https://www.baszerr.eu/ Wed, 06 May 2026 11:15:24 +0000 FeedCreator 1.8 https://www.baszerr.eu/lib/exe/fetch.php?media=wiki:dokuwiki.svg https://www.baszerr.eu/ https://www.baszerr.eu/doku.php?id=blog:2014:05:27:atmega64_a_compatibility_bit <h1 class="sectionedit1" id="atmega64_a_compatibility_bit">2014-05-27 - ATmega64(A) compatibility bit</h1> <div class="level1"> <p> recently got surprised by <a href="http://www.atmel.com/Images/Atmel-8160-8-bit-AVR-Microcontroller-ATmega64A-datasheet.pdf" class="urlextern" title="http://www.atmel.com/Images/Atmel-8160-8-bit-AVR-Microcontroller-ATmega64A-datasheet.pdf" rel="ugc nofollow">ATmega64A</a> <a href="https://www.baszerr.eu/doku.php?id=blog:2014:05:02:spi_atmega64_a" class="wikilink1" title="blog:2014:05:02:spi_atmega64_a" data-wiki-id="blog:2014:05:02:spi_atmega64_a">once again</a>. this time LCD display did not worked well. i used well tested, open source <a href="http://homepage.hispeed.ch/peterfleury/avr-software.html" class="urlextern" title="http://homepage.hispeed.ch/peterfleury/avr-software.html" rel="ugc nofollow">LCD-library</a> for HD44870-based displays. it did not worked. i&#039;ve used <a href="https://www.saleae.com" class="urlextern" title="https://www.saleae.com" rel="ugc nofollow">logic state analyzer</a> (which is awesome, btw!) and noticed that several control pins appear to be dead, even though µC was up and running (other pins did output proper signals). </p> <p> the answer has been found in sections 14.3.6 and 14.3.7 of ATmega64A&#039;s datasheet: ports F and G behave very differently (one is an input-only while the other is alternative function only), when used in “ATmega103 compatibility mode”. yes – you guessed – compatibility mode was turned on by default. i wonder how many more subtleties are waiting out there… </p> </div> anonymous@undisclosed.example.com (Anonymous) Tue, 15 Jun 2021 20:08:55 +0000