MNC-12x5/Src/board.c

#include "board.h"
#include "stm32g0xx_ll_rcc.h"
#include "stm32g0xx_ll_bus.h"
#include "stm32g0xx_ll_gpio.h"
#include "stm32g0xx_ll_usart.h"
#include "stm32g0xx_ll_dma.h"
#include "stm32g0xx_ll_dmamux.h"
#include "stm32g0xx_ll_i2c.h"

/* private variables */

/* private functions */
static void GPIO_Init(void);
static void DMA_Init(void);
static void I2C1_Init(void);
static void TIM1_Init(void);
static void TIM3_Init(void);
static void TIM14_Init(void);
static void TIM16_Init(void);
static void TIM17_Init(void);
static void USART1_UART_Init(void);

/* Board perephireal Configuration  */
void Board_Init(void)
{
  RCC->APBENR2 |= RCC_APBENR2_SYSCFGEN;
  RCC->APBENR1 |= RCC_APBENR1_PWREN;

  /* Peripheral interrupt init*/
  /* RCC_IRQn interrupt configuration */
  NVIC_SetPriority(RCC_IRQn, 0);
  NVIC_EnableIRQ(RCC_IRQn);

  /* Configure the system clock */
  SystemClock_Config();

  /* Processor uses sleep as its low power mode */
  SCB->SCR &= ~((uint32_t)SCB_SCR_SLEEPDEEP_Msk);
  /* DisableSleepOnExit */
  SCB->SCR &= ~((uint32_t)SCB_SCR_SLEEPONEXIT_Msk);

  /* Initialize all configured peripherals */
  GPIO_Init();
  DMA_Init();
  I2C1_Init();

  /* Start RGB & Tube Power PWM */
  TIM1_Init();
  TIM3_Init();

  //TIM14_Init();

  //TIM16_Init();
  //TIM17_Init();

  USART1_UART_Init();
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  /* HSI configuration and activation */
  RCC->CR |= RCC_CR_HSIKERON; // Enable HSI even in stop mode
  while((RCC->CR & RCC_CR_HSIRDY) == 0)
  {
  }

  /* Main PLL configuration and activation */
  RCC->PLLCFGR &= ~(RCC_PLLCFGR_PLLSRC | RCC_PLLCFGR_PLLM | RCC_PLLCFGR_PLLN | RCC_PLLCFGR_PLLR);
  RCC->PLLCFGR |= (RCC_PLLCFGR_PLLSRC_HSI | (9 << RCC_PLLCFGR_PLLN_Pos) | RCC_PLLCFGR_PLLR_2 | RCC_PLLCFGR_PLLR_0);
  RCC->PLLCFGR |= RCC_PLLCFGR_PLLREN; // RCC_PLL_EnableDomain_SYS
  RCC->CR |= RCC_CR_PLLON; // RCC_PLL_Enable
  while((RCC->CR & RCC_CR_PLLRDY) == 0)
  {
  }

  /* Set AHB prescaler*/
  //RCC->CFGR &= ~(RCC_CFGR_HPRE);
  //RCC->CFGR |= 0x00000000U;

  /* Sysclk activation on the main PLL */
  RCC->CFGR &= RCC_CFGR_SW;
  RCC->CFGR |= RCC_CFGR_SW_1;
  while((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_1)
  {
  }

  /* Set APB1 prescaler !!! uncorrect !!! */
  //RCC->CFGR &= RCC_CFGR_PPRE;
  //RCC->CFGR |= 0x00000000U;

  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  SystemCoreClock = 24000000;

  /* Set I2C Clock Source */
  RCC->CCIPR &= ~(RCC_CCIPR_I2C1SEL);
  RCC->CCIPR |= RCC_CCIPR_I2C1SEL_1;
}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void GPIO_Init(void)
{
  /* GPIO Ports Clock Enable */
	RCC->IOPENR |= (RCC_IOPENR_GPIOAEN | RCC_IOPENR_GPIOBEN | RCC_IOPENR_GPIOCEN);

