[GD32L233C-START Review] 19. Low-power serial port (deep sleep wake-up, idle interrupt indefinite length data reception)

It can be seen that LPUART is connected to external interrupt 28, which is an external interrupt. This is why the serial port can wake up the MCU from sleep mode.

6. Serial port wakeup from sleep mode

7. Code Implementation

struct
{
	uint8_t RecvBuff[200];
	uint8_t RecvLen;
	uint8_t Idle:1;
}LpSerialStr;  //串口数据处理结构体

void LpuartInit(void)
{ 
	rcu_lpuart_clock_config(RCU_LPUARTSRC_IRC16MDIV);    //要进入休眠，时钟必须配置为IRC16M或LXTAL

    rcu_periph_clock_enable(RCU_GPIOA);
    rcu_periph_clock_enable(RCU_LPUART);

    /* connect port to LPUART TX */
    gpio_af_set(GPIOA, GPIO_AF_8, GPIO_PIN_2);
    /* connect port to LPUART RX */
    gpio_af_set(GPIOA, GPIO_AF_8, GPIO_PIN_3);

    /* configure LPUART TX as alternate function push-pull */
    gpio_mode_set(GPIOA, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_2);
    gpio_output_options_set(GPIOA, GPIO_OTYPE_PP, GPIO_OSPEED_10MHZ, GPIO_PIN_2);

    /* configure LPUART RX as alternate function push-pull */
    gpio_mode_set(GPIOA, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_3);
    gpio_output_options_set(GPIOA, GPIO_OTYPE_PP, GPIO_OSPEED_10MHZ, GPIO_PIN_3);

    /* LPUART configure */
    lpuart_deinit();
	
    lpuart_word_length_set(LPUART_WL_8BIT);
    lpuart_stop_bit_set(LPUART_STB_1BIT);
    lpuart_parity_config(LPUART_PM_NONE);
    lpuart_baudrate_set(115200U);
    lpuart_receive_config(LPUART_RECEIVE_ENABLE);
    lpuart_transmit_config(LPUART_TRANSMIT_ENABLE);
	
	exti_init(EXTI_28, EXTI_INTERRUPT, EXTI_TRIG_BOTH); //外部中断28配置
	nvic_irq_enable(LPUART_WKUP_IRQn, 0);              //休眠唤醒中断使能

	lpuart_wakeup_mode_config(LPUART_WUM_RBNE );    //唤醒方式，一定要在串口使能之前配置

	lpuart_wakeup_enable();
    lpuart_interrupt_enable(LPUART_INT_WU);         //休眠唤醒中断
	
	lpuart_enable();                             

	lpuart_interrupt_enable(LPUART_INT_RBNE);       //接收中断
	
	while(RESET == lpuart_flag_get(LPUART_FLAG_IDLE)){};
    lpuart_flag_clear(LPUART_FLAG_IDLE);
	
	lpuart_interrupt_enable(LPUART_INT_IDLE);       //空闲中断
		
	nvic_irq_enable(LPUART_IRQn, 3);                //低功耗串口中断使能

    void LpSerialSend(uint8_t *data,uint8_t len);
	LpSerialSend((uint8_t *)"enter\r\n",7);
		
	rcu_periph_clock_enable(RCU_PMU);
	pmu_to_deepsleepmode(PMU_LDNPDSP_LOWDRIVE, WFI_CMD, PMU_DEEPSLEEP);  //进入休眠
	
	void system_clock_reconfig(void);
	system_clock_reconfig();                      //

	LpSerialSend((uint8_t *)"recover\r\n",9);	
}

void LpSerialRecv(uint8_t data)  //串口接收
{
	if(LpSerialStr.RecvLen<200)
	{
		LpSerialStr.RecvBuff[LpSerialStr.RecvLen++]=data;
	}
}


void LpSerialSend(uint8_t *data,uint8_t len)  //串口发送
{
	for(uint8_t i=0; i<len;i++)
	{
		while (RESET == lpuart_flag_get(LPUART_FLAG_TBE  )); 
		lpuart_data_transmit(data[i]);
		while (RESET == lpuart_flag_get(LPUART_FLAG_TC  ));//LPUART_FLAG_TBE
	}
}


void LpSerialPro(void)                  //串口接收数据处理
{
	uint8_t len[2];
		
	if(LpSerialStr.Idle&&LpSerialStr.RecvLen)
	{
		LpSerialSend((uint8_t *)"Recv:",5);
		sprintf((char *)len,"%d",LpSerialStr.RecvLen);
		LpSerialSend(len,strlen((char *)len));
		LpSerialSend((uint8_t *)"[",1);
		LpSerialSend(LpSerialStr.RecvBuff,LpSerialStr.RecvLen);

		LpSerialSend((uint8_t *)"]\r\n",3);
		LpSerialStr.RecvLen=0;
		LpSerialStr.Idle=0;
	}
}

void system_clock_reconfig(void)  //唤醒后重新配置时钟
{
    /* enable HXTAL */
    RCU_CTL |= RCU_CTL_HXTALEN;

    while(SUCCESS != rcu_osci_stab_wait(RCU_HXTAL)) {};

    /* configure AHB */
    rcu_ahb_clock_config(RCU_AHB_CKSYS_DIV1);

    /* configure APB1, APB2 */
    rcu_apb1_clock_config(RCU_APB1_CKAHB_DIV1);
    rcu_apb2_clock_config(RCU_APB2_CKAHB_DIV1);

    /* enable PLL */
    RCU_CTL |= RCU_CTL_PLLEN;

    /* select PLL as system clock */
    RCU_CFG0 &= ~RCU_CFG0_SCS;
    RCU_CFG0 |= RCU_CKSYSSRC_PLL;
}

void LPUART_IRQHandler(void)  //串口中断处理函数
{
    if(RESET != lpuart_interrupt_flag_get(LPUART_INT_FLAG_RBNE)) //接收中断
	{
		LpSerialRecv(lpuart_data_receive());
    }
	
	
	if(RESET != lpuart_interrupt_flag_get(LPUART_INT_FLAG_IDLE)) //空闲中断
	{
		lpuart_interrupt_flag_clear(LPUART_INT_FLAG_IDLE);
		LpSerialStr.Idle=1;
	}
}



void LPUART_WKUP_IRQHandler(void) //串口唤醒中断处理函数
{
    if(SET == lpuart_interrupt_flag_get(LPUART_INT_FLAG_WU)) 
	{
        lpuart_flag_clear(LPUART_FLAG_WU);
        exti_flag_clear(EXTI_28);
	}
}

8. Phenomenon

Print "enter" to prompt entering sleep mode, wake up after receiving data, print "recover", and process the serial port data received when waking up at the same time;

After that, the indefinite length data is sent, and the serial port prints out the received data after receiving it.

aprilhome

Learn, if you use a normal serial port, such as usart1, is it the same configuration?

hjl2832

Have you measured the sleep current and wake-up current? Otherwise, it is meaningless.

zqm656993

Sleep mode current 250uA

xiaoyh520

GOOD

[GD32L233C-START Review] 19. Low-power serial port (deep sleep wake-up, idle interrupt indefinite length data reception) [Copy link]

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