1.定时器原理

　　Timer，能产生特定的周期性中断。这个中断可以看作是操作系统心脏的脉动，用于实现时间的延时和确认超时。时钟节拍的频率越高，系统用于处理时钟中断的额外开销也越大。

　　W90P710 的24位 Timer 含有两个通道，分别是 Timer0 和 Timer1。每个通道有一个独立的时钟源，每隔一定时间，计数寄存器的值减 1，当计数寄存器的值达到零时，就会触发一次中断。设计通用软件可以在每个中断发生时加 1，达到计数的目的。

-timer principle



Timer, can produce specific periodic interrupt. The interrupt can be regarded as the operating system for the realization of the pulsating heart, delay and confirm the time timeout. Beat the clock frequency is high, the system for processing overhead clock interrupt more.



24 Timer W90P710 contain two channels, respectively is Timer0 and Timer1. Each channel has a separate clock source, at a certain time, count register value minus 1, when the count register value reaches zero, it will trigger an interrupt. Design can be in each interrupt occurs and 1 general software, to achieve the purpose of counting.