本文主要是介绍W5500实现以太网通信,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
实现原理
嵌入式程序跑在STM32微控制器,通过片上SPI控制器与W5500进行通信,配置所需网络参数并与远端服务器建立链接(TCP客户端)之后发送接收数据;又或者是建立服务器(TCP服务器)等待建立链接之后收发数据。抑或是不用建立连接直接发送报文(UDP)。PHY信号变压之后通过RJ45接口收发至网线。
嵌入式程序
嵌入式程序分两个部分,第一部分是一些底层通用接口。第二部分W5500抽象供上层调用的接口。
底层通用接口
这部分实现主要包括IO口控制器初始化,以及MCU不同位宽配置芯片接口和Socket批量发送接收数据接口,代码片如下(中文注释帮助您更好的理解实现):
//IO口控制器初始化
uint8 w55_IoInit(void)
{GPIO_InitTypeDef GPIO_InitStructure;SPI_InitTypeDef SPI_InitStructure;RCC_APB2PeriphClockCmd(SPI_CS_RCC|SPI_SCLK_RCC|SPI_SO_RCC|SPI_SI_RCC|W5500_RESET_RCC|LINK_RCC|RCC_APB2Periph_AFIO,ENABLE);/*使能AFIO时钟*/RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); /*只保留SWD模式*/GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE); RCC_APB1PeriphClockCmd(W5500_SPI_CLK ,ENABLE);GPIO_StructInit(&GPIO_InitStructure);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Pin = W5500_RESET_pin;GPIO_Init(W5500_RESET_GPIO, &GPIO_InitStructure);GPIO_StructInit(&GPIO_InitStructure);GPIO_InitStructure.GPIO_Pin =SPI_CS_pin;GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(SPI_CS_GPIO, &GPIO_InitStructure);GPIO_SetBits(SPI_CS_GPIO,SPI_CS_pin);GPIO_StructInit(&GPIO_InitStructure);GPIO_InitStructure.GPIO_Pin =SPI_SCLK_pin|SPI_SI_pin|SPI_SO_pin;GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(SPI_SCLK_GPIO, &GPIO_InitStructure);GPIO_SetBits(SPI_SCLK_GPIO,SPI_SCLK_pin|SPI_SI_pin|SPI_SO_pin);RCC_APB1PeriphClockCmd(LINK_RCC ,ENABLE);GPIO_StructInit(&GPIO_InitStructure);GPIO_InitStructure.GPIO_Pin = LINK_pin;GPIO_InitStructure.GPIO_Mode= GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(LINK_GPIO, &GPIO_InitStructure);SPI_InitStructure.SPI_Direction=SPI_Direction_2Lines_FullDuplex;SPI_InitStructure.SPI_Mode=SPI_Mode_Master; SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; SPI_InitStructure.SPI_CPOL=SPI_CPOL_Low; SPI_InitStructure.SPI_CPHA=SPI_CPHA_1Edge; SPI_InitStructure.SPI_NSS=SPI_NSS_Soft; SPI_InitStructure.SPI_BaudRatePrescaler=SPI_BaudRatePrescaler_2; SPI_InitStructure.SPI_FirstBit=SPI_FirstBit_MSB; SPI_InitStructure.SPI_CRCPolynomial=7; SPI_Init(W5500_SPI, &SPI_InitStructure); SPI_Cmd(W5500_SPI,ENABLE);return 1;
}//spi发送一个字节
void SPI_Send_Byte(unsigned char dat)
{while (SPI_I2S_GetFlagStatus(W5500_SPI, SPI_I2S_FLAG_TXE) == RESET); SPI_I2S_SendData(W5500_SPI, dat);
}
//spi接收一个字节
unsigned char SPI_Recv_Byte(void)
{return (uint8)(SPI_I2S_ReceiveData(W5500_SPI));
}
//spi发送两个字节
void SPI_Send_Short(unsigned short dat)
{SPI_Send_Byte(dat/256);SPI_Send_Byte(dat);
}
//通过spi向指定地址寄存器写n个字节数据
uint8 w55_WritenByte(uint16 reg, uint8 *dat_ptr, uint16 size)
