本文共 2053 字，大约阅读时间需要 6 分钟。

STM32F103????????????

STM32F103??????STC?????????????ARM Cortex-M3??????????????????AHB????????????????????????????????I2C?SPI?UART?ADC?DAC?????????????????????

????????????STM32F103???????????????PLL???????????????????

1. HSI?PLL??

STM32F103?????????HSI????????PLL??????HSI????????????32.768 kHz?PLL???HSI?????????????????PLL_MUL?????????

• HSI????HSE??HSE???HSI?????????????HSE_PREDIV_DIV1???HSI??32.768 kHz??1????32.768 kHz?
• PLL????PLL_MUL????PLL_MUL???????????????PLL_MUL???16??????PLLCLK = (HSI / 2) * PLL_MUL = (32.768 kHz / 2) * 16 = 64 MHz?

2. ???????

?STM32F103??PLL?????????????????

3. PCB?HSI??

???PCB???????????

• HSI??????????????????????
• PCB??????????HSI???HSE????PLL??????
• ???????????????????????????

4. ????????

?STM32F103??????????????????

void SystemClock_Config(void)
{
    RCC_ClkInitTypeDef clkinitstruct = {0};
    RCC_OscInitTypeDef oscinitstruct = {0};
    /* ??PLL */
    oscinitstruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
    oscinitstruct.HSEState = RCC_HSE_OFF;
    oscinitstruct.HSIState = RCC_HSI_ON;
    oscinitstruct.PLL.PLLState = RCC_PLL_ON;
    oscinitstruct.PLL.PLLSource = RCC_PLLSOURCE_HSI_DIV2;
    oscinitstruct.PLL.PLLMUL = RCC_PLL_MUL16;
    if (HAL_RCC_OscConfig(&oscinitstruct) != HAL_OK)
    {
        /* ????? */
        while(1);
    }
    /* ?????? */
    clkinitstruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    clkinitstruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    clkinitstruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    clkinitstruct.APB2CLKDivider = RCC_HCLK_DIV1;
    clkinitstruct.APB1CLKDivider = RCC_HCLK_DIV2;
    if (HAL_RCC_ClockConfig(&clkinitstruct, FLASH_LATENCY_2) != HAL_OK)
    {
        /* ????? */
        while(1);
    }
}

5. ????

???????STM32F103???????????????????PLL?????????????????????????????????????????????????????????????

??????????

• ???????????PLL?????
• ?????????????????
• ????????????????????????