add uiflow timer usage

docs/en/uiflow/introduction.md

@@ -187,4 +187,32 @@ Get current system run time.
 
 >Add the Wait Block to the program that needs to be delayed and set the time. When the program executes to it, it will play a delay.
 
-><img src="/image/Program_structure/Wait_user.gif" width="50%">
+><img src="/image/Program_structure/Wait_user.gif" width="50%">
+
+
+# Timer
+_____________________________
+
+#### Function Description
+
+>Timer is a timer function that can be run into the program block periodically.
+
+><img src="/image/Program_structure/Timer.png" width="20%">
+
+* __Timer callback__
+Timer callback function, executed regularly
+
+* __Start period ms mode__
+The timer is started to run at the specified time interval. There are two setting modes, One_shot is executed once, and periodic is executed periodically.
+
+* __Set period ms mode__
+Modify the time parameter and running mode of the specified timer.
+
+* __Stop__
+Stop timer.
+
+#### Usage
+
+>Add two timers, count separately according to time parameters.
+
+><img src="/image/Program_structure/Timer_user.gif" width="50%">

docs/zh_CN/uiflow/introduction.md

@@ -181,4 +181,34 @@ _____________________________
 
 >将Wait Block添加到需要延时的程序之间并设定时间，在程序执行到它时，就会发挥延时作用 
 
-><img src="/image/Program_structure/Wait_user.gif" width="50%">
+><img src="/image/Program_structure/Wait_user.gif" width="50%">
+
+
+# Timer
+_____________________________
+
+#### 功能说明
+
+>Timer是一个定时器函数，可以定期进入程序块运行
+
+><img src="/image/Program_structure/Timer.png" width="20%">
+
+* __Timer callback__
+定时器回调函数，定期执行
+
+* __Start period ms mode__
+开启定时器以指定的时间间隔运行，设置模式有两种，One_shot为执行一次，periodic为周期执行
+
+* __Set period ms mode__
+修改指定定时器的时间参数和运行模式
+
+* __Stop__
+终止定时器
+
+#### 使用方法
+
+>添加两个定时器，依据时间参数分别计数
+
+><img src="/image/Program_structure/Timer_user.gif" width="50%">
+
+