{unsigned short i;GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS); SPI_Send_Short(reg);SPI_Send_Byte(VDM|RWB_WRITE|COMMON_R);for(i=0;i<size;i++){SPI_Send_Byte(*dat_ptr++);}GPIO_SetBits(W5500_SCS_PORT, W5500_SCS); return 1;
}
//读取W5500指定地址1Byte数据
uint8 w55_Read1Byte(uint16 reg)
{unsigned char i;GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(reg);SPI_Send_Byte(FDM1|RWB_READ|COMMON_R);i=SPI_Recv_Byte();SPI_Send_Byte(0x00);i=SPI_Recv_Byte();GPIO_SetBits(W5500_SCS_PORT, W5500_SCS);return i;
}
///
//华丽的分割线
///
//单字节配置socket
uint8 w55_WriteSock1Byte(SOCKET s, uint16 reg, uint8 dat)
{GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(reg);SPI_Send_Byte(FDM1|RWB_WRITE|(s*0x20+0x08));SPI_Send_Byte(dat);GPIO_SetBits(W5500_SCS_PORT, W5500_SCS);return 1;
}
//两字节配置socket
uint8 w55_WriteSock2Byte(SOCKET s, uint16 reg, uint16 dat)
{GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(reg);SPI_Send_Byte(FDM2|RWB_WRITE|(s*0x20+0x08));SPI_Send_Short(dat);GPIO_SetBits(W5500_SCS_PORT, W5500_SCS);return 1;
}
//四字节配置socket
uint8 w55_WriteSock4Byte(SOCKET s, uint16 reg, uint8 *dat_ptr)
{GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);//ÖÃW5500µÄSCSΪµÍµçƽSPI_Send_Short(reg);SPI_Send_Byte(FDM4|RWB_WRITE|(s*0x20+0x08));SPI_Send_Byte(*dat_ptr++);SPI_Send_Byte(*dat_ptr++);SPI_Send_Byte(*dat_ptr++);SPI_Send_Byte(*dat_ptr++);GPIO_SetBits(W5500_SCS_PORT, W5500_SCS); return 1;
}
//读取Socket1字节信息
uint8 w55_ReadSock1Byte(SOCKET s, uint16 reg)
{unsigned char i;GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(reg);SPI_Send_Byte(FDM1|RWB_READ|(s*0x20+0x08));//i=SPI_I2S_ReceiveData(W5500_SPI);i=SPI_Recv_Byte();SPI_Send_Byte(0x00);//i=SPI_I2S_ReceiveData(W5500_SPI);i=SPI_Recv_Byte();GPIO_SetBits(W5500_SCS_PORT, W5500_SCS);return i;
}
//读取2字节socket信息
uint16 w55_ReadSock2Byte(SOCKET s, uint16 reg)
{unsigned short i;GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(reg);SPI_Send_Byte(FDM2|RWB_READ|(s*0x20+0x08));i=SPI_Recv_Byte();SPI_Send_Byte(0x00);i=SPI_Recv_Byte();SPI_Send_Byte(0x00);i*=256;i+=SPI_Recv_Byte();GPIO_SetBits(W5500_SCS_PORT, W5500_SCS);return i;
}
W5500抽象接口
这部分主要实现了芯片以及Socket初始化,模拟中断处理循环函数等,示例使用Socket0实现TCP客户端,您可以在此代码基础上增加配置别的Socket实现TCP服务器以及UDP等。代码片(会有中文注释帮助您更好地理解程序)如下,你会通过这部分代码片体会到C51单片机程序的编程风格(尤其是开始的两个接口):
//从Socket接收数据缓存区读取数据
uint16 w55_ReadSockToBuffer(SOCKET s, uint8 *dat_ptr)
{unsigned short rx_size;unsigned short offset, offset1;unsigned short i;unsigned char j;rx_size=w55_ReadSock2Byte(s,W5500_Sn_RX_RSR);if(rx_size==0) return 