STM 32下シリアルポートの使用

STM 32のシリアルポートに関するファームウェアライブラリはかなりよく書かれていますが、以下は本明細書のシリアルポートライブラリのほんの少しのパッケージにすぎません.

/*HKY_uart.h*/

#ifndef _HKY_UART_H_
#define _HKY_UART_H_

#include "stm32f10x_lib.h"
//#include "platform_config.h"
#define  GPIO_RTSPin              GPIO_Pin_1
#define  GPIO_CTSPin              GPIO_Pin_0
#define  GPIO_TxPin               GPIO_Pin_2
#define  GPIO_RxPin               GPIO_Pin_3

void USART2_Configuration(void);

int USART_sendBuf(USART_TypeDef* USARTx, u8 *buf, u32 len);


int USART_recvBuf(USART_TypeDef* USARTx, u8 *buf, u32 len);

#endif //_HKY_UART_H_

/*HKY_uart.c*/

#include "HKY_uart.h"

/* --------------------------------------------------------------------------*/
/** 
 * @Brief:  USART2_Configuration 
 */
/* --------------------------------------------------------------------------*/
void USART2_Configuration(void)
{
    USART_InitTypeDef USART_InitStructure;
    GPIO_InitTypeDef GPIO_InitStructure;

    //IO port----------------------------------------------------------------------
    /* Configure USART2 RTS and USART2 Tx as alternate function push-pull */
    GPIO_InitStructure.GPIO_Pin = GPIO_TxPin;//GPIO_RTSPin | GPIO_TxPin;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* Configure USART2 CTS and USART2 Rx as input floating */
    GPIO_InitStructure.GPIO_Pin = GPIO_RxPin;//GPIO_CTSPin | GPIO_RxPin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);


    /* USART2 configuration ------------------------------------------------------*/
    /* USART2 configured as follow:
	- BaudRate = 115200 baud  
	- Word Length = 8 Bits
	- One Stop Bit
	- No parity
	- Hardware flow control enabled (RTS and CTS signals)
	- Receive and transmit enabled
    */
    USART_InitStructure.USART_BaudRate = 115200;
    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_HardwareFlowControl_RTS_CTS;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

    USART_Init(USART2, &USART_InitStructure);
    /* Enable the USART2 */
    USART_Cmd(USART2, ENABLE);
    USART_ClearFlag(USART2, USART_FLAG_TC); // clear flag
}

/* --------------------------------------------------------------------------*/
/** 
 * @Brief:  USART_sendBuf 
 * 
 * @Param: USARTx, which uart port
 * @Param: buf, send buffer
 * @Param: len, buffer length
 * 
 * @Returns:   send bytes count
 */
/* --------------------------------------------------------------------------*/
int USART_sendBuf(USART_TypeDef* USARTx, u8 *buf, u32 len)
{
    u32 busy_cnt = 0;
    u32 i = 0;

    while (i < len)
    {
	USART_SendData(USARTx, buf[i++]);
	busy_cnt = 0;
	while(USART_GetFlagStatus(USARTx, USART_FLAG_TXE) == RESET)
	{
	    busy_cnt++; 
	    if (busy_cnt > 0xffff)
		return i; //send error, return sended bytes count
	}
    }
    return len; 
}

/* --------------------------------------------------------------------------*/
/** 
 * @Brief:  USART_recvBuf 
 * 
 * @Param: USARTx, which uart port
 * @Param: buf, receive buffer
 * @Param: len, buffer length
 * 
 * @Returns:  received bytes count
 */
/* --------------------------------------------------------------------------*/
int USART_recvBuf(USART_TypeDef* USARTx, u8 *buf, u32 len)
{
    u32 busy_cnt = 0;
    u32 i = 0;

    while (i < len)
    {
	if(USART_GetFlagStatus(USARTx, USART_FLAG_RXNE) != RESET)
	{
	   buf[i] = USART_ReceiveData(USARTx) & 0xff;
	   i++;
	}
	else
	{
	    busy_cnt++;
	}
	
	if (busy_cnt > 0xffff)
	    return i; //receive error, return received bytes count
    }
    return len;
}