Thanks for the rsponse. Merry Christmad,
Jan Verstuurd vanaf mijn iPad > Op 25 dec. 2018 om 10:36 heeft Matthias Trute <mtr...@web.de> het volgende > geschreven: > > Am Montag, den 24.12.2018, 17:51 +0000 schrieb Jan Kromhout: >> Hello, >> >> I wont to write my own routine in assembler as a learning goal. >> Have looked into a lot of asm routines, but can’t figure out how to >> add two doubles into R16 to R23 >> and after the calculation put R16 to R19 back to the stack. >> >> Can I use R16 to R19 freely for my own use, or should I take another >> set. >> >> The calculation between is no problem. >> >> Please can someone help me out with this, >> and any help is appriciated! > > The registers that are free to use in own assembly words > are documented here: > http://amforth.sourceforge.net/TG/AVR8.html#register-mapping > > The mapping between the temp-Names and the actual registers > can be found at avr8/macros.asm. > > If you want to go deep into the assembler programming, esp. > within amforth, I'd strongly recommend, that you study the > code very carefully. It contains optimizations and macros > that are not trivially to understand. Adding two double > numbers (that is 2x4 avr registers) is more on the > trivial side however. look at words/d-plus.asm. > > Matthias > > > > _______________________________________________ > Amforth-devel mailing list for http://amforth.sf.net/ > Amforth-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/amforth-devel _______________________________________________ Amforth-devel mailing list for http://amforth.sf.net/ Amforth-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/amforth-devel