  /* EXTI Line: falling, no pull, input */
  // mode
  EXTI->EMR1 &= ~(EXTI_IMR1_IM14);
  EXTI->EMR1 |= EXTI_IMR1_IM14;
  // TRIGGER FALLING
  EXTI->FTSR1 &= ~(EXTI_IMR1_IM14);
  EXTI->FTSR1 |= EXTI_IMR1_IM14;
  // ?
  EXTI->FTSR1 |= EXTI_IMR1_IM14;

  /* EXTI interrupt init*/
  NVIC_SetPriority(EXTI4_15_IRQn, 0);
  NVIC_EnableIRQ(EXTI4_15_IRQn);

  /* L0, L1, L2, L3 - IN-15 symbols control, PP out, high speed, pull down */
  GPIO_SetPinMode(LC0_GPIO_Port, LC0_Pin, GPIO_MODE_OUT);
  GPIO_SetPinSpeed(LC0_GPIO_Port, LC0_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(LC0_GPIO_Port, LC0_Pin, GPIO_PUPDR_DW);

  GPIO_SetPinMode(LC1_GPIO_Port, LC1_Pin, GPIO_MODE_OUT);
  GPIO_SetPinSpeed(LC1_GPIO_Port, LC1_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(LC1_GPIO_Port, LC1_Pin, GPIO_PUPDR_DW);

  GPIO_SetPinMode(LC2_GPIO_Port, LC2_Pin, GPIO_MODE_OUT);
  GPIO_SetPinSpeed(LC2_GPIO_Port, LC2_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(LC2_GPIO_Port, LC2_Pin, GPIO_PUPDR_DW);

  GPIO_SetPinMode(LC3_GPIO_Port, LC3_Pin, GPIO_MODE_OUT);
  GPIO_SetPinSpeed(LC3_GPIO_Port, LC3_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(LC3_GPIO_Port, LC3_Pin, GPIO_PUPDR_DW);

  /* Pwer Shutdown: PP out, high speed, pull down */
  GPIO_SetPinMode(SHDN_GPIO_Port, SHDN_Pin, GPIO_MODE_OUT);
  GPIO_SetPinSpeed(SHDN_GPIO_Port, SHDN_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(SHDN_GPIO_Port, SHDN_Pin, GPIO_PUPDR_DW);

  /* SPI Latch: OD out, high speed, no pull */
  GPIO_SetPinMode(Latch_GPIO_Port, Latch_Pin, GPIO_MODE_OUT);
  GPIO_SetPinOutputType(Latch_GPIO_Port, Latch_Pin, GPIO_OTYPE_OD);
  GPIO_SetPinSpeed(Latch_GPIO_Port, Latch_Pin, GPIO_OSPEED_HI);

  /* UART_Enable: PP out, low speed, no pull*/
  GPIO_SetPinMode(UART_EN_GPIO_Port, UART_EN_Pin, GPIO_MODE_OUT);

  /* UART_State: input, pull up */
  GPIO_SetPinPull(UART_ST_GPIO_Port, UART_ST_Pin, GPIO_PUPDR_UP);

  /* BTN1, BTN2, BTN3, BTN4: input, pull up */
  GPIO_SetPinPull(BTN1_GPIO_Port, BTN1_Pin, GPIO_PUPDR_UP);
  GPIO_SetPinPull(BTN2_GPIO_Port, BTN2_Pin, GPIO_PUPDR_UP);
  GPIO_SetPinPull(BTN3_GPIO_Port, BTN3_Pin, GPIO_PUPDR_UP);
  GPIO_SetPinPull(BTN4_GPIO_Port, BTN4_Pin, GPIO_PUPDR_UP);
}

/**
  * Enable DMA controller clock
  */
static void DMA_Init(void)
{

  /* Init with LL driver */
  /* DMA controller clock enable */
  RCC->AHBSMENR |= RCC_AHBENR_DMA1EN;

