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AVR looking weak against TI and Cygnal

Discussion in 'Embedded' started by Chris Carlen, Dec 18, 2003.

  1. Chris Carlen

    Chris Carlen Guest

    Greetings:

    Of course we haven't seen them yet, but when 25MHz MSP430s come along,
    with their fast 12-bit A/D and D/A capabilities, combined with the
    Cygnal 100MIPS 8051 derivatives with fast 12-bit A/D and D/A as well,
    the AVR with its 16MIPS and only 10-bit A/D slow 15ksps with no
    dedicated D/A hardware, is looking a bit on the meager side.

    Is Atmel going to try to compete with these Cygnal and TI offerings
    (even at 8MHz, the 16-bit MSP430 core is of similar performance to the
    16 MHz AVRs, lower power, and much better analog IO).

    I'd really like to see some 33-40MHz AVR offerings, and some with
    substantially improved A/D like 12-bit 100ksps, and some with 2 12-bit
    DAC channels.

    Whadaya think? What is Atmel's plan regarding what part of the uC
    market they want the AVR to occupy? Do they want it to be a low-power
    (though higher than MSP430) mid-performance uC only, or to be able to
    compete on all tiers?

    Good day!

    --
    ____________________________________
    Christopher R. Carlen
    Principal Laser/Optical Technologist
    Sandia National Laboratories CA USA
     
    Chris Carlen, Dec 18, 2003
    #1
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  2. Chris Carlen

    Leon Heller Guest

    There is also the Philips LPC2100 ARM family: very easy to use, 60 MHz
    operation (54 MIPS), 32 bits, plenty of I/Os, lots of peripherals, and <
    $10.

    Leon
     
    Leon Heller, Dec 18, 2003
    #2
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  3. Cygnal have 1MSPS 16 bit ADC, and have 24 bit ADC comming.
    As well as the MSP430, TI also have the [BurrBrown] MSC12xx family,
    with 24 bit ADCs, and 16 bit DACs.
    Also from TI, are sub $10 FLASH DSPs, with 12 bit/6MSPS ADCs

    High performance Analog is non-trivial, and tends to come only from
    companies with a proven track record in ADC designs.

    Raw MHz is less a challenge, and tends to come from normal shrink
    timelines and/or more efficent FLASH Bandwidth design.

    Atmel _do_ have a niche in GHz ADCs, but I'm not sure you'd paste one
    of those next to a AVR :)
    (Don't forget the up to 64K Bytes of RAM..)
    Certainly these Philips & TI 32 bit offerings will put real pressure
    on the upper end of 64-128K byte AVRs/PICs in the long term.

    -jg
     
    Jim Granville, Dec 18, 2003
    #3
  4. Chris Carlen

    CBFalconer Guest

    I think one salient point of the Cygnal (and other) devices is
    their membership in the ubiquitous 8051 family, with many
    suppliers available.

    The problem with the MSP430 (and others) is their single supplier
    condition. I think TI would do well to license the designs to
    other manufacturers, and aim for a similar wide family.

    We never had any qualms in the old days about using the 8080,
    8086, 8088, 8049, 8051, z80, 6502 and derivatives therefrom,
    because multiple suppliers were always available. However the
    Motorola competition (6800, 6808, 68000) fell because of
    availability.
     
    CBFalconer, Dec 19, 2003
    #4
  5. where did you get this quote?
    EUR 12 (approx. $15) is what we get from our distributor for 250 pcs
    tray (6-8 weeks for delivery outch!)
    EUR 15 (approx. $20) for smaller quantities

    also you can add: immature chips (probably with lot of bugs on the
    first releases - philips is hurrying to throw on the market chip but
    they still have no completely datasheets written), no code protection
    scheme i.e. everybody can copy your design ... at this point LPC2100
    is still great entry level for learning ARM7 architecture, assemler
    etc, but IMO for now can't be considered for any serious job

    Best regards
    Tsvetan
     
    Tsvetan Usunov, Dec 19, 2003
    #5
  6. Chris Carlen

    Leon Heller Guest


    I paid 7.75 GBP each (about $13) for 20 off LPC2106 from my distributor:
    Silica/Avnet, here in the UK. The pound is strong against the dollar at
    present, which helps. I think the '2104 is under $10 in quantity, here.
    How about me buying your chips here and selling them on to you, I can
    probably get 100 pcs immediately. :cool:
    It's still a very nice chip, and should prove *very* popular, IMHO.

