HAL RCC Use Cases ¶

User application sets the system at maximum frequency ¶

$@startuml participant Application participant HAL_RCC participant HAL_PWR participant HAL_FLASH participant LL_RCC participant RCC_REG participant HAL note over Application : Enable HSI oscillator Application -> HAL_RCC : HAL_RCC_HSI_Enable(HAL_RCC_HSI_DIV1) HAL_RCC -> LL_RCC : enable HSI oscillator LL_RCC --> RCC_REG LL_RCC <-- RCC_REG HAL_RCC <-- LL_RCC alt timeout (HSI Ready flag not set) HAL_RCC --> Application : HAL_ERROR else HAL_RCC --> Application : HAL_OK end note over Application : Configure PLL1 to output 520MHz on PLL1P output\n hal_rcc_pll_config_t config_pll1;\n config_pll1.pll_source = HAL_RCC_PLL_SRC_HSI;\n config_pll1.pll_m = 8;\n config_pll1.pll_n = 65;\n config_pll1.pll_p = 1;\n config_pll1.pll_q = 2;\n config_pll1.pll_r = 2;\n config_pll1.pll_s = 2;\n config_pll1.pll_t = 2;\n config_pll1.pll_fracn = 0;\n config_pll1.pll_input_range = HAL_RCC_PLL_INPUT_RANGE_4_8;\n config_pll1.pll_vco_range = HAL_RCC_PLL_VCO_RANGE_384_1672; Application -> HAL_RCC : HAL_RCC_PLL1_SetConfig(&config_pll1) alt invalid param (Parameters are not valid) HAL_RCC --> Application : HAL_INVALID_PARAM else HAL_RCC -> RCC_REG : configure PLL1 with HSI as source, PLLP is 520Mhz RCC_REG --> HAL_RCC alt already active (PLL already active) HAL_RCC --> Application : HAL_ERROR else HAL_RCC --> Application : HAL_OK end end note over Application : Enable PLL1 Application -> HAL_RCC : HAL_RCC_PLL1_Enable() HAL_RCC -> RCC_REG : enable PLL1 RCC_REG --> HAL_RCC alt timeout (PLL1 Ready flag not set) HAL_RCC --> Application : HAL_ERROR else HAL_RCC --> Application : HAL_OK end note over Application : Enable PLL1P output Application -> HAL_RCC : HAL_RCC_PLL1_EnableOutput\n(HAL_RCC_PLL1_OUTPUT_P) HAL_RCC -> LL_RCC : LL_RCC_PLL1_EnableOutput\n(LL_RCC_PLL1_OUTPUT_P) LL_RCC -> RCC_REG : Enable PLL1P output note over Application: Adjusting VOS level\nto increase performances Application -> HAL_PWR : HAL_PWR_SetMainRegulatorVoltageScalingRange\n(HAL_PWR_VOLT_SCALE_0) note over Application: Increasing the number\nof wait states\nbecause of higher\nSystem frequency Application -> HAL_FLASH : HAL_FLASH_ITF_SetLatency\n(HAL_FLASH_ITF_LATENCY_7) note over Application: Increasing the programming delay\nbecause of higher\nSystem frequency Application -> HAL_FLASH : HAL_FLASH_ITF_SetProgrammingDelay\n(HAL_FLASH_ITF_PROGRAM_DELAY_3) note over Application: Set AHBs and APBs prescalers Application -> HAL_RCC : HAL_RCC_SetBusClockConfig(&config_bus) HAL_RCC --> LL_RCC : LL_RCC_ConfigBusClock() HAL_RCC --> Application : HAL_OK note over Application : Set PLL as source\nclock of system clock Application -> HAL_RCC : HAL_RCC_SetSYSCLKSource\n(HAL_RCC_SYSCLK_SRC_PLLCLK) HAL_RCC -> LL_RCC : LL_RCC_SetSYSCLKSource\n(LL_RCC_SYS_CLKSOURCE_PLL1) LL_RCC -> RCC_REG : set system clock source HAL_RCC -> HAL_RCC : HAL_RCC_GetSYSCLKSource() alt timeout (PLL not selected as clock source) HAL_RCC --> Application : HAL_ERROR else HAL_RCC --> Application : HAL_OK end note over Application : Update SystemCoreClock Application -> HAL : HAL_UpdateCoreClock Application <-- HAL @enduml$

Called functions:

HAL_RCC_SetSYSCLKSource()

