【MCU专题】感芯科技多线程MC3172开发板免费试用——2.串口驱动_引入HAL（HardwareAbstractionLayer硬件抽象层）的概念

2.串口驱动_引入HAL（HardwareAbstractionLayer硬件抽象层）的概念

1.前言：

在嵌入式程序中，可以将软件分为硬件抽象层->组件层->应用层三类，引入HAL的概念具有如下优势：1.有利于多人协同开发：可以按三个层次对人员的工作进行分配，定义好接口，可实现三层软件同时开发，大大提高开发效率2.有利于不同平台的移植：在移植时：应用 层可不过修改，组件层修改量很少，只需要着重修改hal层就可满足要求；

有关文件结构，相对应的软件所在分层，可查看此篇文章：

2.项目概述：

基于MC3172芯片，应用软件分层概念，实现串口数据的发送。

3).软件调试：

3.1HAL层：作用：1).调用芯片的驱动2).供组件层调用接口，完成初始化和服务。

源码如下：

#include "../Inc/MC3172_hal_usart.h"

#include "../../../SYSTEM/delay/MC3172Delay.h"

void HAL_USART_SendMsg(UART_HandleTypeDef UART_Init,char pStr)

{

u32 i = 0;



while(*(pStr + i) != '\0')

{

    GPCOM_PUSH_TX_DATA(UART_Init->Instance,*(pStr + i));

    DelayNms(1);//master add delay

    i++;

}

}

void HAL_USART_Init( UART_HandleTypeDef *UART_Init)

{

INTDEV_SET_CLK_RST(UART_Init->Instance,(INTDEV_RUN|INTDEV_IS_GROUP0|INTDEV_CLK_IS_CORECLK_DIV4));

GPCOM_SET_COM_MODE(UART_Init->Instance,GPCOM_UART_MODE);



//tx

GPCOM_SET_OUT_PORT(UART_Init->Instance,( \

        GPCOM_P0_OUTPUT_DISABLE|GPCOM_P3_OUTPUT_DISABLE|GPCOM_P2_OUTPUT_DISABLE|GPCOM_P1_OUTPUT_DISABLE|UART_Init->Hardware.TxPinEnable| \

        GPCOM_P0_IS_HIGH       |GPCOM_P3_IS_TXD       |GPCOM_P2_IS_HIGH       |GPCOM_P1_IS_HIGH \

                  ));

//rx

GPCOM_SET_OVERRIDE_GPIO(UART_Init->Instance, ( \

        GPCOM_P0_OVERRIDE_GPIO|GPCOM_P1_OVERRIDE_GPIO |GPCOM_P2_OVERRIDE_GPIO|GPCOM_P3_OVERRIDE_GPIO | \

        UART_Init->Hardware.RxPinEnable \

                                          ));

GPCOM_SET_IN_PORT(UART_Init->Instance,(UART_Init->Hardware.RxPinIs));



GPCOM_SET_COM_SPEED(UART_Init->Instance,12000000,UART_Init->Init.BaudRate);

}

结构体定义及函数声明如下：

typedef struct

{

u32 BaudRate; /*!< This member configures the UART communication baud rate.

The baud rate register is computed using the following formula:

                                       - If oversampling is 16 or in LIN mode,

                                          Baud Rate Register = ((PCLKx) / ((huart->Init.BaudRate)))

                                       - If oversampling is 8,

                                          Baud Rate Register[15:4] = ((2 * PCLKx) / ((huart->Init.BaudRate)))[15:4]

                                          Baud Rate Register[3] =  0

                                          Baud Rate Register[2:0] =  (((2 * PCLKx) / ((huart->Init.BaudRate)))[3:0]) >> 1      */

u32 WordLength; /*!< Specifies the number of data bits transmitted or received in a frame.

This parameter can be a value of @ref UARTEx_Word_Length */

u32 StopBits; /*!< Specifies the number of stop bits transmitted.

This parameter can be a value of @ref UART_Stop_Bits */

u32 Parity; /*!< Specifies the parity mode.

This parameter can be a value of @ref UART_Parity

                                       [url=home.php?mod=space&uid=1902110]@NOTE[/url] When parity is enabled, the computed parity is inserted

                                             at the MSB position of the transmitted data (9th bit when

                                             the word length is set to 9 data bits; 8th bit when the

                                             word length is set to 8 data bits). */

u32 Mode; /*!< Specifies whether the Receive or Transmit mode is enabled or disabled.

This parameter can be a value of @ref UART_Mode */

u32 HwFlowCtl; /*!< Specifies whether the hardware flow control mode is enabled

or disabled.

                                       This parameter can be a value of @ref UART_Hardware_Flow_Control */

u32 OverSampling; /*!< Specifies whether the Over sampling 8 is enabled or disabled, to achieve higher speed (up to fPCLK/8).

This parameter can be a value of @ref UART_Over_Sampling */

u32 OneBitSampling; /*!< Specifies whether a single sample or three samples' majority vote is selected.

Selecting the single sample method increases the receiver tolerance to clock

                                       deviations. This parameter can be a value of @ref UART_OneBit_Sampling */

}UART_InitTypeDef;

typedef struct

{

u32                      RxPinEnable;

u32                      RxPinIs;

u32                      TxPinEnable;

}UART_HardwareTypeDef;

/**

• [url=home.php?mod=space&uid=2666770]@Brief[/url] UART handle Structure definition

*/

typedef struct

{

u32                      Instance;        /*!< UART registers base address        */



UART_InitTypeDef         Init;             /*!< UART communication parameters      */



UART_HardwareTypeDef     Hardware;

}UART_HandleTypeDef;

void HAL_USART_Init(UART_HandleTypeDef* UART_Init);

void HAL_USART_SendMsg(UART_HandleTypeDef UART_Init,char pStr);

3.2组件层：作用:1）.调用hal层接口函数，2）.实现特定硬件的初始化，仅关注重要配置参数，3).实现服务供应用层调用。

源码如下：

#include "MC3172Usart.h"

#include "../delay/MC3172Delay.h"

char USART_RX_BUF[USART_REC_LEN]={0};

UART_HandleTypeDef UART_Init;

void UartInit()//u32 gpcom_sel

{

UART_Init.Instance = GPCOM8_BASE_ADDR;

UART_Init.Init.BaudRate = 115200;

UART_Init.Hardware.RxPinEnable = GPCOM_P2_INPUT_ENABLE;

UART_Init.Hardware.RxPinIs = GPCOM_RXD_IS_P2;

UART_Init.Hardware.TxPinEnable = GPCOM_P3_OUTPUT_ENABLE;



HAL_USART_Init(&UART_Init);

}

void UartSendMsg(char* pStr)

{

HAL_USART_SendMsg(&UART_Init,pStr);

}

3.3应用层：1）.调用组件层接口，2）.注重应用的实现，不在关心硬件。

源码如下：

//uart

void UserFunction2()

{

UartInit();



while(1)

{



   DelayNms(1000);

   UartSendMsg("0123456789");

}

}

4.硬件接入：

采用MC3172芯片，串口引脚为Rx：PC2 Tx：PC3

注：从代码处查看硬件接线，参看组件层即可：

卡发版引脚图如下所示：

实际接线如下图所示

5.实际效果：

正常显示字符串如下图所示：