  /* DMA interrupt init */
  /* DMA1_Channel1_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel1_IRQn, 0);
  NVIC_EnableIRQ(DMA1_Channel1_IRQn);
  /* DMA1_Channel2_3_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel2_3_IRQn, 0);
  NVIC_EnableIRQ(DMA1_Channel2_3_IRQn);

}

/**
  * @brief I2C1 Initialization Function
  * @param None
  * @retval None
  */
static void I2C1_Init(void)
{
  /* Peripheral clock enable */
  RCC->APBENR1 |= RCC_APBENR1_I2C1EN;
  RCC->IOPENR |= RCC_IOPENR_GPIOBEN;

  /** I2C1 GPIO Configuration
  PB8   ------> I2C1_SCL
  PB9   ------> I2C1_SDA
  */
  GPIO_SetPinMode(GPIOB, GPIO_PIN_8, GPIO_MODE_AFF);
  GPIO_SetPinOutputType(GPIOB, GPIO_PIN_8, GPIO_OTYPE_OD);
  GPIO_SetPinSpeed(GPIOB, GPIO_PIN_8, GPIO_OSPEED_HI);
  GPIO_SetPinPull(GPIOB, GPIO_PIN_8, GPIO_PUPDR_UP);
  GPIO_SetAFPin_8_15(GPIOB, GPIO_PIN_8, GPIO_AF_6);

  GPIO_SetPinMode(GPIOB, GPIO_PIN_9, GPIO_MODE_AFF);
  GPIO_SetPinOutputType(GPIOB, GPIO_PIN_9, GPIO_OTYPE_OD);
  GPIO_SetPinSpeed(GPIOB, GPIO_PIN_9, GPIO_OSPEED_HI);
  GPIO_SetPinPull(GPIOB, GPIO_PIN_9, GPIO_PUPDR_UP);
  GPIO_SetAFPin_8_15(GPIOB, GPIO_PIN_9, GPIO_AF_6);

  /** I2C1 DMA Init */
  /* I2C1_RX Init: Priority medium, Memory increment, read from perephireal,
     transfer error interrupt enable, transfer complete interrupt enable */
  DMA1_Channel2->CCR = (DMA_CCR_PL_0 | DMA_CCR_MINC | DMA_CCR_TEIE | DMA_CCR_TCIE);
  /* Route DMA channel 2 to I2C1 RX */
  DMAMUX1_Channel2->CCR = 10;

  /* I2C1_TX Init: Priority medium, Memory increment, read from memory,
     transfer error interrupt enable, transfer complete interrupt enable */
  DMA1_Channel3->CCR = (DMA_CCR_PL_0 | DMA_CCR_MINC| DMA_CCR_DIR | DMA_CCR_TEIE | DMA_CCR_TCIE);
  /* Route DMA channel 3 to I2C1 TX */
  DMAMUX1_Channel3->CCR = 11;

  /** I2C Initialization: I2C_Fast */
  I2C1->TIMINGR = 0x0010061A;
  I2C1->CR2 = I2C_CR2_AUTOEND;
  I2C1->CR1 = I2C_CR1_PE;
}

/**
  * @brief TIM1 Initialization Function
  * @param None
  * @retval None
  */
static void TIM1_Init(void)
{
  /* Peripheral clock TIM1 enable */
	RCC->APBENR2 |= RCC_APBENR2_TIM1EN;
  /* Peripheral clock GPIOA enable */
	RCC->IOPENR |= RCC_IOPENR_GPIOAEN;

