自学教程：C++ systick_counter_enable函数代码示例

void systick_setup(void){    systick_set_reload(rcc_ahb_frequency / SYSTICK_HZ);    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);    systick_counter_enable();    systick_interrupt_enable();}

/* * Initialise the Cortex-M3 SysTick timer */void timer_init(void) {	system_millis = 0;	/*	 * MCU clock (120 MHz) as source	 *	 *     (120 MHz / 8) = 15 clock pulses	 *	 */	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);	STK_CVR = 0;	/*	 * 1 tick = 1 ms @ 120 MHz	 *	 *     (15 clock pulses * 1000 ms) = 15000 clock pulses	 *	 * Send an interrupt every (N - 1) clock pulses	 */	systick_set_reload(14999);	/* SysTick as interrupt */	systick_interrupt_enable();	systick_counter_enable();}

void systick_init(void){	systick_ms = 0;	systick_set_frequency(1000, rcc_ppre2_frequency*2);	systick_interrupt_enable();	systick_counter_enable();}

void tick_init(void){  uint32_t systick_reload_val;  g_ulSysTickCount = 0;  /* Disable IRQ globally */  asm volatile ("cpsid i");  /* Set processor Clock as Source Clock */  systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);  systick_set_reload(rcc_ahb_frequency / 1000);  systick_interrupt_enable();  /* Start counting. */  systick_counter_enable();  /* Set SysTick Priority to maximum */  nvic_set_priority(NVIC_SYSTICK_IRQ, 255);  /* Enable IRQ globally */  asm volatile ("cpsie i");  scs_dwt_cycle_counter_enabled();}

int main(void){	/* Check the force bootloader pin*/	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);	if(!gpio_get(GPIOA, GPIO0))		dfu_jump_app_if_valid();	dfu_protect_enable();	/* Set up clock*/	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);	systick_set_reload(2100000);	systick_interrupt_enable();	systick_counter_enable();	/* Handle LED */	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPDEN);	gpio_clear(GPIOA, GPIO4);	gpio_mode_setup(GPIOA, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE,			GPIO4);	/* Set up USB*/	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);	rcc_peripheral_enable_clock(&RCC_AHB2ENR, RCC_AHB2ENR_OTGFSEN);	/* Set up USB Pins and alternate function*/	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE,		GPIO9 | GPIO10 | GPIO11 | GPIO12);	gpio_set_af(GPIOA, GPIO_AF10, GPIO9 | GPIO10| GPIO11 | GPIO12);	dfu_init(&stm32f107_usb_driver);	dfu_main();}

void time_init() {  systick_set_reload(0xffffff);  systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB);  rollovers = 0;  systick_interrupt_enable();  systick_counter_enable();}

void init_systick(void){	systick_set_frequency(HZ, 72000000);	systick_interrupt_enable();	systick_counter_enable();}

int main(void){	rcc_clock_setup_in_hse_8mhz_out_72mhz();	gpio_setup();	gpio_clear(GPIOA, GPIO7);	/* LED1 on */	gpio_set(GPIOA, GPIO6);		/* LED2 off */	temp32 = 0;	/* 72MHz / 8 => 9000000 counts per second */	systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);	/* 9000000/9000 = 1000 overflows per second - every 1ms one interrupt */	/* SysTick interrupt every N clock pulses: set reload to N-1 */	systick_set_reload(8999);	systick_interrupt_enable();	/* Start counting. */	systick_counter_enable();	while (1); /* Halt. */	return 0;}

void systick_setup(void){    uint32_t systick_reload_val;    g_ulSysTickCount = 0;    /* Disable IRQ globally */    __asm__("cpsid i");    /* Set processor Clock as Source Clock */    systick_set_clocksource(STK_CTRL_CLKSOURCE);    /* Get SysTick calibration value to obtain by default 1 tick = 10ms */    systick_reload_val = systick_get_calib();    /*     * Calibration seems wrong on LPC43xx(TBC) for default Freq it assume System Clock is 12MHz but it is 12*17=204MHz     * Fix the Calibration value bu multiplication by 17     */    systick_reload_val = (systick_reload_val*17);    /* To obtain 1ms per tick just divide by 10 the 10ms base tick and set the reload */    systick_reload_val = systick_reload_val/10;    systick_set_reload(systick_reload_val);    systick_interrupt_enable();    /* Start counting. */    systick_counter_enable();    /* Set SysTick Priority to maximum */    nvic_set_priority(NVIC_SYSTICK_IRQ, 0xFF);    /* Enable IRQ globally */    __asm__("cpsie i");}

