keil下的gd对fm17750 nfc芯片的串口初始化和通讯c程序

以下是基于Keil的GD32F175x/6x固件库，使用USART1与FM17750 NFC芯片进行串口通讯的示例代码：

#include "gd32f1x0.h"
#include <stdio.h>

#define USARTx USART1
#define USARTx_CLK RCC_APB2Periph_USART1
#define USARTx_GPIO_CLK RCC_AHBPeriph_GPIOA
#define USARTx_GPIO_PORT GPIOA
#define USARTx_RxPin GPIO_Pin_10
#define USARTx_TxPin GPIO_Pin_9

#define USARTx_IRQn USART1_IRQn
#define USARTx_IRQHandler USART1_IRQHandler

#define BUFFER_SIZE 64

uint8_t TxBuffer[BUFFER_SIZE];
uint8_t RxBuffer[BUFFER_SIZE];

__IO uint16_t TxCount = 0;
__IO uint16_t RxCount = 0;

void USART_Config(void)
{
    USART_InitPara USART_InitStructure;
    GPIO_InitPara GPIO_InitStructure;

    RCC_AHBPeriphClock_Enable(USARTx_GPIO_CLK, ENABLE);

    GPIO_PinAFConfig(USARTx_GPIO_PORT, GPIO_PinSource9, GPIO_AF_1);
    GPIO_PinAFConfig(USARTx_GPIO_PORT, GPIO_PinSource10, GPIO_AF_1);

    GPIO_InitStructure.GPIO_Pin = USARTx_TxPin;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(USARTx_GPIO_PORT, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = USARTx_RxPin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(USARTx_GPIO_PORT, &GPIO_InitStructure);

    RCC_APB2PeriphClock_Enable(USARTx_CLK, ENABLE);

    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

    USART_Init(USARTx, &USART_InitStructure);

    USART_ITConfig(USARTx, USART_IT_RXNE, ENABLE);

    USART_Cmd(USARTx, ENABLE);
}

void USARTx_IRQHandler(void)
{
    if (USART_GetITStatus(USARTx, USART_IT_RXNE) != RESET)
    {
        RxBuffer[RxCount++] = USART_ReceiveData(USARTx);
    }
    if (USART_GetITStatus(USARTx, USART_IT_TXE) != RESET)
    {
        USART_SendData(USARTx, TxBuffer[TxCount++]);
        if (TxCount == BUFFER_SIZE)
        {
            USART_ITConfig(USARTx, USART_IT_TXE, DISABLE);
        }
    }
}

void USART_SendString(char *str)
{
    TxCount = 0;
    while (*str && (TxCount < BUFFER_SIZE))
    {
        TxBuffer[TxCount++] = *str++;
    }
    USART_ITConfig(USARTx, USART_IT_TXE, ENABLE);
}

void USART_ReceiveString(char *str)
{
    uint16_t i;
    for (i = 0; i < RxCount; i++)
    {
        *str++ = RxBuffer[i];
    }
    *str = '\0';
    RxCount = 0;
}

int main(void)
{
    USART_Config();

    char tx_str[] = "Hello FM17750";
    char rx_str[BUFFER_SIZE];

    while (1)
    {
        USART_SendString(tx_str);

        while (TxCount < BUFFER_SIZE)
            ;

        USART_ReceiveString(rx_str);

        printf("Received message: %s\n", rx_str);
    }
}

在上述代码中，我们使用USART1与FM17750 NFC芯片进行通讯。在main函数中，我们定义了一个发送字符串和接收字符串的缓冲区，并在循环中不断发送和接收数据。其中，USART_SendString函数用于发送字符串，USART_ReceiveString函数用于接收字符串。我们在接收到数据后，通过printf函数将接收到的数据打印出来。

注意：在使用该程序之前，需要先根据芯片手册，设置FM17750的串口通讯参数。