STM32 using TIMX_CH1 as tx1f_ed counter clock

Environment: IAR ARM 5.3

Stm32f103vbt6

Use the pa.8 external input 10Mhz square wave. Data 4 can be obtained from Systick interrupts.

4x5000 (prescaler value) x1000 (tick interrupt Time) =20mhz

Belonging to the bilateral edge detection, a pa.8 pulse has 2 edges, so the clock doubles.

Due to the use of ti1f_ed it is structured as follows:

voidRcc_configuration (void ){  /*Setup STM32 System (Clock, PLL and Flash configuration)*/Systeminit (); /*Enable Gpioa, GPIOC and USART1 clock*/Rcc_apb2periphclockcmd (Rcc_apb2periph_gpioa| RCC_APB2PERIPH_GPIOC |rcc_apb2periph_tim1, ENABLE);} Gpio_initstructure.gpio_pin=Gpio_pin_8; Gpio_initstructure.gpio_mode=gpio_mode_in_floating; Gpio_initstructure.gpio_speed=Gpio_speed_50mhz; Gpio_init (Gpioa,&gpio_initstructure);voidTim1_init (void) {tim_timebaseinittypedef tim_timebasestructure; Tim_timebasestructure.tim_period=65535; Tim_timebasestructure.tim_prescaler= the; Tim_timebasestructure.tim_clockdivision=Tim_ckd_div1; Tim_timebasestructure.tim_countermode=tim_countermode_up; Tim_timebaseinit (TIM1,&tim_timebasestructure); Tim_tixexternalclockconfig (TIM1, tim_tixexternalclk1source_ti1ed, tim_icpolarity_rising,0 );  Tim_cmd (TIM1, ENABLE); }intMainvoid) {rcc_configuration ();  Gpio_config ();  Tim1_init (); /*Setup SysTick Timer for 1 msec interrupts*/  if(Systick_config (Systemfrequency/ + ) )  {    /*Capture Error*/     while(1 )      ; }     while(1 )  {  }}voidSystick_handler (void ){  StaticU32 i =0; if(i = =0) {i=1; Gusdata=0; Tim_setcounter (TIM1,0 ); }  Else{i=0; Gusdata=Tim_getcounter (TIM1); }  }

STM32 using TIMX_CH1 as tx1f_ed counter clock