int main(void){	/* Check the force bootloader pin*/	rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);	if(gpio_get(GPIOB, GPIO12))		dfu_jump_app_if_valid();	dfu_protect_enable();	rcc_clock_setup_in_hse_8mhz_out_72mhz();	systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);	systick_set_reload(900000);	rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);        rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USBEN);	gpio_set_mode(GPIOA, GPIO_MODE_INPUT, 0, GPIO8);	systick_interrupt_enable();	systick_counter_enable();	gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,			GPIO_CNF_OUTPUT_PUSHPULL, GPIO11);	gpio_set_mode(GPIOB, GPIO_MODE_INPUT,			GPIO_CNF_INPUT_FLOAT, GPIO2 | GPIO10);	dfu_init(&stm32f103_usb_driver);	gpio_set(GPIOA, GPIO8);	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_2_MHZ,			GPIO_CNF_OUTPUT_PUSHPULL, GPIO8);	dfu_main();}

void time_init(void) {  system_ms = 0;  systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);  STK_CVR = 0;  systick_set_reload(32000000/1000 -1);  systick_counter_enable();  systick_interrupt_enable();}

void systick_setup(void){	systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8); // 24meg / 8 = 3Mhz	// one interrupt per ms..	systick_set_reload(3000);	systick_interrupt_enable();	systick_counter_enable();}

/* Implementing a usleep alternative*/void _delay_us(u32 delay_us){    tick_us = 0;    desired_us = delay_us;    systick_counter_enable();    while( tick_us < desired_us);// This provides the busy-wait    systick_counter_disable();// Kill the interrupt if not using it.  The ISR just slows down the uC}

void stick_init(int32_t hz){	ticks = 0;	systick_set_frequency(hz, rcc_ppre2_frequency*2);	systick_interrupt_enable();	systick_counter_enable();}

void SetupSystick(void){	// Clock rate / 1000 = 168000 for one ms	systick_set_reload(168000);	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);	systick_counter_enable();	systick_interrupt_enable();}

int platform_init(void){	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);	/* Enable peripherals */	rcc_peripheral_enable_clock(&RCC_AHB2ENR, RCC_AHB2ENR_OTGFSEN);	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPBEN);	rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPCEN);        /* Fix all flaoting pins*/	gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_PULLDOWN,                        0x1ff);	gpio_mode_setup(GPIOB, GPIO_MODE_INPUT, GPIO_PUPD_PULLDOWN,                        0xffe2);	gpio_mode_setup(GPIOC, GPIO_MODE_INPUT, GPIO_PUPD_PULLDOWN,                        0xf3ff);	/* Set up USB Pins and alternate function*/	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE,		GPIO9 | GPIO10| GPIO11 | GPIO12);	gpio_set_af(GPIOA, GPIO_AF10, GPIO9 | GPIO10| GPIO11 | GPIO12);        /* Set TMS/TCK/TDI to high speed*/        GPIOA_OSPEEDR &=~0xfc00;        GPIOA_OSPEEDR |= 0xa800;	gpio_mode_setup(JTAG_PORT, GPIO_MODE_OUTPUT,			GPIO_PUPD_NONE,			TMS_PIN | TCK_PIN | TDI_PIN);	gpio_mode_setup(TDO_PORT, GPIO_MODE_INPUT,			GPIO_PUPD_NONE,			TDO_PIN | TRST_PIN);	gpio_mode_setup(LED_PORT, GPIO_MODE_OUTPUT,			GPIO_PUPD_NONE,			LED_UART );	/* Setup heartbeat timer */	systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);	systick_set_reload(168000000/(10*8));	/* Interrupt us at 10 Hz */	SCB_SHPR(11) &= ~((15 << 4) & 0xff);	SCB_SHPR(11) |= ((14 << 4) & 0xff);	systick_interrupt_enable();	systick_counter_enable();	usbuart_init();	SCB_VTOR = 0x10000;	// Relocate interrupt vector table here	cdcacm_init();	jtag_scan(NULL);	return 0;}

void time_init() {  { CriticalSection cs;    systick_set_reload(0xffffff);    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);    rollovers = 0;    systick_interrupt_enable();    systick_counter_enable();  }}

