avr-libc 當中有個 <util/atomic.h>，第一個反應是明明 avr 都是單核才對，為什麼還需要 atomic，所以下意識看了一下說明。 The macros in this header file deal with code blocks that are guaranteed to be excuted Atomically or Non-Atmomically. The term "Atomic" in this context refers to the…