[问答]

如何使用LSE 32.768kHz晶振设置RTCC？

问答对人有帮助，内容完整，我也想知道答案 0 硬件 1：带 LSE 晶体的 STM32F767ZGT6 型号：CM9V-T1A-32.768KHZ-7PF-20PPM-TA-QC 制造商：Micro Crystal AG 硬件 2：带 LSE 晶体的 STM32F767IIT6 型号：ECS-.327-12.5-12R-C-TR 制造商：ECS Inc 编译器： IAR Workbench v8.32.1 驱动： STM32Cube_FW_F7_V1.15.0 你好。我有两个 PCB 设计，其中包含从 AN4759 中选择的上述不同 MCU 和 LSE 晶体。但是，HAL_RTC_Init(…) 通常会失败，并且当它正常工作时，RTC 时钟非常不准确。有人可以通过代码告知我做错了什么吗？问候，安德鲁 #include "stm32f7xx_ll_bus.h" #include "stm32f7xx_ll_rcc.h" #include "stm32f7xx_ll_system.h" #include "stm32f7xx_ll_utils.h" #include "stm32f7xx_ll_gpio.h" #include "stm32f7xx_ll_rtc.h" #include "stm32f7xx_ll_pwr.h" #include "stm32f7xx_ll_cortex.h" #include "main.h" extern RTC_HandleTypeDef hRTC_Handle; int main(void) { RCC_ClkInitTypeDef RCC_ClkInitStruct; RCC_OscInitTypeDef RCC_OscInitStruct; RCC_PeriphCLKInitTypeDef PeriphClkInitStruct; HAL_StatusTypeDef ret = HAL_OK; uint8_t aShowTime[50] = {0}; uint8_t aShowDate[50] = {0}; /* Enable the CPU Cache / CPU_CACHE_Enable(); / STM32F7xx HAL library initialization / HAL_Init(); / Resets the RCC clock configuration to the default reset state. / HAL_RCC_DeInit(); / Enable HSE Oscillator and activate PLL with HSE as source / RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE; RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS; RCC_OscInitStruct.LSEState = RCC_LSE_ON; RCC_OscInitStruct.HSIState = RCC_HSI_OFF; RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT; RCC_OscInitStruct.LSIState = RCC_LSI_OFF; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE; RCC_OscInitStruct.PLL.PLLM = 24; RCC_OscInitStruct.PLL.PLLN = 400; RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; RCC_OscInitStruct.PLL.PLLQ = 8; RCC_OscInitStruct.PLL.PLLR = 2; ret = HAL_RCC_OscConfig(&RCC_OscInitStruct); if(ret != HAL_OK) { while(1) { ; } } / Activate the OverDrive to reach the 200 MHz Frequency / ret = HAL_PWREx_EnableOverDrive(); if(ret != HAL_OK) { while(1) { ; } } / Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers / RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK \| RCC_CLOCKTYPE_HCLK \| RCC_CLOCKTYPE_PCLK1 \| RCC_CLOCKTYPE_PCLK2); RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2; ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_6); if(ret != HAL_OK) { while(1) { ; } } / Select PLLSAI output as USB clock source / PeriphClkInitStruct.PeriphClockSelection = (RCC_PERIPHCLK_RTC \| RCC_PERIPHCLK_UART7 \| RCC_PERIPHCLK_CLK48 \| RCC_PERIPHCLK_UART5 \| RCC_PERIPHCLK_LTDC); PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSE; PeriphClkInitStruct.Clk48ClockSelection = RCC_CLK48SOURCE_PLLSAIP; PeriphClkInitStruct.Uart7ClockSelection = RCC_UART7CLKSOURCE_PCLK1; PeriphClkInitStruct.Uart5ClockSelection = RCC_UART5CLKSOURCE_PCLK1; PeriphClkInitStruct.PLLSAI.PLLSAIN = 192; PeriphClkInitStruct.PLLSAI.PLLSAIP = RCC_PLLSAIP_DIV4; PeriphClkInitStruct.PLLSAI.PLLSAIQ = 2; PeriphClkInitStruct.PLLSAIDivQ = 1; PeriphClkInitStruct.PLLSAI.PLLSAIR = 