AVR or 8051

of

board!

that

other

turning

It was brief, so I will elaborate. First I meant RAM, rather than CODE, but that may be unclear....

With a register-register core, with no direct memory opcodes, all RAM access has a relatively high cost - but the reach of that ram tends to be larger. ie just loading a 16 bit pointer costs 4 bytes in a 16 bit opcode core, (but you can reach 64K bytes), then you need to get/operate/putback that variable => high code cost on ALL RAM variables.

This is the idea of opcode knee, I have mentioned before. In the

80C51, you can access 128/256 bytes in the variable length opcodes. [ Some newer 80C51's have RAM frame pointers, to extend direct meomory opcodes across all on chip RAM, but not many ]

Now, if you want random access into 8K/32K of data, that's not much benefit, but in the embedded microcontroller sector, on chip RAM is commonly well under 1K.

eg a DJNZ opcode in the 80C51 is 2 bytes on a reg, and 3 bytes on any of 128 RAM locations - makes for very efficent loops. Atomic bit access is a natural on a 80C51

You also confirm that RISC was a microPROCESSOR solution, not a MicroController solution. On chip DATA memory was simply not on their radar, but it was very much on the Radar of the 80C51 and Z8 designers, who were building a single chip microcontroller. The Z8 is a good example of register-register 'done right' for a uC, and the Intel 8096 was similar.

For larger memory systems, the ARM will become the natural next 8051, followed closely by the Cortex respin by ARM, which takes a RISC that was designed as a microprocessor, more into the microcontroller space, and to improve memory usage, esp that of RAM.

- ie for a 256K Code and 64K RAM system, one would not choose a 80C51...

Once you bring RAM on chip, (and onto the designers radar), then a register frame pointer makes a lot of sense - as seen in the Z8, the 166, and IIRC, in the SPARC, where they have a nice scheme for partial register overlays, so you use some registers to pass params, and some for local variables.

-jg

Reply to
Jim Granville
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In this formal environment, how do you handle die revisions by the supplier ? - Strictly, that should see a re-cycle, but I am not sure that actually gets done :)

Certainly a migration like AT90S2313 [EOL] to ATtiny2313 should see the full re-approval cycle, correct ?

-jg

Reply to
Jim Granville

"CBFalconer" wrote

Greed and complacency.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer:  Electronics; Informatics; Photonics.
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Reply to
Nicholas O. Lindan

Lack of demand.

From a silicon vendor's point of view, setting up second sourcing takes time and money and cuts into profits. They're only going to do it if enough customers demand it to make it worthwhile.

Given a choice between older, slower, more-expensive second-sourced parts, and newer, faster, cheaper single-sourced parts, people picked the latter in droves.

--
Grant Edwards                   grante             Yow!  Awright, which one of
                                  at               you hid my PENIS ENVY?
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Reply to
Grant Edwards

Hi Jim,

part

months QA

leadtimes

This is an interesting question indeed. I can tell you fersure to some extent we rely on purchasing, which relies in turn on the manufacturers to disclose when they are changing things. If the manufacturer doesn't tell us there's been a die-shrink then we won't know until the ESD damage victims start to roll into field support. We DO contractually require them to give us notice, of course, but in theory they might not.

A part _number_ change automatically triggers full recertification. The testing may well be abbreviated due to similarity, but that never seems to translate into a shorter time period somehow.

Reply to
larwe

Yes it does. The introduction of Lead Free packaging will also mean full reapproval and the migration from the AT89C51 to the AT89S51 needs it as well. It shoudl be fairly safe to stay with 5 Volt parts since migration to denser processes will not happen, but then there will not be price reductions either.

Process shrinks will continue due to the demand for lower prices. When the large companies say they are prepared to accept price increases to keep the parts in production, then they will be kept in production. Prices cannot stay the same, since failing to shrink means that you cannot increase the output in the same fab/equipment.

I hardly think that is going to happen though.

--
Best Regards
Ulf at atmel dot com
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Reply to
Ulf Samuelsson

This is an entirely superfluous comment. If you want to reduce 20 vendors to 1, just use 1 and you've reduced them. Quite simple. And with the 8051 or ARM cores, at least, you have a choice about which vendor's business model fits you better. I've found this to be a particularly important facet in my own As for competition, it stops once the part is designed in unless there is

The "mess with" is only in choosing before that point in time. And having more vendors from which to find a better business match *and* more product options is NOT a disability. One selects one and goes with it, until there is a reason to change -- just as you say. And with the 8051 core or with ARM, at least some of your time (and possibly money) vested in some of the development tools can be saved, if circumstances prevent you from staying with the same vendor (and those reasons can happen no matter the vendor.)

Of course, there are many times that the application itself will mitigate against either of these, on technical grounds. But when there is a fit, it's nice to be able to have some choice in finding more compatible partners.

