在S3C44B0上实现的键盘和LED驱动程序，其关键是使用了系统定时器来提高效率。此代码依赖于硬件的GPIO接口，但只需按照实际稍微改动即可。-S3C44B0 in achieving the keyboard and LED driver, The key is to use a timer system to improve efficiency. This code depends on the hardware GPIO interface, but only in accordance