Situation: You want to include a timer interrupt service routine in an assembly language program for an AVR-based Arduino. The program will be written, assembled and uploaded using the Arduino IDE.

This project is a working example how to get an I2S DAC working on a Arduino. This sketch uses port manipulation instead of the arduino's library function digitalRead and digitalWrite, because port ...

but instead I found such an thorough and well thought-through answer on StackExchange that I thought I had to point it out. So, t0 the question: What is AVR Arduino interrupt latency? And how can it ...