    Leon
     
    Leon Heller, Dec 19, 2003
    #6
  7. Chris Carlen

    Unbeliever Guest

    I beg to differ. Having used the MSP430 for some time, I recently
    benchmarked it against the AVR for an IP stack app. The AVR won hands down.
    The MSP430 might be comparable to the AVR for 16 bit stuff, but an 8 bit
    app. is much faster on the AVR. The problem is that an MSP430 averages
    about 4 cycles per instruction, giving about 2 mips for an 8MHz part (6 and
    a bit for 25MHz) whereas the AVR averages about 1.8 cycles per instruction
    for about 9 Mips. The MSP430 is a fantastic low power processor with a
    bunch of peripherals available but its speed is not quite in the same
    ballpark as the AVR.

    Now the ARM is a different container of herrings altogether.

    Cheers,
     
    Unbeliever, Dec 19, 2003
    #7
  8. The FPSLIC will of course get you 25 MHz today, and probably 33-40 MHz
    when the 0,18u chips are out next year.
    The ATmega8 is running 33 MHz in the lab so it does not seem to be totally
    unfeasable
    to release higher speed parts.
     
    Ulf Samuelsson, Dec 19, 2003
    #8
  9. Chris Carlen

    Chris Carlen Guest

    Hi Ulf!

    Yes, the FPSLIC is a bit better. But I guess I'm more interested in
    seeing better analog IO, including DACs on the plain controllers, as
    well as a moderate boost in speed. Even 25MHz would be nice for the
    time being.

    Is the mega8 at 33MHz just an overclocked standard mega8 (whatever 0,NNu
    process you are using for production megas right now), or is it a new
    process? Does it mean Atmel actually intends an upgrade to the speed
    capabilities of the AVR-mega family anytime soon (or later)?

    Thanks for input.

    Good day!

    --
    ____________________________________
    Christopher R. Carlen
    Principal Laser/Optical Technologist
    Sandia National Laboratories CA USA
     
    Chris Carlen, Dec 19, 2003
    #9
  10. Chris Carlen

    Chris Carlen Guest

    Hmm. I see. Thanks for the input. I haven't actually worked with
    MSP430, but have been considering that if and when a 25MHz MSP430
    becomes available, to weigh it against the AVR as a possible replacement
    for some signal synthesis applications that are pushing the AVR to it's
    limits.

    Perhaps I'd be better served by just a faster AVR, though I like the
    integrated 12-bit analog IO on AVR's competitors. Since I know and
    *really* like the AVR architecture, and the tools are cheap and easy,
    I'd much rather stick with it than say, work with the Cygnal parts.
    8051, blech! I don't care that the 8051 is big-time, since I do mainly
    laboratory instrumentation where easy=fast results is more important
    that product margins for million unit sales.
    Yes, and it's something I'll have to delve into at some point. I was
    actually hoping the Motorola 68000 family stuff like Dragonball would
    remain of similar popularity to the ARM, but that doesn't seem to be the
    likely outcome. I figured the 68k assembly language would be a cinch to
    learn, compared to ARM (I figure I will need to understand the assembly
    to work competently with any CPU, since there are times when I have to
    step through the compiler output to make sure it's doing things right).
    But now I feel it might not be worth the effort to learn the 68000
    considering it seems to be fading and ARM taking over.

    Good day!



    --
    ____________________________________
    Christopher R. Carlen
    Principal Laser/Optical Technologist
    Sandia National Laboratories CA USA
     
    Chris Carlen, Dec 19, 2003
    #10
  11. I paid 7.75 GBP each (about $13) for 20 off LPC2106 from my distributor:
    Silica have no rep for Bulgaria, I sent request to the quoted office
    in Slovenia on their web page and never got reply, same is with Arrow
    which is also quoted as their distributor, it seems that Philips have
    no enough stock to cover even the initial interest they made with the
    LPC2100 buzz.

    Best regards
    Tsvetan
     
    Tsvetan Usunov, Dec 19, 2003
    #11
  12. Chris Carlen

    David Brown Guest

    I've used both the AVR and the msp430, and I like both architectures - but
    the msp430 is definitely nicer to work with both in C and assembly. The avr
    is more elegant in some ways, resulting in code that runs very close to one
    instruction per clock. But the msp430 has a very flexible instruction set
    that has two big advantages over the avr, especially for C programing - it
    is 16-bit wide, and it has a single flat memory space. The avr's Harvard
    architecture may be faster, but the single memory space is vastly easier to
    deal with (no more complications with strings and data in flash).
    The 68k programming model is still going strong. The 68332 microcontroller
    seems to be pretty much immortal - no matter how much Motorola says they
    want people to switch to the ColdFire and/or the MPC, the 68332 is still
    popular. Then there is the ColdFire family - it is the same programming
    model as the 68000 (to within about 90%, anyway), but a new and more
    efficient implementation of the core, and it is very popular.
     
