读程序: include #include"systick. h" void Systick config(unsigned int nms I Sys TICK->CTRL&=OXFFFFFFFB Sys Tick->LOAD=(unsigned long)nms'10 Sys TICK->VAL =0X00 Systick->CTRLF(3ul<<0 GPIOD initial () Sys Tick config(l ) while(1) l void sys tick Handler( void) GPIOAD->ODR(Oxfful Sys Tick->CTRL&--(Iuk<<16): 1)分析程序执行机制 2)画程序流程图 3)概括程序功能