inexpensive way to get into ARM?

"Leon Heller" wrote in news:41b9c85a$0$16582$ snipped-for-privacy@news-text.dial.pipex.com:

One more question - it seems that the Philips chips are the most reccomended, but is there any particular reason why? Looking around, I see that there are various other manufacturers of ARM devices, specifcally Analog Devices and Atmel (and I expect there are varios others as well). What makes them so different? I mean as I've said - my primary embedded programming experience is with Atmel AVR microcontrollers, and with them you pretty much choose the chip that has the features you need. Moving code from one AVR to another is a fairly simple task in most cases, at least in my experience. I mean it seems to me that once you know how to program one AVR, you can program for most any AVR. Is this not the case with ARM devices? Is there really that large of a difference between chips and manufacturers? Thanks,

-Michael

The Philips ARMs run at nearly 60 MIPS from flash, and I think that they were the first of the single-chip ARMs; that is probably why they are so popular. Also, there are lots of low-cost boards available for them.

The new devices from Atmel and ADI are similar to those from Philips, and all ARM chips with the same core are identical from a software point of view.

Leon

Two main reasons, I suspect. - the first is simply that they were in the game early. The first (I was aware of anyway) small package arm microcontroller (IE no external bus). - Probably related to number one, they have developed a large self supporting user community.

The three other small ARMS I'm aware of (Analog Deveices, ST and Atmel) don't appear to be generally available yet but samples are. They are close enough to available that one of them may have started shipping since I last checked.

Robert

devices,

Philiops has been out there with single chip flash processors for a few more months so people have more experience. Atmels SAM7S started sampling two months ago so not so many have expericene.

If you go with the Atmel chips, you have a migration path up to the 200 MIPS AT91RM9200. The peripherals have changed somewhat since the first release of the AT91M40400 but there are much more similarities, than differences. You have a hard time doing that with most other companies ARM chips.

If you want to work with low end ARMs, thne you cannot get anything smaller (and cheaper) than the AT91SAM7S32. There are free GNU C compiler and a Free IAR C compiler for it. (Limited to 32kB; but who cares, when you only have 32kB ;-) There are some new fancy low cost tools coming out in January from the AT91 Support group but cannot tell more yet.

That is a very good question. I was looking for small ARM chips about the time Philips announced their chip and they were not the first. Atmel has had some good products for awhile and OKI had single chip parts in production at that time. But no one seems to notice the OKI parts while the Philips parts took off like a rocket in the designer groups. Both parts are worthwhile. So you be the judge.

If you're interested in getting into ARM assembly language, but not yet into JTAG or devices, etc, I would recommend looking into

The GBA has an ARM7TDMI core. There is an emulator called VisualboyAdvance which runs on both Windows and Linux. You can buy a programmable FLASH cart for the GBA for about $100 and GBAs are $80.

It makes it really easy (and fun) to get into ARM programming, interrupt handling too. More interesting than flashing LEDs and writing characters out of a serial port.

Once you're familiar with the instruction set (both ARM and THUMB), you can graduate onto a more serious platform.

The sites I've listed provide links to GBA information and a pre-compiled GCC toolchain.