0;//没接收到数据则返回if(rx_size>S_RX_SIZE) rx_size=S_RX_SIZE; offset=w55_ReadSock2Byte(s,W5500_Sn_RX_RD);offset1=offset;offset&=(S_RX_SIZE-1);//计算实际的物理地址GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(offset);//写16位地址SPI_Send_Byte(VDM|RWB_READ|(s*0x20+0x18));//写控制字节,N字节数据长度,读数据,选择端口j=SPI_Recv_Byte();if((offset+rx_size)<S_RX_SIZE)//如果最大地址未超过w5500接收缓冲区寄存器的最大地址{for(i=0;i<rx_size;i++)//循环读取rx_size个字节数据{SPI_Send_Byte(0x00);//发送一个哑数据j=SPI_Recv_Byte();*dat_ptr=j;dat_ptr++;}}else//如果最大地址超过w5500接收缓冲区寄存器最大地址{offset=S_RX_SIZE-offset;for(i=0;i<offset;i++)//循环读出前offset个字节数据{SPI_Send_Byte(0x00); j=SPI_Recv_Byte();*dat_ptr=j;dat_ptr++;}GPIO_SetBits(W5500_SCS_PORT, W5500_SCS); GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(0x00);//写16位地址SPI_Send_Byte(VDM|RWB_READ|(s*0x20+0x18));//写控制字j=SPI_Recv_Byte();for(;i<rx_size;i++)//循环读取后rx_size-offset个字节数据{SPI_Send_Byte(0x00);j=SPI_Recv_Byte();*dat_ptr=j;dat_ptr++;}}GPIO_SetBits(W5500_SCS_PORT, W5500_SCS); offset1+=rx_size;//更新实际物理地址,即下次读取接收到的数据的起始地址w55_WriteSock2Byte(s, W5500_Sn_RX_RD, offset1);w55_WriteSock1Byte(s, W5500_Sn_CR, RECV);//发送启动接收命令return rx_size;//返回接收到的数据长度
}
//将数据写入W5500的数据发送缓冲区
uint8 w55_WriteSockToBuffer(SOCKET s, uint8 *dat_ptr, uint16 size)
{unsigned short offset,offset1;unsigned short i;offset=w55_ReadSock2Byte(s,W5500_Sn_TX_WR);offset1=offset;offset&=(S_TX_SIZE-1);//计算实际物理地址GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(offset);SPI_Send_Byte(VDM|RWB_WRITE|(s*0x20+0x10));if((offset+size)<S_TX_SIZE)//如果最大地址未超过W5500发送缓冲区寄存器的最大地址{for(i=0;i<size;i++){SPI_Send_Byte(*dat_ptr++); }}else//如果最大地址超过w5500发送缓冲区寄存器的最大地址{offset=S_TX_SIZE-offset;for(i=0;i<offset;i++){SPI_Send_Byte(*dat_ptr++);}GPIO_SetBits(W5500_SCS_PORT, W5500_SCS); GPIO_ResetBits(W5500_SCS_PORT, W5500_SCS);SPI_Send_Short(0x00);SPI_Send_Byte(VDM|RWB_WRITE|(s*0x20+0x10));for(;i<size;i++){SPI_Send_Byte(*dat_ptr++);}}GPIO_SetBits(W5500_SCS_PORT, W5500_SCS); offset1+=size;//更新实际物理地址,即下次写待发送数据到发送数据缓冲区起始地址w55_WriteSock2Byte(s, W5500_Sn_TX_WR, offset1);w55_WriteSock1Byte(s, W5500_Sn_CR, SEND);//发送启动发送指令
}
//芯片初始化
uint8 w55_StartUp(void)
{uint8 i;w55_IoInit();w55_HardwareReset();w55_Write1Byte(W5500_MODE,MODE_RST); //软复位delay(1000);//设置网关的IP地址w55_WritenByte(W5500_GAR, s_app_w55_para.u8Gateway, 4);//设置子网掩码值w55_WritenByte(W5500_SUBR,s_app_w55_para.u8SubMask,4);//设置MAC地址w55_WritenByte(W5500_SHAR,s_app_w55_para.u8MacAddr,6); //设置w5500的IP地址w55_WritenByte(W5500_SIPR,s_app_w55_para.u8LocalIp,4); //设置发送缓冲区以及接收缓冲区大小for(i=0;i<8;i++){w55_WriteSock1Byte(i,W5500_Sn_RXBUF_SIZE, 0x02);//Socket Rx memory size=2kw55_WriteSock1Byte(i,W5500_Sn_TXBUF_SIZE, 0x02);//Socket Tx mempry size=2k } //设置重连时间为200msw55_Write2Byte(W5500_RTR, 0x07d0); //设置重连次数为8次w55_Write1Byte(W5500_RCR,8);w55_Write1Byte(W5500_IMR,IM_IR7|IM_IR6);w55_WriteSock1Byte(W55_SOCKETSERVER,W5500_Sn_IMR,(IMR_SENDOK|IMR_TIMEOUT|IMR_RECV|IMR_DISCON|IMR_CON));w55_WriteSock1Byte(W55_SOCKETCLIENT,W5500_Sn_IMR,(IMR_SENDOK|IMR_TIMEOUT|IMR_RECV|IMR_DISCON|IMR_CON));w55_WriteSock1Byte(W55_SOCKETUDP,W5500_Sn_IMR,(IMR_SENDOK|IMR_TIMEOUT|IMR_RECV|IMR_DISCON|IMR_CON));w55_WriteSock1Byte(W55_SOCKETLISTEN,W5500_Sn_IMR,(IMR_SENDOK|IMR_TIMEOUT|IMR_RECV|IMR_DISCON|IMR_CON));