Jon

Reply to
Jonathan Kirwan

Hi Jim,

Note, he did NOT say 16 bit ACCURATE - 16 bit resolution is easy - but do you believe the answers ???

Steve

Reply to
Steve Taylor

years.

My point is that they're a limited, mediocre pool of parts now and will be a limited, mediocre pool of parts in 25 years.

That's part of it. Another part of it is that if a chip vendor invents a process or peripheral that's really cool, they'll patent the design and copyright the implementation. Another vendor who wants to offer similar functionality at a competitive price point can't duplicate the existing part without paying licensing fees. They are *forced* to be incompatible, or at least different (=> not second-source candidate) if they want to sell any parts.

Manufacturing or designing? The evidence points strongly towards the fact that the only way first-world countries could compete on price would be by lowering professional incomes to third-world levels. The only way this could work is if the entire economy was scaled down in proportion. Not going to happen.

Simple market statistics show that consumers are strongly driven by retail price. You might argue that a locally made product is better, lasts longer, or gets whites whiter than white, but the point is moot if the American DVD player is $100 and the Chinese one is $40.

5-year

True, but I don't think it's likely that Atmel, Philips or NEC are going to go under in the next five years.

:)) Let me guess, he had a bridge on offer as a gift with purchase?

available

Try designing a device that has to last for 600,000 operations off a single CR2032 cell and needs to fit into the handle of a rather fat door key. See how many generic parts there are that can be used in this application.

Reply to
larwe

In article , Nicholas O. Lindan writes

What has he fact that some foreign country can't compete got to do with this? :-)

This is an international NG

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/\ /\/\/ snipped-for-privacy@phaedsys.org

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Reply to
Chris Hills

"Ulf Samuelsson" wrote

_Two_ Years! Imagine That!

You mean 'You will not choose Atmel', and you are correct.

Well, that answers the question of Atmel's long-term viability.

"ASPP" strategy and "ASSP" strategy? That's cool. I'll remember.

Except on Tuesdays, I imagine.

It might, it might (except for Invensys & uWaves). Only time will tell, won't it? Lets resume discussion in the year 2030, shall we?

"Never explain, never complain". Never explain: nobody will understand. Never complain: nobody will care.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer:  Electronics; Informatics; Photonics.
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Reply to
Nicholas O. Lindan

Like human languages, once you really master a couple of them, the next one generally comes fairly easy.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
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Reply to
Spehro Pefhany

Some architectures have (open source) FPGA cores available, which will help long time availability.

Bye

--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
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Reply to
Uwe Bonnes

In article , mc writes

Not true. several manufacturers to tools for the AVR (it's just not many)

As are many 51 tools

Most commercial compilers do. Though check they are not time limited.

Are there any others? there are 100's of 51 dev kits.

No about 40 do for Silicon and a lot more with tools I think you will find that virtually every silicon and IP core/fpga and ASIC manucafurer has a 51 core. The same can not be said for the AVR.

Also the 51 family is being constantly developed. There are man new derivatives and die shrink versions being produced that will of course still all run the 8031 binary from the originals.

There are even versions with JTAG debugging.

The many many tools are:- Free ware , old and new (there are new freeware 80561 compilers being release now. SDCC for one.

A vast area of sharware and inexpensive 52 tools both SW and HW.

Virtually ALL commercial tools manufacturers do an 8051 tool set. Again the same is not ture for the AVR.

Some of the best (safety critical standard) compilers have free versions that are size not time limited that are great for small projects.

there are 8051 tools that run on windows, linux and Unix.

Yes. and LOTS of dev kits most of the 40 plus silicon vendors do their own kits (multiple) and so does almost every other dev kit maker on the planet.

Basically for every 1 of an AVR tool/ code example/ etc there will be

50 in the same category for the 8051 for the 8051

The AVR is single source with comparatively few tools. The same is true of the Philips XA. It does not make them bad parts. Technically both are VERY good.

However unless you are doing this as a hobby there are many other factors involved which may not make the best chip (technically) the right part for the project.

There are many reasons for choosing the AVR or XA. Not all of them are obvious. In theory the Qwerty keyboard is the woest design for a keyboard. This has been known for years but alternatives are rare in use.

Regards Chris

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/\ /\/\/ snipped-for-privacy@phaedsys.org

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Reply to
Chris Hills

Quite true, but the long-term fish-hooks in Soft-CPUs are the silicon supply, and the software tools themselves. There really needs to be a certain 'critical mass' - and the C51 easily meets that.

-jg

Reply to
Jim Granville

help

For CPU + FPGA development, you really want to have coverification, and AFAIK there are two ways to get that; Send a $125,000 check to Mentor, or get the $100 STK594...

>
Reply to
Ulf Samuelsson

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