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microcontroller with updateable program memory while running?

Discussion in 'Electronic Design' started by Frank Buss, Sep 20, 2003.

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  1. Frank Buss

    Frank Buss Guest

    I'm searching a microcontroller, which can re-propram itself from within
    the microcontroller. Something like the DS5000
    (, but without the 10-
    year limit for loosing the content of the memory.

    The following architecture would be great: Some flash memory integrated on
    the chip and some RAM. On reset the content of the flash memory will be
    copied to the RAM, which then can be executed. Another thing I wish: no
    difference between data and program memory, so the program can read and
    write itself. And the program should be able to change the flash memory for
    firmware updates. And all this in one chip :)
  2. The modern microcontrollers are able to do that.
    The AVR Mega Series, perhaps some newer PIC, the TI
    controllers, and so on. Have a look at the respective
    manufacturers pages.

  3. Frank Buss

    Frank Buss Guest

    Thanks for the fast response. The ATmega32 looks very good. It doesn't copy
    the flash memory to RAM, but executes the program in the flash memory. And
    the flash memory can be updated from the program running on the chip, even
    the memory containing the update program.

    Some more nice features, which I need in my application: USART and 3 V
    power supply (the L-type). And the 32 IO ports, 10 bit ADC, 32 kb flash,
    1024 bytes EEPROM, 2 kb SRAM and 32 general purpose registers are more than
    enough for my application. The price is fair (e.g. 12.75 euro at ).

    At and I didn't found anything
    like this.

    These have up to 64K words flash with >40 years retention and self
    reprogrammable, 4K internal SRAM and able to address external SRAM, 5
    timers + watch dog, 16 10-bit ADC, 68 IO pins, 10 MIPS.

  5. Frank Buss

    Frank Buss Guest

    Thanks, the 18F252 looks nice. Compared to the Amtel32 it has not so much
    flash and SRAM, but 16 kb flash and 1.5 kb RAM is fine for my

    and costs 8,60 euro, only, so you get three 18F252 for the price of two
    ATmega32 :)

    I think I'll use the PIC, because I've already good experience with the
    16F84 and I can use my PICSTART for programming it, I hope. But in the
    end perhaps someone knows a chip from TI for comparing to the other
  6. Is that incl or excl VAT ?
    The 18F252 costs 7,65 EUR excl VAT here :
    Note that the programming algorithms are very different between the
    *OLD* 16F84 and the newer PICs. You realy has to check your programmer.
    B.t.w, I use the programmer that you can find on the same site as the
    price figure above : "". Works
    just great.
  7. Frank Buss

    Frank Buss Guest

    It's incl VAT (7,41 euro excl VAT), type "18f252" at "Artikelsuche" at
    I've updated it some years ago. Ok, now I've reinstalled the last
    downloaded MPLAB version 5.4, which worked with my update and it supports
    the 18F252. Perhaps I'll update to MPLAB 6 and the new firmware, when
    ordering the chip and a 17C44 for the programmer update.
    Looks a bit like homebrew electronic. With PICSTART you can program
    nearly all PICs (not the one in TQFP package without adapters), you have
    an IDE with an integrated emulator for testing parts of the program on
    the PC with simulated inputs and there are updates from the producer, if
    new chips are developed.
  8. I've tinkered around with the 16F84(a) and the 16F628, but haven't used
    the 18F series yet. I've been going thru the data sheet for the 18Fxx2
    line and it's definitely a bit different and will take some getting used
    to. I mean that in a good way though. ;-) Code paging is no longer a
    hassle and the RAM banking is a bit more user friendly for newbies.
    They seem like really nice chips with the bigger stack and extra
    instructions, at least more friendly for C compilers than the 16F's.
    Enjoy and good luck.

  9. Alex Gibson

    Alex Gibson Guest

    18f's are much nicer than the 16f's.
    a few with a bit more flash(>64kB) would be nice
    and I'd wish they would hurry up and release
    the usb versions they promoted for a very short period
    before completely removing all the details.

    no free compiler yet for the 18fxxx's
    supposedly there are a few people working on a gcc port,
    I haven't been able to track them down yet.

    For the avr's there is a port of gcc ,
    or see

    I believe there is also a port of gcc for the ti msp430's .

  10. onestone

    onestone Guest

    Then have a look at ti are wierd, they class the MSP430
    micro as an analog part, fooling most frirst time lookers.

    If you like the ATMega then you'll love the MSP430F149/169.

    8MHz clock
    60K flash
    2K sram
    2 * Uarts
    2 x SCI
    up to 10 PWM/capture compare channels
    8 x 12 bit A/D at 500ksps
    hardware multiplier/MAC in the 14x series
    very low current
    4 power saving modes, dual cystals
    built in DCO
    About US$7-8

  11. Looks a bit like homebrew electronic.

    It is home-developed, because my company is at my home. But it is not
    actually produced at home, there are much cheaper places to have that
    done :)
    The IDE has nothing to do with the PS programmer, except that using
    the programmer from the IDE is easy. You can develop your code in
    MPLAB and then use just about any progger (including Wisp628, of
    course) to do the progging.

    One limitation of my Wisp628: it will not prog any non-flash PICs. But
    the chance that you would want to use one of the old EPROM models is
    very small.
    No. The 17C44 using in the PS+ is full, the latest flash chips are not
    supported by the PS+. BTW the 16F628 in the Wisp628 is full too, but I
    still manage to support all flash chips that I get my hands on because
    the chip does not contain specific code for each target. And there is
    the 16F648A if I ever need more room.

    BTW if you want to start with PICs you might want to read

    Wouter van Ooijen

    -- ------------------------------------
    PICmicro chips, programmers, consulting
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