}//Socket初始化
uint8 w55_SocketInit(SOCKET s)
{switch(s) {case 0: //将socket0用作Tcp客户端w55_WriteSock2Byte(s, W5500_Sn_MSSR, 1460);//设置最大字节分片数//设置源端口号w55_WriteSock2Byte(s, W5500_Sn_PORT, s_app_w55_para.u16UpPort);//设置目标(远程)端口号w55_WriteSock2Byte(1, W5500_Sn_DPORTR, s_app_w55_para.u16UpPort);//设置目标(远程)IP地址w55_WriteSock4Byte(s, W5500_Sn_DIPR, s_app_w55_para.u8UpIp); break;case 4:break;case 5:break;case 6:break;case 7:break;default:break;}
}//Tcp客户端连接
uint8 u8_app_w55_SocketConnect(SOCKET s)
{u8_drv_w55_WriteSock1Byte(s,W5500_Sn_MR,MR_TCP);u8_drv_w55_WriteSock1Byte(s,W5500_Sn_CR,OPEN);//打开Socketdelay(5);//ÑÓʱ5msif(u8_drv_w55_ReadSock1Byte(s,W5500_Sn_SR)!=SOCK_INIT){u8_drv_w55_WriteSock1Byte(s,W5500_Sn_CR,CLOSE);return FALSE;//·µ»ØFALSE(0x00)}u8_drv_w55_WriteSock1Byte(s,W5500_Sn_CR,CONNECT);//设置Socket尝试连接return TRUE;
} //循环模拟中断处理函数
uint8 w55_InterruptProcess(void)
{uint8 i,j;uint8 u8Data[50];uint16 u16Length;uint16 k;while(1){//读取当前中断标志i = w55_Read1Byte(W5500_IR);//清除中断标志 w55_Write1Byte(W5500_IR, (i&0xf0)); if((i & IR_CONFLICT) == IR_CONFLICT) {//IP冲突处理代码添加return 0;}if((i & IR_UNREACH) == IR_UNREACH) {//报文无法到达return 0;}i=w55_Read1Byte(W5500_SIR); if((i & S1_INT) == S1_INT) //Socket1用作TCP客户端 {//读取socket1中断标志j=w55_ReadSock1Byte(W55_SOCKETCLIENT,W5500_Sn_IR); //清除socket1中断标志 w55_WriteSock1Byte(W55_SOCKETCLIENT,W5500_Sn_IR,j); if(j&IR_CON)//TCP客户端模式下,成功建立连接 {//一般添加发送设备信息}if(j&IR_DISCON) //TCP模式下socket断开连接处理 {w55_WriteSock1Byte(W55_SOCKETCLIENT,W5500_Sn_CR,CLOSE);//关闭w55_SocketInit(W55_SOCKETCLIENT);// 初始化TCP客户端socket w55_SocketConnect(W55_SOCKETCLIENT);//尝试建立连接}if(j&IR_SEND_OK) //数据包发送成功{//添加发送成功相关代码}if(j&IR_RECV) //数据包接收 { memset(w55_DataTmpRC,'\0',sizeof(MAX_CIRCBUFF_SIZE_1+10)); u16Length = w55_ReadSockToBuffer(W55_SOCKETCLIENT,w55_DataTmpRC); //通知处理接收数据}if(j&IR_TIMEOUT)//Socket连接或数据传输超时处理 {w55_WriteSock1Byte(W55_SOCKETCLIENT,W5500_Sn_CR,CLOSE);//关闭w55_SocketInit(W55_SOCKETCLIENT);//初始化 w55_SocketConnect(W55_SOCKETCLIENT); //重连 }}w55_WriteSockToBuffer(7,u8test1,2);if(w55_Read1Byte(W5500_SIR) != 0) {continue;}else{break;}}
}
官网例程补充说明
W5500官网提供了包括开发板,原理图,以及参考代码和常见问题与技术服务等。参考代码又针对STM32,DSP,C8051以及基于操作系统分别提供了作为TCP客户端/服务器,UDP收发等例程。下面我们对STM32F407+W5500例程中的W5500作为TCP客户端工程进行简单的分析,具体代码可以去官网下载,我这边就不贴了。
工程中包含了DHCP/DNS客户端的实现代码,示例中并没有使用,我也就不详述了,有兴趣的可以去看看。W5500.c包含了主要的驱动实现,包含所有寄存器的定义以及用以上层调用的初始化,建立连接,发送接收等接口。考虑到MCU可能不通过SPI控制器与W5500进行通信,W5500.c实现了注册平台提供的MCU与W5500直接数据交互的函数。下面是示例工程的流程图:
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