void clk_init(void)
{
// disable external oscillator so we can use pins PF0 , PF1
RCC_HSEConfig(RCC_HSE_OFF);
// this should be enabled already
RCC_HSI_Enable(ENABLE);
// wait for HSI to stabilize
// this is redundant
while( !RCC_GetBitState(RCC_FLAG_HSISTB) );
// this should be enabled already
RCC_CK_SYSConfig(RCC_SYSCLKSOURCE_HSI);
RCC_PLLConfig(RCC_PLLSOURCE_HSI_DIV2 , 18);
RCC_PLL_Enable(ENABLE);
// wait for pll to stablilize
// this is redundant
while( !RCC_GetBitState(RCC_FLAG_PLLSTB) );
RCC_CK_SYSConfig(RCC_SYSCLKSOURCE_PLLCLK);
// wait for clock to change to pll
while ((RCC->GCFGR & (uint32_t)RCC_GCFGR_SCSS) != (uint32_t)RCC_GCFGR_SCSS_PLL);
RCC_AHBConfig(RCC_SYSCLK_DIV1); // config ahb clock divider
RCC_APB1Config(RCC_APB1AHB_DIV1);
RCC_APB2Config(RCC_APB2AHB_DIV1);
}
/**
* @brief Select the RTC clock source.
* @param None
* @retval None
*/
void RTC_PreConfiguration(void)
{
/* Enable PWR clock */
RCC_APB1PeriphClock_Enable(RCC_APB1PERIPH_PWR, ENABLE);
/* Enable the access of the RTC registers */
PWR_BackupAccess_Enable(ENABLE);
#if defined (RTC_CLOCK_SOURCE_LSI)
RCC_LSI_Enable(ENABLE);
while(RCC_GetBitState(RCC_FLAG_LSISTB) == RESET)
{
}
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);
prescaler_s = 0x18F;
prescaler_a = 0x63;
#elif defined (RTC_CLOCK_SOURCE_LSE)
RCC_LSEConfig(RCC_LSE_EN);
while(RCC_GetBitState(RCC_FLAG_LSESTB) == RESET)
{
}
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);
prescaler_s = 0xFF;
prescaler_a = 0x7F;
#else
#error RTC Clock source should be defined.
#endif /* RTC_CLOCK_SOURCE_LSI */
RCC_RTCCLK_Enable(ENABLE);
RTC_WaitRSF_ToSetAgain();
}
/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/* Initialize four LEDs mounted on GD32107C-EVAL board */
LED_Init();
/* Enable PWR and BKP clock */
RCC_APB1PeriphClock_Enable(RCC_APB1PERIPH_PWR | RCC_APB1PERIPH_BKP, ENABLE);
/* Enable write access to the registers in Backup domain */
PWR_BackupAccess_Enable(ENABLE);
/* Clear the bit flag of Tamper Event */
BKP_ClearBitState();
/* Check if the POR/PDR reset flag is set */
if(RCC_GetBitState(RCC_FLAG_POPDRST) != RESET)
{
/* Clear the RCC all reset flags */
RCC_ClearBitState();
/* Turn on LED4 */
GPIO_SetBits(GPIOE, GPIO_PIN_0);
/* Check if Backup data registers has been written */
if(CheckBackupReg(0x1226) == 0x00)
{
/* Backup data registers values are correct */
/* Turn on LED2 */
GPIO_SetBits(GPIOC, GPIO_PIN_0);
}
else
{
/* Backup data registers values are not correct or they are not
written*/
/* Write data to Backup data registers */
WriteToBackupReg(0x1226);
/* Turn on LED3 */
GPIO_SetBits(GPIOC, GPIO_PIN_2);
}
}
/* Turn on LED5 */
GPIO_SetBits(GPIOE, GPIO_PIN_1);
while (1)
{
}
}
/**
* @brief Configure system clocks.
* @param None
* @retval None
*/
void RCC_Configuration(void)
{
/* GPIOA, GPIOB, GPIOC and GPIOF clocks enable */
RCC_AHBPeriphClock_Enable( RCC_AHBPERIPH_GPIOA |
RCC_AHBPERIPH_GPIOB |
RCC_AHBPERIPH_GPIOC |
RCC_AHBPERIPH_GPIOF , ENABLE);
/* PWR clocks enable */
RCC_APB1PeriphClock_Enable(RCC_APB1PERIPH_PWR, ENABLE);
/* Enable LSI clocks and select LSI as the clock for LCD */
PWR_BackupAccess_Enable(ENABLE);
RCC_LSI_Enable(ENABLE);
while(RCC_GetBitState(RCC_FLAG_LSISTB) == RESET)
{
}
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);
}
/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/* Configure the USART peripheral ----------------------------------------*/
USART_InitStructure.USART_BRR = 115200;
USART_InitStructure.USART_WL = USART_WL_8B;
USART_InitStructure.USART_STBits = USART_STBITS_1;
USART_InitStructure.USART_Parity = USART_PARITY_RESET;
USART_InitStructure.USART_HardwareFlowControl = USART_HARDWAREFLOWCONTROL_NONE ;
USART_InitStructure.USART_RxorTx = USART_RXORTX_RX | USART_RXORTX_TX;
GD_EVAL_COMInit(&USART_InitStructure);
printf("\n\r *********************** RTC Calendar Demo ***********************\n\r");
/* Check if RTC has aready been configured */
if (RTC->BKP0R != BKP_VALUE)
{
RTC_PreConfiguration();
RTC_Setup();
}
else
{
/* Detect the reset source */
if (RCC_GetBitState(RCC_FLAG_POPDRST) != RESET)
{
printf("\r\n Power On Reset Occurred....\n\r");
}
else if (RCC_GetBitState(RCC_FLAG_EPRST) != RESET)
{
printf("\r\n External Reset Occurred....\n\r");
}
printf("\n\r No Need To Configure RTC....\n\r");
#ifdef RTC_CLOCK_SOURCE_LSI
RCC_LSI_Enable(ENABLE);
#endif
RTC_WaitRSF_ToSetAgain();
RTC_ClearBitState(RTC_STR_AF);
EXTI_ClearIntBitState(EXTI_LINE17);
RTC_ShowTime();
RTC_ShowAlarm();
}
RCC_ClearBitState();
/* LED1 GPIO Initialization */
RCC_AHBPeriphClock_Enable(LED1_GPIO_CLK, ENABLE);
GPIO_InitStructure.GPIO_Pin = LED1_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_MODE_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OTYPE_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PUPD_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_SPEED_50MHZ;
GPIO_Init(LED1_GPIO_PORT, &GPIO_InitStructure);
LED1_GPIO_PORT->BOR = LED1_PIN;
/* LED2 GPIO Initialization */
RCC_AHBPeriphClock_Enable(LED2_GPIO_CLK, ENABLE);
GPIO_InitStructure.GPIO_Pin = LED2_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_MODE_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OTYPE_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PUPD_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_SPEED_50MHZ;
GPIO_Init(LED2_GPIO_PORT, &GPIO_InitStructure);
LED2_GPIO_PORT->BOR = LED2_PIN;
/* RTC ALARM Interrupt Configuration */
EXTI_ClearIntBitState(EXTI_LINE17);
EXTI_InitStructure.EXTI_LINE = EXTI_LINE17;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.EXTI_LINEEnable = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQ = RTC_IRQn;
NVIC_InitStructure.NVIC_IRQPreemptPriority = 0;
NVIC_InitStructure.NVIC_IRQSubPriority = 0;
NVIC_InitStructure.NVIC_IRQEnable = ENABLE;
NVIC_Init(&NVIC_InitStructure);
while (1)
{
}
}
