【GD32 MCU入门教程】四、GD32 MCU 常见外设介绍（10）USART 模块介绍

void usart_init(void)

{

rcu_periph_clock_enable(RCU_GPIOA);

rcu_periph_clock_enable(RCU_USART0);

#if defined GD32F10X_HD || GD32F30X_HD || GD32F20X_CL || GD32E10X

rcu_periph_clock_enable(RCU_AF);

/* connect port to USARTx_Tx */

gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_9);

/* connect port to USARTx_Rx */

gpio_init(GPIOA, GPIO_MODE_IN_FLOATING, GPIO_OSPEED_50MHZ, GPIO_PIN_10);

nvic_irq_enable(USART0_IRQn, 2U, 0U);

#elif defined GD32F1X0 || GD32F4XX || GD32F3X0 || GD32E230

#if defined GD32F1X0 || GD32F3X0 || GD32E230

/* connect port to USARTx_Tx USARTx_Rx*/

gpio_af_set(GPIOA, GPIO_AF_1, GPIO_PIN_9 | GPIO_PIN_10 );

#elif defined GD32F4XX

gpio_af_set(GPIOA, GPIO_AF_7, GPIO_PIN_9 | GPIO_PIN_10 );

#endif

#if defined GD32F1X0 || GD32F3X0 || GD32F4XX

nvic_irq_enable(USART0_IRQn, 2U, 0U);

#elif defined GD32E230

nvic_irq_enable(USART0_IRQn, 2U);

#endif

/* configure USART Tx as alternate function push-pull */

gpio_mode_set(GPIOA, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_9);

gpio_output_options_set(GPIOA, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_9);

/* configure USART Rx as alternate function push-pull */

gpio_mode_set(GPIOA, GPIO_MODE_AF, GPIO_PUPD_PULLUP, GPIO_PIN_10);

gpio_output_options_set(GPIOA, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_10);

#endif

/* USART configure */

usart_deinit(USART0);

usart_baudrate_set(USART0, 115200U);

usart_word_length_set(USART0, USART_WL_8BIT);

usart_stop_bit_set(USART0, USART_STB_1BIT);

usart_parity_config(USART0, USART_PM_NONE);

usart_hardware_flow_rts_config(USART0, USART_RTS_DISABLE);

usart_hardware_flow_cts_config(USART0, USART_CTS_DISABLE);

usart_receive_config(USART0, USART_RECEIVE_ENABLE);

usart_transmit_config(USART0, USART_TRANSMIT_ENABLE);

usart_enable(USART0);

}

/* retarget the C library printf function to the USART */

int fputc(int ch, FILE *f)

{

 usart_data_transmit(USART0, (uint8_t)ch);

 while (RESET == usart_flag_get(USART0, USART_FLAG_TBE));

 return ch;

}

void USART0_IRQHandler(void)

{

 if(RESET != usart_interrupt_flag_get(USART0, USART_INT_FLAG_RBNE)){

 /* receive data */

 rxbuffer[rxcount++] = usart_data_receive(USART0);

 if(rxcount == rx_size){

 usart_interrupt_disable(USART0, USART_INT_RBNE);

 }

 }

}

int main(void)

{

 usart_init();

printf("GD32 WELCOME");

while(txcount<tx_size)

{

while(RESET!=usart_flag_get(USART0,USART_FLAG_TBE)){

usart_data_transmit(USART0,txbuffer[txcount++]);

}

while(RESET==usart_flag_get(USART0,USART_FLAG_TC));

}

usart_interrupt_enable(USART0, USART_INT_RBNE);

/* wait until USART receive the receiver_buffer */

 while(rxcount < rx_size);

 if(rxcount == rx_size)

 printf("\n\rUSART receive successfully!\n\r");

 while(1)

{

}

}