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MIOS V1.8


TK.

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The public release of MIOS V1.8 is finally available at the http://www.ucapps.de/mios_download.html page

Changes:

  • the interrupt handler now also saves FSR0L and FSR0H.
    This allows the use of C programs compiled with sdcc

  • a wrapper for the SDCC compiler is now available in a seperate package.
    More informations can be found under http://www.ucapps.de/mios_c.html

  • the motorfader driver has been overworked. The new concept works with a "dynamic deadband" and a definable PWM which will be used once the fader reaches the target position.
    The details are described at http://www.ucapps.de/mbhp_mf.html

  • on a MIOS up- or download, the BankStick number is now selected with an address extension, which is part of the SysEx command

  • the "Brown Out Reset" (BOR) settings in the configuration sector are changed automatically when MIOS detects unproper settings - the appr. cell in this sector will be overwritten and the device will be reset.
    New Setting: Brown Out Reset at 4.5V
    This ensures that the PIC won't access devices during power-off which cannot operate at voltages < 4.5V (e.g. the BankStick, which could get an unintended write command)

  • support for PIC18F4620 (64k flash device) --- in the source code only (no precompiled binary available)
    Unfortunately this derivative is currently not qualified for MIOS due to a silicon bug in the EUSART peripheral (rev3)



    Some words to the PIC18F4620: Synapsys informed me about this new derivative some days ago (thanks Bob!) - it is a great replacement for the PIC18F452, because it is pin compatible and provides 64k flash (two times more than the 18F452), 3966 bytes RAM (> two times more than the 18F452), 4k EEPROM (four times more than the 18F452)
    There is already an updated Bootstrap Loader in the CVS which is located to 0xfc00. Also the mk_syx script has been updated in order to support the upper memory area (thats the reason for the new "address extension" in the SysEx upload/download command).

    So: this could be the future chip for the MBHP platform, because the price isn't much higher, but the benefit is -- let's say --- unbelievable! :-) It opens a lot of new possibilities for applications which ran out of memory, especially for MIDIbox SID, FM and especially SEQ

    BUT: the current silicon release contains the same EUSART bug which I found on the PIC18F4550 (I checked this with a rev3 sample) - It makes the chip unusable for high-performance MIDI applications! Therefore please DON'T BUY THIS CHIP yet, until Microchip has regognized that this is a serious problem, and released a new silicon version. This could take some weeks, some months, ... nobody knows.

    There is a workaround, but I must say that this won't be supported from my side due to development effort and performance drawbacks: by using an external USART, which is connected via SPI or IIC it should be possible to realize reliable MIDI transfers. But this can only be a "tinkering solution", it requires changes in MIOS and increases the CPU load

    I prefer to wait for a full functional silicon. Once available, just replace the PIC18F452 and be happy about a lot of new possibilities :)

    -----

    Following applications have been updated:

    • mf_calibration: due to new MF driver
    • mf_direct_control: due to new MF driver
    • midibox_hn: due to new MF driver
    • midibox_lc: due to new MF driver, got also some minor bugfixes
    • midibox_mm: due to new MF driver, has been completely rewritten in C
    • skeleton_v1_8: due to new MIOS release
    • sdcc_skeleton_v1_0: first C wrapper release


    • Have fun!

      Best Regards, Thorsten.

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