  /* target clock - 200 Hz */
  TIM1->PSC = TIM1_PSC; // prescaler
  TIM1->ARR = TIM1_ARR; // auto reload value
  TIM1->CR1 = TIM_CR1_ARPE;
  // initial pwm value
  TIM1->CCR1 = PWM_TUBE_INIT_VAL;
  TIM1->CCR2 = PWM_LED_INIT_VAL;
  TIM1->CCR3 = PWM_LED_INIT_VAL;
  TIM1->CCR4 = PWM_LED_INIT_VAL;
  // pwm mode 1 for 4 chanels
  TIM1->CCMR1 = (TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC2M_1 | TIM_CCMR1_OC2M_2 | TIM_CCMR1_OC1PE | TIM_CCMR1_OC2PE);
  TIM1->CCMR2 = (TIM_CCMR2_OC3M_1 | TIM_CCMR2_OC3M_2 | TIM_CCMR2_OC4M_1 | TIM_CCMR2_OC4M_2 | TIM_CCMR2_OC3PE | TIM_CCMR2_OC4PE);
  // reset int flag - not needed, int unused
  //TIM1->SR |= TIM_SR_UIF;
  TIM1->BDTR = TIM_BDTR_MOE; // enable main output
  TIM1->EGR = TIM_EGR_UG; // force timer update
  /* TIM1 CC_EnableChannel */
  TIM1->CCER = (TIM_CCER_CC1E | TIM_CCER_CC2E | TIM_CCER_CC3E | TIM_CCER_CC4E);
  /* TIM_EnableCounter */
  TIM1->CR1 |= TIM_CR1_CEN;


  /** TIM1 GPIO Configuration
		PA8 ------> TIM1_CH1
		PA9 ------> TIM1_CH2
		PA10 ------> TIM1_CH3
		PA11 [PA9] ------> TIM1_CH4
  */
  GPIO_SetPinMode(PWM_1_GPIO_Port, PWM_1_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_1_GPIO_Port, PWM_1_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_1_GPIO_Port, PWM_1_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_8_15(PWM_1_GPIO_Port, PWM_1_Pin, GPIO_AF_2);

  GPIO_SetPinMode(PWM_R_GPIO_Port, PWM_R_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_R_GPIO_Port, PWM_R_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_R_GPIO_Port, PWM_R_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_8_15(PWM_R_GPIO_Port, PWM_R_Pin, GPIO_AF_2);

  GPIO_SetPinMode(PWM_B_GPIO_Port, PWM_B_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_B_GPIO_Port, PWM_B_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_B_GPIO_Port, PWM_B_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_8_15(PWM_B_GPIO_Port, PWM_B_Pin, GPIO_AF_2);

  GPIO_SetPinMode(PWM_G_GPIO_Port, PWM_G_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_G_GPIO_Port, PWM_G_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_G_GPIO_Port, PWM_G_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_8_15(PWM_G_GPIO_Port, PWM_G_Pin, GPIO_AF_2);
}

/**
  * @brief TIM3 Initialization Function
  * @param None
  * @retval None
  */
static void TIM3_Init(void)
{
  /* Peripheral clock TIM1 enable */
	RCC->APBENR1 |= RCC_APBENR1_TIM3EN;
  /* Peripheral clock GPIOA and GPIOB enable */
	RCC->IOPENR |= (RCC_IOPENR_GPIOAEN | RCC_IOPENR_GPIOBEN);

  /* target clock - 200 Hz */
  TIM3->PSC = TIM3_PSC; // prescaler
  TIM3->ARR = TIM3_ARR; // auto reload value
  TIM3->CR1 = TIM_CR1_ARPE;
  // initial pwm value
  TIM3->CCR1 = PWM_TUBE_INIT_VAL;
  TIM3->CCR2 = PWM_TUBE_INIT_VAL;
  TIM3->CCR3 = PWM_TUBE_INIT_VAL;
  TIM3->CCR4 = PWM_TUBE_INIT_VAL;
  // pwm mode 1 for 4 chanels
  TIM3->CCMR1 = (TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC2M_1 | TIM_CCMR1_OC2M_2 | TIM_CCMR1_OC1PE | TIM_CCMR1_OC2PE);
  TIM3->CCMR2 = (TIM_CCMR2_OC3M_1 | TIM_CCMR2_OC3M_2 | TIM_CCMR2_OC4M_1 | TIM_CCMR2_OC4M_2 | TIM_CCMR2_OC3PE | TIM_CCMR2_OC4PE);
  // launch timer
  TIM3->EGR = TIM_EGR_UG; // force timer update
  /* TIM3 TIM_CC_EnableChannel */
  TIM3->CCER = (TIM_CCER_CC1E | TIM_CCER_CC2E | TIM_CCER_CC3E | TIM_CCER_CC4E);
  /* TIM3 enable */
  TIM3->CR1 |= TIM_CR1_CEN;