/* * systick_setup(void) * * This function sets up the 1khz "system tick" count. The SYSTICK counter is a * standard feature of the Cortex-M series. */static void systick_setup(void){	/* clock rate / 1000 to get 1mS interrupt rate */	systick_set_reload(168000);	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);	systick_counter_enable();	/* this done last */	systick_interrupt_enable();}

/* Set up timer to fire freq times per second */static void systick_setup(int freq){	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);	/* clear counter so it starts right away */	STK_CVR = 0;	systick_set_reload(32000000 / freq);	systick_counter_enable();	systick_interrupt_enable();}

static void systick_setup(void) {    /* 72 MHz with DIV 8 -> systick clock source of 9MHz */    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);    /* Systick interrupt period 1ms -> 9MHz / 1kHz = 9000 */    systick_set_reload(9000 - 1);    systick_interrupt_enable();    systick_counter_enable();}

/** * initialise and start SysTick counter. This will trigger the * sys_tick_handler() periodically once interrupts have been enabled * by archFirstThreadRestore() */static void systick_setup(void){    //systick_set_frequency(SYSTEM_TICKS_PER_SEC, 72000000); OLD :: MOD    systick_set_frequency(SYSTEM_TICKS_PER_SEC, 24000000);    systick_interrupt_enable();    systick_counter_enable();}

void time_delay_ms(unsigned int delay) {  uint32_t wake = system_ms + delay;  uint32_t cnt;  do {    systick_counter_disable();    cnt = system_ms;    systick_counter_enable();  }  while (wake > cnt);}

void clock_setup(void){	rcc_clock_setup_hse_3v3(&rcc_hse_8mhz_3v3[RCC_CLOCK_3V3_168MHZ]);	/* set up the SysTick function (1mS interrupts) */	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);	STK_CVR = 0;	systick_set_reload(rcc_ahb_frequency / 1000);	systick_counter_enable();	systick_interrupt_enable();}

void setup_clock(void){    /* Setup clock source @ 32MHz */    rcc_clock_setup_pll(&rcc_clock_config[1]);    /* Setup sysclock to trigger every 1ms */    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);    systick_set_reload(3999);    systick_interrupt_enable();    systick_counter_enable();}

/* * Set up timer to fire every x milliseconds * This is a unusual usage of systick, be very careful with the 24bit range * of the systick counter!  You can range from 1 to 2796ms with this. */static void systick_setup(int xms){    /* div8 per ST, stays compatible with M3/M4 parts, well done ST */    systick_set_clocksource(STK_CSR_CLKSOURCE_EXT);    /* clear counter so it starts right away */    STK_CVR = 0;    systick_set_reload(rcc_ahb_frequency / 8 / 1000 * xms);    systick_counter_enable();    systick_interrupt_enable();}

static void config_clocks(void){	rcc_clock_setup_in_hse_8mhz_out_24mhz();	/* Set systick timer to strike every 1ms (1kHz),	 * enable its interrupt and start it. */	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);	systick_set_reload(rcc_apb2_frequency / 8 / 1000 - 1);	systick_interrupt_enable();	systick_counter_enable();}

/* * clock_setup(void) * * This function sets up both the base board clock rate * and a 1khz "system tick" count. The SYSTICK counter is * a standard feature of the Cortex-M series. */void clock_setup(void){	/* Base board frequency, set to 168Mhz */	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);	/* clock rate / 168000 to get 1mS interrupt rate */	systick_set_reload(168000);	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);	systick_counter_enable();	/* this done last */	systick_interrupt_enable();}

void systick_setup(void){	/* 72MHz / 8 => 9000000 counts per second */	systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);	/* 9000000/9000 = 1000 overflows per second - every 1ms one interrupt */	systick_set_reload(9000);	systick_interrupt_enable();	/* Start counting. */	systick_counter_enable();}

static void systick_setup(void) {    /* 72MHz / 8 => 9000000 counts per second */    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);    /* 9000000/9000 = 1000 overflows per second - every 1ms one interrupt */    /* SysTick interrupt every N clock pulses: set reload to N-1 */    systick_set_reload(8999);    systick_interrupt_enable();    /* Start counting */    systick_counter_enable();}