How to use correct clk in proteus?

[Ethan1]

I am simulating stm32f103c6 in proteus,I want to do timer2 interrupt ,I set pre = 7200-1,psc = 10000-1,so 1s to timer2 update interrupt.But time is not correct,it does not work.

I look up information,it is said I need to change stm32 clk to 8MHz,not 72MHz.How to do that?I read function systeminit,which is too complicated to find answer.

Also,can i use systick clk to make delay_us delay_ms in Proteus?I tried but it does not work

[Tesla DeLorean]

This is not a Proteus support forum.

Unfortunately "it does not work" is an unhelpful description.

What DOES it do? What SHOULD it do?

>>Time is not correct

How? Fast, Slow? What is it? What do you expect it to be?

The first should divide by 72,000,000 if you slow the clock to 8 MHz, this will take 9x longer

If SystemInit() does not initialize the HSE/PLL the processor will continue running at 8 MHz that the HSI clock starts the processor with.

You're not going to be able to 1us interrupts. SysTick is typically good for 1ms tick interrupts. It is a 24-bit down counter, not sure I'd use it to measure us, the wrapping math is a bit hairy. Figure out the PLL and SystemInit()first.

[Ethan1]

I use a led toggle to see how timer2 update interrupt work.

I. clk is 72HMz, I set ​time2 pre = 7200-1,psc = 10000-1，Proteus crystal is 8M。led does not change,does nothing,nothing happen

II. I change clk to 8MHz,set pre = 800-1 psc = 10000-1.Proteus crystal is 8M It should update interrupt timeout is 1s,but I use a watch to count,it is not 1s,it is about 2s.If I change 10000 to 5000, it is 1.21s.I was wondering if clk is 8MHz,I don`t know how to make stm32 work on 8MHz

#if defined (STM32F10X_LD_VL) || (defined STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)
/* #define SYSCLK_FREQ_HSE HSE_VALUE */
 #define SYSCLK_FREQ_24MHz 24000000
#else
#define SYSCLK_FREQ_HSE HSE_VALUE 
/* #define SYSCLK_FREQ_24MHz 24000000 */ 
/* #define SYSCLK_FREQ_36MHz 36000000 */
/* #define SYSCLK_FREQ_48MHz 48000000 */
/* #define SYSCLK_FREQ_56MHz 56000000 */
//#define SYSCLK_FREQ_72MHz 72000000
#endif
 
#ifdef SYSCLK_FREQ_HSE
 uint32_t SystemCoreClock = SYSCLK_FREQ_HSE; /*!< System Clock Frequency (Core Clock) */
#elif defined SYSCLK_FREQ_24MHz
 uint32_t SystemCoreClock = SYSCLK_FREQ_24MHz; /*!< System Clock Frequency (Core Clock) */
#elif defined SYSCLK_FREQ_36MHz
 uint32_t SystemCoreClock = SYSCLK_FREQ_36MHz; /*!< System Clock Frequency (Core Clock) */
#elif defined SYSCLK_FREQ_48MHz
 uint32_t SystemCoreClock = SYSCLK_FREQ_48MHz; /*!< System Clock Frequency (Core Clock) */
#elif defined SYSCLK_FREQ_56MHz
 uint32_t SystemCoreClock = SYSCLK_FREQ_56MHz; /*!< System Clock Frequency (Core Clock) */
#elif defined SYSCLK_FREQ_72MHz
 uint32_t SystemCoreClock = SYSCLK_FREQ_72MHz; /*!< System Clock Frequency (Core Clock) */
#else /*!< HSI Selected as System Clock source */
 uint32_t SystemCoreClock = HSI_VALUE; /*!< System Clock Frequency (Core Clock) */
#endif
 
 
 
static void SetSysClock(void)
{
#ifdef SYSCLK_FREQ_HSE
 SetSysClockToHSE();
#elif defined SYSCLK_FREQ_24MHz
 SetSysClockTo24();
#elif defined SYSCLK_FREQ_36MHz
 SetSysClockTo36();
#elif defined SYSCLK_FREQ_48MHz
 SetSysClockTo48();
#elif defined SYSCLK_FREQ_56MHz
 SetSysClockTo56(); 
#elif defined SYSCLK_FREQ_72MHz
 SetSysClockTo72();
#endif
 
 /* If none of the define above is enabled, the HSI is used as System clock
 source (default after reset) */ 
}

III. I use systick timer to make delay_us and delay_ms,it doesn`t delay

static u32 fac_ms=0;							//ms延时�?乘数
 
void delay_init(u8 SYSCLK)
{
#if SYSTEM_SUPPORT_OS 						//如果需�?支�?OS.
	u32 reload;
#endif
		SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK);	//选择外部时钟 HCLK/8
 
// HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);//SysTick频率为HCLK
	fac_us=SYSCLK;						//�?论是�?�使用OS,fac_us都需�?使用
#if SYSTEM_SUPPORT_OS 						//如果需�?支�?OS.
	reload=SYSCLK;					 //�?秒钟的计数次数 �?��?为K	 
	reload*=1000000/delay_ostickspersec;	//根�?�delay_ostickspersec设定溢出时间
											//reload为24�?寄存器,最大值:16777216,在72M下,约�?�0.233s左�?�	
	fac_ms=1000/delay_ostickspersec;		//代表OS�?�以延时的最少�?��?	 
	SysTick->CTRL|=SysTick_CTRL_TICKINT_Msk;//开�?�SYSTICK中断
	SysTick->LOAD=reload; 					//�?1/OS_TICKS_PER_SEC秒中断一次	
	SysTick->CTRL|=SysTick_CTRL_ENABLE_Msk; //开�?�SYSTICK
#else
#endif
}								 
 
void delay_ms(u16 nms)
{	 		 	 
	u32 temp;		 
	SysTick->LOAD=(u32)nms*fac_ms;				//时间加载(SysTick->LOAD为24bit)
	SysTick->VAL =0x00;							//清空计数器
	SysTick->CTRL|=SysTick_CTRL_ENABLE_Msk ;	//开始倒数 
	do
	{
		temp=SysTick->CTRL;
	}while((temp&0x01)&&!(temp&(1<<16)));		//等待时间到达 
	SysTick->CTRL&=~SysTick_CTRL_ENABLE_Msk;	//关闭计数器
	SysTick->VAL =0X00; 					//清空计数器	 	 
}