resolve as

AVR Programming: Learning to Write Software for Hardware (Make: Technology on Your Time) (English Edition), p.47

while() loops are loops that continue running over and over as long as the condition inside the parentheses is true. And in C, 0 always resolves as false, and 1 always resolves as true.

while()ループは、カッコ内の条件が成立している限り(真である限り)繰り返され続けるループです。そしてCでは0は必ず偽であり1は必ず真です。