【CW32L052 Review】 Sysclk Delay Test

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【CW32L052 Review】 Sysclk Delay Test [Copy link]

 

In this article, we will learn how to configure and use the sysclk clock of the CW32L052 chip.

1. Clock Block Diagram

The maximum clock that the chip can operate at is 48MHz. Here, the internal 48MHz HSI clock is used to configure sysclk.

2. Procedure

2.1 Clock Configuration

The clock configuration is a bit strange. If you directly enable HSI at 48MHz, the program will not start. If the clock is switched to HSE or LSI and then back to HSI, it can start and run normally.

void rcc_config(void)
{
	uint8_t res = 0U;
	RCC_AHBPeriphClk_Enable(RCC_AHB_PERIPH_FLASH, ENABLE);
	RCC_LSI_Enable( );                                                   //开启外部高速时钟LSI
	res = RCC_SysClk_Switch( RCC_SYSCLKSRC_LSI );                        //切换系统时钟到LSI
	if( res == 0x00 )                                                    //系统时钟切换成功
	{
			RCC_HSI_Disable();                                               //切换时钟到PLL后关闭源时钟HSI
			FirmwareDelay( 400 );   //about 100mS
	}
	
	RCC_HSI_Enable( RCC_HSIOSC_DIV1 );                                   //开启内部高速时钟HSI = HSIOSC / 2
	FLASH_SetLatency(FLASH_Latency_3); 
	res = RCC_SysClk_Switch( RCC_SYSCLKSRC_HSI );                        //切换系统时钟到HSI
	if( res == 0x00 )                                                    //系统时钟切换成功
	{
			RCC_LSI_Disable();                                               //切换时钟到HSI后关闭LSI时钟
			FirmwareDelay( 275000 );  //about 100mS
	}
	
	RCC_HCLKPRS_Config(RCC_HCLK_DIV1);
	
	RCC_HCLK_OUT();                           //通过PA04观察HCLK频率
}

2.2 Main Program

Configure the sysclk clock to 48M

InitTick( 48000000 ); //Initialize SysTick

int32_t main(void)
{
		GPIO_InitTypeDef GPIO_InitStruct = {0};
		rcc_config();
		init_uart();
	
    InitTick( 48000000 );                  //初始化SysTick

    __RCC_GPIOC_CLK_ENABLE();

    GPIO_InitStruct.IT = GPIO_IT_NONE;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pins = LED_GPIO_PINS;

    GPIO_Init(LED_GPIO_PORT, &GPIO_InitStruct);

    while (1)
    {
        GPIO_TogglePin(LED_GPIO_PORT, LED_GPIO_PINS);
       // Delay(0xFFFF);
				SysTickDelay(100);
    }
}

3. Program running

The oscilloscope tests LED2 port PC10, the waveform is as follows

The delay is 100ms, and the test delay time is 102ms. There is a certain deviation when using the internal clock.

火辣西米秀

Sysclk delay is the basic skill of programming, test it well, and the main thing is configuration

TL-LED

Hot Ximi Show posted on 2023-7-19 23:05 Sysclk delay is the basic skill of programming. Test it well, and the main thing is configuration

Yes, the heartbeat of the operating system

hillmailbox

Before SYSCLK switches to HSI 48MHz, FLASH needs to configure the read wait cycle. FLASH_SetLatency(FLASH_Latency_2);

freebsder

Did you use the official generated code?

TL-LED

freebsder posted on 2023-7-26 19:15 Is the official generated code used?

Well, the library is official.

freebsder

TL-LED posted on 2023-7-26 20:11 Well, the library is official

The quality is worrying, haha