  /**TIM3 GPIO Configuration
  PA6   ------> TIM3_CH1
  PA7   ------> TIM3_CH2
  PB0   ------> TIM3_CH3
  PB1   ------> TIM3_CH4
  */
  GPIO_SetPinMode(PWM_5_GPIO_Port, PWM_5_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_5_GPIO_Port, PWM_5_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_5_GPIO_Port, PWM_5_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_0_7(PWM_5_GPIO_Port, PWM_5_Pin, GPIO_AF_1);

  GPIO_SetPinMode(PWM_4_GPIO_Port, PWM_4_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_4_GPIO_Port, PWM_4_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_4_GPIO_Port, PWM_4_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_0_7(PWM_4_GPIO_Port, PWM_4_Pin, GPIO_AF_1);

  GPIO_SetPinMode(PWM_3_GPIO_Port, PWM_3_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_3_GPIO_Port, PWM_3_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_3_GPIO_Port, PWM_3_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_0_7(PWM_3_GPIO_Port, PWM_3_Pin, GPIO_AF_1);

  GPIO_SetPinMode(PWM_2_GPIO_Port, PWM_2_Pin, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(PWM_2_GPIO_Port, PWM_2_Pin, GPIO_OSPEED_HI);
  GPIO_SetPinPull(PWM_2_GPIO_Port, PWM_2_Pin, GPIO_PUPDR_DW);
  GPIO_SetAFPin_0_7(PWM_2_GPIO_Port, PWM_2_Pin, GPIO_AF_1);
}

/**
  * @brief TIM14 Initialization Function
  * @param None
  * @retval None
  * @desc   "Блинкование" разрядами - 0,75/0,25 сек вкл/выкл.
  */
static void TIM14_Init(void)
{
  /* Peripheral clock enable */
  RCC->APBENR2 |= RCC_APBENR2_TIM14EN;

  /* TIM14 interrupt Init */
  NVIC_SetPriority(TIM14_IRQn, 0);
  NVIC_EnableIRQ(TIM14_IRQn);

  /* Set TIM14 for 1 sec period  */
  TIM14->PSC = TIM14_PSC;
  TIM14->ARR = TIM14_ARR;

  /* Enable:  Auto-reload preload, One-pulse mode, */
  TIM14->CR1 = (TIM_CR1_ARPE | TIM_CR1_OPM);

  /* OC or PWM? (for pwm - (TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1M_1) ) , Output compare 1 preload */
  TIM14->CCMR1 = (TIM_CCMR1_OC1M_0 | TIM_CCMR1_OC1PE);

  /* Enable Channel_1 or no needed ??? */
  TIM14->CCER = TIM_CCER_CC1E;

  /* Impulse value in msek */
  TIM14->CCR1 = TIM14_PULSE_VAL;

  /* Enable IRQ for Update end CaptureCompare envents or only CC ??? */
  //TIM14->DIER = (TIM_DIER_UIE | TIM_DIER_CC1IE);
  TIM14->DIER = TIM_DIER_CC1IE;
}

/**
 * На старте активируем все каналы, при совпадении отключаем (не)нужные.
 */
void Blink_Start(void)
{
	/* enable all channels */
	TUBE_ALL_ON;

	/* clear IRQ flag */
  TIM14->SR |= TIM_SR_CC1IF;

  /* clear counter value */
  TIM14->CNT = 0;

  /* enable timer */
  TIM14->CR1 |= TIM_CR1_CEN;
}

void Blink_Stop(void)
{
  /* disable timer */
  TIM14->CR1 &= ~(TIM_CR1_CEN);
  /* On all tubes */
  TUBE_ALL_ON;
}