    David Brown, Dec 19, 2003
    #12
  13. Hi Ulf!
    Yes, Analog and built in Flash would be a nice addition to the FPSLIC.
    The new 58.8k process will make that possible. - No promises though.
    Overclocked standard issue 0,35 u Mixed signal process running at 3.3Volt.
    Same process as everything else.
    Does not mean anything unfortunately.
     
    Ulf Samuelsson, Dec 19, 2003
    #13
  14. I agree about the problems with putting strings and data in flash!
    While it's easy enough to do, it does make it difficult to write
    general purpose, portable C that is not littered with special macros
    and functions to specify flash or ram storage.

    Isn't there a problem with the MSP430 and word/byte accessing? See the
    last paragraph of this link from the msp-gcc documentation:

    <http://mspgcc.sourceforge.net/manual/x213.html>

    Perhaps this is just a limitation of the msp-gcc port.
     
    John Devereux, Dec 19, 2003
    #14
  15. Chris Carlen

    David Brown Guest

    No, that's exactly the same as with every other 16-bit (or more)
    microcontroller - some peripherals need to be accessed as 8-bit and others
    as 16-bit to work correctly, while others are freely accessible as either.
    All you need to do is make sure the peripherals are declared properly (i.e.,
    volatile unsigned chars or volatile unsigned ints), and the compiler fixes
    things correctly. It applies to all compilers - it's just that the msp-gcc
    manual gives a lot of information about that sort of thing.
     
    David Brown, Dec 21, 2003
    #15

  16. The text seemed to imply that the problem was more general than that,
    but now I am not so sure! If it is just peripheral access that is
    affected, then that in itself hardly stops the processor "supporting
    strict C compliance" as the author stated. I read it to mean that
    arbitrary structures in memory cannot be copied byte-by-byte.
     
    John Devereux, Dec 22, 2003
    #16
  17. Chris Carlen

    David Brown Guest

    I think it is just that C has no standard way of dealing with specialised
    access for peripherals. Even declaring things as volatile does not force
    the compiler into specific behaviour, nor does it force the compiler to use
    particular access widths. So all the manual is saying is that the
    peripherals in the msp430 cannot be accessed in a pure standard C way.
    Arbitrary data memory (ram and flash) can be accessed arbitrarily.
     
    David Brown, Dec 22, 2003
    #17
  18. Well that's no problem then, that makes the msp430 a very nice "C
    friendly" micro. A big improvement over the AVR in that respect I would
    say, with its awkward handling of flash data.
     
    John Devereux, Dec 22, 2003
    #18
  19. Chris Carlen

    David Brown Guest

    And that would lead us back to my original point - for C programming, the
    msp430 feels more natural than the AVR. In assembly, both work well, and I
    find I write (or wrote - I use mostly C now on both chips) accurate code
    with a very low error rate on both chips.

    It's interesting to note how different compilers deal with the two chips -
    in particular, comparing gcc to commercial embedded compiler specialists
    like ImageCraft. On the avr, gcc has to go through a number of hoops
    (macros, attributes, etc.) to deal with flash-based data, while the msp430
    port works smoothly as flash data is as accessible as any other data.
    ImageCraft (and others) has a big advantage on the avr, in that they can
    "cheat" and use keywords to give a smoother coding style (in this case,
    "const" data is in flash).

    There are other aspects of the msp430 that make it more C-friendly than the
    avr - it has SP+index addressing modes, which make access to local
    non-register data far smoother than the AVR (in which it is a PITA -
    ImageCraft gets around it by dedicating a pointer register as a data stack
    pointer). It can also use any register as a pointer - the AVR has far too
    few pointer-capable registers.
     
    David Brown, Dec 22, 2003
    #19
  20. I think the weak dollar would make it cheaper in the states. The Philips
    distributor
    I use quoted me in the $7.50 (USD) range for the 2106 at one point. Plus
    the
    FAEs are drooling over this part, therefore I have found them quick to
    respond
    and unsually knowledgeable about it...

    Here's their page:
    http://www.futureelectronics.com

    --Keith
     
    Keith Brafford, Dec 27, 2003
    #20
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