1、功能说明
    本工程为裸机环境下（no OS）的LwIP移植示例，使用ping命令验证移植的正确性。

2、使用环境

    软件环境：
        KEIL MDK-ARM 5.34.0
        IAR EWARM 8.50.1
    
    芯片支持：
        N32H730  
        N32H735   
        N32H735EC
        N32H760
        N32H762
        N32H765
        N32H765EC
        N32H785
        N32H785EC
        N32H787

3、使用说明
    
    系统配置：
        1、时钟源：HSI+PLL
        2、时钟频率：M7：600MHz，M4：300MHz
        3、打印：PA9 - baud rate 115200

    以太网配置：
        1、PHY接口：GMII
        2、引脚分配：
            ETH1_MDC <-----> PC1
            ETH1_MDIO <-----> PA2
            ETH1_GMII_RXDV <-----> PA7
            ETH1_GMII_TXD0 <-----> PG13
            ETH1_GMII_TXD1 <-----> PG12
            ETH1_GMII_TXD2 <-----> PE3
            ETH1_GMII_TXD3 <-----> PE2
            ETH1_GMII_TXD4 <-----> PI4
            ETH1_GMII_TXD5 <-----> PI5
            ETH1_GMII_TXD6 <-----> PI6
            ETH1_GMII_TXD7 <-----> PI7
            ETH1_GMII_TXEN <-----> PG11
            ETH1_GMII_RXD0 <-----> PC4
            ETH1_GMII_RXD1 <-----> PC5
            ETH1_GMII_RXD2 <-----> PH6
            ETH1_GMII_RXD3 <-----> PH7
            ETH1_GMII_RXD4 <-----> PE12
            ETH1_GMII_RXD5 <-----> PE13
            ETH1_GMII_RXD6 <-----> PE14
            ETH1_GMII_RXD7 <-----> PE15
            ETH1_GMII_RXCLK <-----> PA1
            ETH1_GMII_COL <-----> PH3
            ETH1_GMII_CRS <-----> PA0
            ETH1_GMII_RXER <-----> PB10
            ETH1_GMII_TXER <-----> PB2
            ETH1_GMII_TXCLK <-----> PC3
            ETH1_GMII_GTXCLK <-----> PF5
            ETH1_CLK125 <-----> PD10

    使用方法：
        1、编译后下载程序运行，串口将打印本地IP地址、子网掩码、网关等信息
        2、在电脑端使用ping命令以及打印信息中的IP地址，测试网络是否畅通，以此验证移植LwIP的正确性

4、注意事项
    1、您使用的PHY芯片可能与demo默认选择的不一样，请在bsp_eth.h中切换或添加其他PHY的定义；请注意PHY_ADDR，PHY地址值必须与硬件设计保持一致
    2、开发板默认静态IP地址为：192.168.0.32，使用静态IP地址时要确保开发板与电脑处于同一网段，且无IP地址冲突


1. Function description
    This project is an example of LwIP porting in a bare-metal environment (no OS), using the ping command to verify the correctness of the port.

2. Development environment

    Software environment:
        KEIL MDK-ARM 5.34.0
        IAR EWARM 8.50.1
    
    Supported chips:
        N32H730  
        N32H735   
        N32H735EC
        N32H760
        N32H762
        N32H765
        N32H765EC
        N32H785
        N32H785EC
        N32H787

3. How to use
    
    System configuration:
        1, clock source: HSI + PLL
        2, clock frequency: M7: 600MHz, M4: 300MHz
        3, print: PA9 - baud rate 115200

    Ethernet configuration:
        1, PHY interface: GMII
        2, Pin assignment:
            ETH1_MDC <-----> PC1
            ETH1_MDIO <-----> PA2
            ETH1_GMII_RXDV <-----> PA7
            ETH1_GMII_TXD0 <-----> PG13
            ETH1_GMII_TXD1 <-----> PG12
            ETH1_GMII_TXD2 <-----> PE3
            ETH1_GMII_TXD3 <-----> PE2
            ETH1_GMII_TXD4 <-----> PI4
            ETH1_GMII_TXD5 <-----> PI5
            ETH1_GMII_TXD6 <-----> PI6
            ETH1_GMII_TXD7 <-----> PI7
            ETH1_GMII_TXEN <-----> PG11
            ETH1_GMII_RXD0 <-----> PC4
            ETH1_GMII_RXD1 <-----> PC5
            ETH1_GMII_RXD2 <-----> PH6
            ETH1_GMII_RXD3 <-----> PH7
            ETH1_GMII_RXD4 <-----> PE12
            ETH1_GMII_RXD5 <-----> PE13
            ETH1_GMII_RXD6 <-----> PE14
            ETH1_GMII_RXD7 <-----> PE15
            ETH1_GMII_RXCLK <-----> PA1
            ETH1_GMII_COL <-----> PH3
            ETH1_GMII_CRS <-----> PA0
            ETH1_GMII_RXER <-----> PB10
            ETH1_GMII_TXER <-----> PB2
            ETH1_GMII_TXCLK <-----> PC3
            ETH1_GMII_GTXCLK <-----> PF5
            ETH1_CLK125 <-----> PD10

    Usage:
        1, Compile and download the program to run, the serial port will print the local IP address, subnet mask, gateway and other information.
        2, Verify the correctness of porting the LwIP by testing that the network is open using the ping command on the computer side and the IP address in the printout.

4. Attention
    1, The PHY chip you are using may differ from the default selection in this demo. Please switch or add definitions for other PHYs in bsp_eth.h. Note that the PHY_ADDR value must match the hardware design.
    2, The default static IP address of the development board is 192.168.0.32. When using a static IP address, make sure that the board is on the same network segment as the computer and that there are no IP address conflicts.