/**
  * @brief TIM16 Initialization Function
  * @param None
  * @retval None
  */
static void TIM16_Init(void)
{
  /* Peripheral clock enable */
  RCC->APBENR2 |= RCC_APBENR2_TIM16EN;

  /* TIM16 interrupt Init */
  NVIC_SetPriority(TIM16_IRQn, 0);
  NVIC_EnableIRQ(TIM16_IRQn);

  /* setup clock */
  TIM16->PSC = TIM16_PSC; // prescaler
  TIM16->ARR = TIM16_ARR; // auto reload value
  TIM16->CR1 = TIM_CR1_ARPE;
  // initial pwm value
  //TIM16->CCR1 = TIM16_PWM_VAL;
  // pwm mode 1 for 1 chanel
  TIM16->CCMR1 = (TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1PE);
  // reset int flag
  TIM16->SR |= TIM_SR_UIF;
  TIM16->BDTR = TIM_BDTR_MOE; // enable main output
  TIM16->EGR = TIM_EGR_UG; // force timer update
  /* TIM16 CC_EnableChannel */
  TIM16->CCER = TIM_CCER_CC1E;
  /* TIM_EnableCounter */
  TIM16->CR1 |= TIM_CR1_CEN;
  /* Enable IRQ */
  TIM16->DIER = TIM_DIER_UIE;
}

/**
  * @brief TIM17 Initialization Function
  * @param None
  * @retval None
  */
static void TIM17_Init(void)
{
  /* Peripheral clock enable */
  RCC->APBENR2 |= RCC_APBENR2_TIM17EN;

  /* TIM17 interrupt Init */
  NVIC_SetPriority(TIM17_IRQn, 0);
  NVIC_EnableIRQ(TIM17_IRQn);

  /* setup clock */
  TIM17->PSC = TIM17_PSC; // prescaler
  TIM17->ARR = TIM17_ARR; // auto reload value
  TIM17->CR1 = TIM_CR1_ARPE;
  // initial pwm value
  //TIM17->CCR1 = TIM17_PWM_VAL;
  // pwm mode 1 for 1 chanel
  TIM17->CCMR1 = (TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1PE);
  // reset int flag
  TIM17->SR |= TIM_SR_UIF;
  TIM17->BDTR = TIM_BDTR_MOE; // enable main output
  TIM17->EGR = TIM_EGR_UG; // force timer update
  /* TIM17 CC_EnableChannel */
  TIM17->CCER = TIM_CCER_CC1E;
  /* TIM_EnableCounter */
  TIM17->CR1 |= TIM_CR1_CEN;
  /* Enable IRQ */
  TIM17->DIER = TIM_DIER_UIE;
}

/**
  * @brief USART1 Initialization Function
  * @param None
  * @retval None
  */
static void USART1_UART_Init(void)
{
  /* Peripheral clock enable */
  RCC->APBENR2 |= RCC_APBENR2_USART1EN;
  RCC->IOPENR |= RCC_IOPENR_GPIOBEN;

  /**USART1 GPIO Configuration
  PB6   ------> USART1_TX
  PB7   ------> USART1_RX
  */
  GPIO_SetPinMode(GPIOB, GPIO_PIN_6, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(GPIOB, GPIO_PIN_6, GPIO_OSPEED_HI);

  GPIO_SetPinMode(GPIOB, GPIO_PIN_7, GPIO_MODE_AFF);
  GPIO_SetPinSpeed(GPIOB, GPIO_PIN_7, GPIO_OSPEED_HI);

  /* USART1 interrupt Init */
  NVIC_SetPriority(USART1_IRQn, 0);
  NVIC_EnableIRQ(USART1_IRQn);

  USART1->CR1 |= (USART_CR1_TE |USART_CR1_RE);
  USART1->BRR = 138;

  /* USART1 Enable */
  USART1->CR1 |= USART_CR1_UE;

  /* Polling USART1 initialisation */
  while((!(USART1->ISR & USART_ISR_TEACK)) || (!(USART1->ISR & USART_ISR_REACK)))
  {
  }
}