基于IAR的ATtiny13A的程序，主要实现方波的输出以及如何运用好AVR的头文件，非常适合初学者。经过测试，可以直接烧录。-IAR' s ATtiny13A based program, the main achievement of the square wave output and how to make good use of the AVR header files, ideal for beginners. After testing, you can burn direc