it can successully program and work with the processor you want to use.

I have stuff on the shelf from a past project (cost us over $8,600.00) where the manufacturer had released a chip before the software caught up to it. Thus forcing us to use a different processor.
I also like some modicum of support that doesn't entail going through your vendor who goes to the distributor who goes to the manfacturer to get a question answered. Something always gets lost in between.
When I was younger the excitment about being on the bleeding edge and exploring and opening new frontiers was fun. I don't like doing that so much anymore, I guess I'm getting old.

The ARM based chips are pretty neat though. A single chip solution makes for a really powerful MCU do do stuff with.
But 128k of flash memory with a 32bit processor may not be as efficient as a smaller processor like the Atmega128 in some cases. A small program for a 32 bit processor may use up twice or more of the memory than that of a 8 bit processor.
So it depends on what your wanting to use it for.
But then dealing with 32 bit math is a lot more fun than trying it with a 8 bit processor. And it makes reading the new 24 and 32 bit ADC's really easy too.

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Earl: I don't consider ARM7 to be "the bleeding edge"... It's a proven core that has been around for quite some time now, and there are probably hundreds of different CPU's and MCU's that are based on it. It's just a good 32bit core without any floating point or ultra-deep pipelines.
About 128k flash memory... If you worry about space efficiency, then why don't you just switch the ARM to thumb mode? ARM7 can work in two modes... ARM and THUMB mode... THUMB uses 16bit instructions. Thumb is good if you have to save flash space, or if you use a external flash memory with 16bit databus. (32bit instructions would require two readcycles per instruction, resulting in a quite big performance penalty)

The AVR use 16bit instructions too you know.

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AmPz,

I know how you feel. I am interested in using a ARM7 part for some of my more advanced projects, but I have not found a good ARM7 source. I am going to check out your Samsung recomendation.

Also, I have been receiving a lot of literature from TI for their MSP430 family of 16 bit embedded prcoessor. The MSP430's low-power architetcure seems interesting, and TI has great support. But, for my son's robot controller (Hobby application), I initially decided to use the Atmel Mega32.

After getting halfway through the board design, I got frsutrated with the local Atmel rep who never does anything he promises. So, I deleted the Mega part from my design and replaced it with a MSP430F147.

Not only is the part cheaper at Digikey ($9 compared to $16), but TI sent me three "Free" working samples of the F147, F147, and F149. Cool...Free is good :)

So guys, the moral of the story is keep a open mind. Sometimes there is a better solution waiting to be used for your design.

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Hi everyone,

I understand that the gcc compiler is free, which is good. However, what about the emulator environment? I've been using AVR Studio 3.xx, which has fairly good support for emulation and the different formats it supports for third party devices (coff etc). Does anyone know the name of the emulator/simulator, whether its also free, and where it can be downloaded?

Thanks.