Understanding the AVR naming convention

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I get that the first digit is flash but I haven't figured out what the remaining digits are for. For example, what does the 313 in tiny2313 refer to?

Also, I see many models with a "P" after the name with very little difference in features in the parametric table (just the A/D converter). What's that all about?

And while we're at it, what makes an AVR an automotive AVR or a lighting model or an LCD model? The description for the lighting says it's specially designed for lamp ballast but, how?

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Beats me too batman! Automotive usually has extended temperature range and more testing, lighting has DALI uart feature and specific pwm features applicable to lighting control, lcd models have support for driving lcd glass and P I think is 'picopower' although I may be corrected on this. I use the mega128 and 2560 -128 being 128k flash and 2560 being 256k flash - what the last 0 is beats me.

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Back when I was your age and there were printed data books, the 4-digit AVR model numbers followed a scheme that quickly broke down.

An example was the AT90S4433, with a less-popular smaller sibling the '2333.

That numbering was largely abandoned with the mega & Tiny categories, circa 2000.

Again the naming quickly broke down. One of the first Mega families included the Mega163 and Mega323, which soon became the Mega16 and Mega32, to go with the Mega8 and Mega64 and Mega128. That numbering gave the flash size in kbytes, and no-one could ever need more models than that, right?

Well, look at how many AVR models there are now. So we have the Mega(x)8 family with the same pinout, and Mega48/88/16/328 models. The first number is still the flash size. There are several other families like that, the 4, 5, & 9 families.

But the bigger ones have overlap on the 64 & 100 pin models. And the AT90 prefix still lives in the AT90USB and AT90PWM models. Summary: the first number after the prefix is (usually?) the flash size, but don't count on the rest.

Now, let's get down to the P suffix models. The low-power capabilities of the AVRs have evolved over the years, and the latest models are designated P for PicoPower. Aside from the sleeping brownout which is invisible to the programmer, I see little difference in the P chips vs. the V chips from a programming point of view. Go to http://www.atmel.com/dyn/product... and click on PicoPower on the left for a description.

There may be some slight differences in features between P & V but I don't know of any significant changes in A/D as was mentioned.

For "ballast" and such, you have to drill down into the "Lighting AVRs" at the link I gave and see what documents and brochures are linked. Certain models do have features targeted at a specific application area.

For the automotive AFAIK it deals with being certified over extended temperature range(s). I was told that these models won't show up in distribution as a matter of course.

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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In the case of the 2560, it's to designate a different family than the older 128. And whether there is an 0 or 1 at the end refers to the pin count

Quote:
64KB/100-pin version: ATmega640
128KB/64-pin version: ATmega1281
128KB/100-pin version: ATmega1280
256KB/64-pin version: ATmega2561

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Appreciate all the info. Thanks!

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Ok, I've tried googling more info on this but haven't been able to come up with much. Right now I'm looking at ATtiny24/44/84 vs. ATtiny24A/44A/84A. After looking @ the first page of the data sheets (where features and such are listed) I cannot see hardly any difference. It seemed the *A versions are maybe just newer? This judgement is based on the copyright year of the datasheet (probably not that good of indication) and some revisions to the datasheet.

I'm mainly wondering this because I made a little breakout/eval/dev board for the ATtiny24/44/84 and the *A series may be slightly cheaper. I'm wondering if I can use the same board/programmer/avrdude commands to program them? Basically will I notice a difference? From what I've found... I won't.

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I didn't know there was any numbering system

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut. 

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Quote:

It seemed the *A versions are maybe just newer? This judgement is based on the copyright year of the datasheet (probably not that good of indication) and some revisions to the datasheet.

https://www.avrfreaks.net/index.p...

Atmel have produce migration notes for almost all nnnn to nnnnA transitions. As you'll see all that's really affected are electrical parameters - mainly reduced power consumption.

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Thanks WrightFlyer!

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You're welcome

(a rose by any other name would smell as sweet ;-))

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oops the multiple personality pill is no longer working....

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

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