Reset the RCC clock configuration to the default system clock (HSI) ¶

$@startuml participant Application participant HAL_RCC participant LL_RCC participant HAL == HAL_RCC_ResetSystemClock function == Application -> HAL_RCC : HAL_RCC_ResetSystemClock note over HAL_RCC : Enable HSI HAL_RCC -> LL_RCC : LL_RCC_HSI_SetDivider(LL_RCC_HSI_DIV_1) HAL_RCC -> LL_RCC : LL_RCC_HSI_Enable() LL_RCC --> HAL_RCC alt timeout (HSI divider not ready) HAL_RCC --> Application : HAL_ERROR else HSI divider ready alt timeout (HSI not ready) HAL_RCC --> Application : HAL_ERROR else HSI ready note over HAL_RCC : Select HSI\nas system clock source HAL_RCC -> LL_RCC : LL_RCC_SetSysClkSource\n(LL_RCC_SYS_CLKSOURCE_HSI) LL_RCC --> HAL_RCC HAL_RCC -> LL_RCC : LL_RCC_GetSysClkSource LL_RCC --> HAL_RCC alt timeout (HSI not selected as clock source) HAL_RCC --> Application : HAL_ERROR else HSI selected as clock source HAL_RCC -> LL_RCC : LL_RCC_SetBMPrescaler\n(LL_RCC_BMCLK_PRESCALER_1) note over HAL_RCC : Set SystemCoreClock\nto HSI_VALUE HAL_RCC -> HAL: HAL_InitTick HAL --> HAL_RCC: HAL_OK HAL_RCC --> Application: HAL_OK end end end @enduml$

Called functions:

HAL_RCC_ResetSystemClock()

Enable HSE with unitary function example_1 ¶

Called functions:

HAL_RCC_HSE_Enable()

Enable HSE with unitary function example_2 ¶

Called functions:

HAL_RCC_HSE_Enable()
HAL_RCC_HSE_Disable()

Bus prescalers configuration ¶

$@startuml == Call the global HAL_RCC_SetBusClockConfig == alt Increasing the number of wait states because of higher CPU frequency Application -> HAL_FLASH : HAL_FLASH_ITF_GetLatency HAL_FLASH --> Application : return Current_latency note over Application : if HAL_FLASH_ITF_LATENCY_X > Current_latency Application -> HAL_FLASH : HAL_FLASH_ITF_SetLatency\n(HAL_FLASH_ITF_LATENCY_X) HAL_FLASH --> Application end note over Application : Fill hal_rcc_bus_clk_config_t structure\n(config_bus) alt Increasing the BUS frequency divider note over Application : if ({bus}_clk_divider > current_{bus}_clock) Application -> HAL_RCC : HAL_RCC_SetBusClockConfig\n(&config_bus) HAL_RCC -> RCC_REG : update {bus} dividers in RCC registers RCC_REG --> HAL_RCC HAL_RCC --> Application : HAL_OK end loop HSI is selected as System Clock Source end Application -> HAL_RCC : HAL_RCC_SetSYSCLKSource\n(HAL_RCC_SYSCLK_SRC_HSI) HAL_RCC -> LL_RCC : set system\n clock source LL_RCC -> RCC_REG LL_RCC <-- RCC_REG HAL_RCC <-- LL_RCC Application <-- HAL_RCC alt Decreasing the number of wait states because of lower CPU frequency Application -> HAL_FLASH : HAL_FLASH_ITF_GetLatency HAL_FLASH --> Application : return Current_latency note over Application : if HAL_FLASH_ITF_LATENCY_X < Current_latency Application -> HAL_FLASH : HAL_FLASH_ITF_SetLatency\n(HAL_FLASH_ITF_LATENCY_X) HAL_FLASH --> Application end alt Decreasing the BUS frequency divider note over Application : if ({bus}_clk_divider < current_{bus}_clock) Application -> HAL_RCC : HAL_RCC_SetBusClockConfig\n(&config_bus) HAL_RCC -> RCC_REG : update {bus} dividers in RCC registers RCC_REG --> HAL_RCC HAL_RCC --> Application : HAL_OK end @enduml$

Called functions:

Usage of HAL_RCC_SetConfigMCO ¶

$@startuml participant Application participant HAL_RCC participant HAL_GPIO participant LL_RCC == GPIO initialization outside HAL_RCC_SetConfigMCO == note over Application : Initialize MCO pin on PA8\n hal_gpio_init_t init_struct;\n init_struct.Mode = HAL_GPIO_MODE_AF_PP;\n init_struct.Speed = HAL_GPIO_SPEED_FREQ_HIGH;\n init_struct.Pull = HAL_GPIO_NOPULL;\n init_struct.Alternate = HAL_GPIO_AF0_MCO; Application -> HAL_RCC : HAL_RCC_GPIOA_EnableClock HAL_RCC -> LL_BUS : LL_AHB4_GRP1_EnableClock\n(LL_AHB4_GRP1_PERIPH_GPIOA) LL_BUS -> RCC_REG Application -> HAL_GPIO : HAL_GPIO_Init(HAL_GPIOA, &init_struct, HAL_GPIO_PIN_8) Application <-- HAL_GPIO == Call HAL_RCC_SetConfigMCO function == Application -> HAL_RCC : HAL_RCC_SetConfigMCO(HAL_RCC_MCO1_SRC_SYSCLK, \nHAL_RCC_MCO1_PRESCALER4) HAL_RCC -> LL_RCC : LL_RCC_ConfigMCO(LL_RCC_MCO1_SRC_SYSCLK, \nLL_RCC_MCO1_PRESCALER_4) LL_RCC -> RCC_REG RCC_REG --> LL_RCC HAL_RCC <-- LL_RCC Application <-- HAL_RCC @enduml$

Called functions: