AVReAl update — 1.28r14

avreal v1.28r14 (Mon 2013-08-05) has been released.

  • Error in ATmega128rfr2, ATmega256rfr2 signatures — fixed;
  • ATmega32HVE, ATmega64HVE added.

AVReAl update — 1.28r13

avreal v1.28r13 (Sun 2013-06-02) has been released.

bug in resync (MPSSE)

Bug was found in SCK-pulse synchronisation in following conditions:

  • firmware sets high level on SCK pin;
  • an MPSSE-based adapter is used (FT2232, FT4232, FT232H).

Microcontroller can be programmed again via USB-based adapter after erasing via LPT-based adapter.

In my case the bug appears with AT90S8515 but not reproduced for ATmega168.

Bugfix will be published as soon as possible.

The bug has been fixed in version 1.28r13.

AVReAl update — 1.28r9

avreal v1.28r9 (Tue 2011-12-20) has been released.

  • FT232H MPSSE mode support added.
  • Delays processing in Windows version changed: lower CPU load for -k/-K switches.
  • Resynchronisation method changed for all microcontrollers.
    Resync process started with one attempt of RESET pulse method then continued with SCK pulse method.
    More about synchronisation.

ISP-programmer to AVR synchronisation

AVR ISP-programming starts with RESET activation following by transmitting of programming enable instruction. Entry sequence requirement is that SCK must be set to ‘0’ during RESET activation. Otherwise SCK falling edge causes unintended programming hardware state change.

AVR programming waveforms

The falling edge distorts 4-byte programming instruction. The microcontroller does not recognise it and does not enter programming mode. There is no sense to send programming entry instruction again because byte-level command’s phase is shifted by one SCK period. The last SCK pulse of previous instruction will act as extra pulse for subsequent command.

Synchronisation can also be corrupted during programming process. Read more in publication about AVReAl “synchronisation lost” message.

Atmel datasheets describe two methods for synchronisation recovery.

»»» Read more about resynchronisation[/lаng_en]

synchronisation vs synchronization

I have accidentally noticed that in avreal and in site texts and as a tag name I use british writing “synchronisation”. Like Molière’s character Jourdain I didn’t know that I used british writing. It is strange because american “synchronization” is used in Atmel datasheet which I quoted in “avreal synchronisation lost” post.

AVReAl update — 1.28r5

avreal v1.28r5 (Tue 2010-10-12) has been released.

  • Synchronisation lost after verification for FT2232/FT4232-based adapters — fixed.
  • ATmega128RFA1 added

AVReAl update — 1.28r4

avreal v1.28r4 (Tue 2010-09-07) has been released.

The bug has been fixed in version 1.28r5.

bug in avreal 1.28r2 and 1.28r3

A strange bug was found in avreal 1.28r2 and 1.28r3. At the coincidence of conditions

  • An FT2232/FT4232-based adapter is used
  • There are some data for top two flash bytes — either data from hex-file or erase counter
  • flash and fuses are used in one avreal call
  • -v verification switch is used

for some microcontroller types avreal fails with “synchronosation lost” error after the first verification.

Continue reading ‘bug in avreal 1.28r2 and 1.28r3’ »

avreal synchronisation lost

Everything you wanted to know about,
but were afraid to ask.

As can be found in site log phrase “synchronisation lost” is one of most popular in site search, but no one asks the question in comments.

“synchronisation lost” message means programmer-to-microcontroller communication fault. SPI interconnection between programming adapter and microcontroller works in the same manner as between two microcontrollers.


Continue reading ‘avreal synchronisation lost’ »

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