5; PeriphClkInitStruct.PLLSAIDivR = RCC_PLLSAIDIVR_4; if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK) { while(1) { ; } } / Setup UART DeBug Terminal / Print_DeBug_Initialise(); / Enable RTC Clock / __HAL_RCC_RTC_ENABLE(); / Setup RTCC / hRTC_Handle.Instance = RTC; hRTC_Handle.Init.HourFormat = RTC_HOURFORMAT_12; hRTC_Handle.Init.AsynchPrediv = 127; // 127 + 1 = 128 hRTC_Handle.Init.SynchPrediv = 255; // 255 + 1 = 256 32768Hz / 128 / 256 = 1Hz hRTC_Handle.Init.OutPut = RTC_OUTPUT_DISABLE; hRTC_Handle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH; hRTC_Handle.Init.OutPutType = RTC_OUTPUT_TYPE_PUSHPULL; /******************** Need to add this to allow PC13 to work as normal GPIO *******************************/ hRTC_Handle.Instance->CR &= ((uint32_t) ~(RTC_CR_COE \| RTC_CR_OSEL \| RTC_CR_TSE)); hRTC_Handle.Instance->TAMPCR &= ((uint32_t) ~(RTC_TAMPCR_TAMP1E) ); /******************* Need to add this to allow PC13 to work as normal GPIO ********************************/ ret = HAL_RTC_Init(&hRTC_Handle); if(ret != HAL_OK) { printf("ERROR - HAL_RTC_Init(&hRTC_Handle) "); } while (1) { sprintf((char)aShowTime,"%.2d:%.2d:%.2d", __LL_RTC_CONVERT_BCD2BIN(LL_RTC_TIME_GetHour(RTC)), __LL_RTC_CONVERT_BCD2BIN(LL_RTC_TIME_GetMinute(RTC)), __LL_RTC_CONVERT_BCD2BIN(LL_RTC_TIME_GetSecond(RTC))); /* Display date Format : mm-dd-yy / sprintf((char)aShowDate,"%.2d-%.2d-%.2d", __LL_RTC_CONVERT_BCD2BIN(LL_RTC_DATE_GetMonth(RTC)), __LL_RTC_CONVERT_BCD2BIN(LL_RTC_DATE_GetDay(RTC)), 2000 + __LL_RTC_CONVERT_BCD2BIN(LL_RTC_DATE_GetYear(RTC))); printf( "%s ", aShowTime ); printf( "%s ", aShowDate ); HAL_Delay(1000); } } 0
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答案对人有帮助，有参考价值 0 我发现我忘记使用 HAL_RCC_OscConfig(&RCC_OscInitStruct) 函数启用 LSE。代码应该如下所示： /* Enable HSE Oscillator and activate PLL with HSE as source / RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE \| RCC_OSCILLATORTYPE_LSI \| RCC_OSCILLATORTYPE_LSE; RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS; RCC_OscInitStruct.LSEState = RCC_LSE_ON; RCC_OscInitStruct.HSIState = RCC_HSI_OFF; RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT; RCC_OscInitStruct.LSIState = RCC_LSI_OFF; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE; RCC_OscInitStruct.PLL.PLLM = 24; RCC_OscInitStruct.PLL.PLLN = 400; RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; RCC_OscInitStruct.PLL.PLLQ = 8; RCC_OscInitStruct.PLL.PLLR = 2; ret = HAL_RCC_OscConfig(&RCC_OscInitStruct); 我还包含了看起来运行良好的 LSEDRIVE 函数。 void HAL_RTC_MspInit(RTC_HandleTypeDef hrtc) { /* Disable the write protection for RTC registers. / __HAL_RTC_WRITEPROTECTION_DISABLE(hrtc); / Enable RTC Clock / __HAL_RCC_RTC_ENABLE(); / Configures the External Low Speed oscillator (LSE) drive capability */ __HAL_RCC_LSEDRIVE_CONFIG( RCC_LSEDRIVE_MEDIUMHIGH ); } 我能够用示波器测量 512Hz 时钟作为 PC13 引脚上的输出。 HAL_RTCEx_SetCalibrationOutPut( &hRTC_Handle, RTC_CALIBOUTPUT_512HZ );

2022-12-15 09:20:32 评论举报刘再海