NE20的BOOTROM大系统升级指导

在单板第一次上电之后，必须直接从串口加载Bootrom大系统，如果系统已经正常启动，那么每次升级主机软件时会自动检测大bootrom是否需要升级，如果需要，会自动通过主机软件中包含的大bootrom自动进行升级。

具体手动升级步骤如下：

（1）通过超级终端（TCL和Netterm等可能不行）正常连接Console口，波特率为9600

（2）根据超级终端上的打印信息，按Ctrl+A进入小bootrom

Press CTRL+A to Stop AutoBoot!

Starting...

===============<SMALL-BOOTROM MENU(Ver  3.01)>===============

| <1> Modify Serial Interface Parameter                                                            |

| <2> Update LargeBootrom                                                                              |

| <3> Boot main system                                                                                     |

=============================================================

Enter your choice(1-3):

可以看到小bootrom版本Ver  3.01

（3）设置波特率为115200，即选  择<1> Modify Serial Interface Parameter ，然后选

择 115200波特率：

===============<SMALL-BOOTROM MENU(Ver  3.01)>===============

| <1> Modify Serial Interface Parameter                                                            |

| <2> Update LargeBootrom                                                                              |

| <3> Boot main system                                                                                     |

=============================================================

Enter your choice(1-3):1

========================<BAUDRATE SET>=======================

|Note:  Change The HyperTerminal's Baudrate Accordingly.                               |

|-----------------------------------<Baudrate Available>-------------------------------------|

| <1> 9600(Default)                                                                                              |

| <2> 19200                                                                                                          |

| <3> 38400                                                                                                          |

| <4> 57600                                                                                                          |

| <5> 115200                                                                                                        |

==============================================================

Enter Your Choice(1-5):5

Change The BaudRate On PC Side First!

还需手动将控制台波特率改为115200，修改超级终端属性（有小手的图标），配置相连的COM口的速率为115200，然后重新连接超级终端（点击断开和拨号按钮即可），回车后出现：

The Current BaudRate is 115200

 

（4）然后选择<2>，敲入回车键，此时屏幕上应打印CCCC

===============<SMALL-BOOTROM MENU(Ver  3.01)>===============

| <1> Modify Serial Interface Parameter                                                            |

| <2> Update LargeBootrom                                                               　           |

| <3> Boot main system                                                                             　　 |

=============================================================

Enter your choice(1-3):Enter your choice(1-8): 2

Select Program File Please.

Waiting...CC

（5）选择控制台菜单：传送-》发送文件；选择待下载文件(big.bin),协议选 XMODEM； 

开始传送即可。传输完毕后会有如下提示：

Download Successfully!

Updating Large BootRom ...Done!

下载完毕后，按设置115200波特率的方式设置回9600波特率.

注意：在升级完成后一定要设置回9600，否则无法正常显示。