/**
  ******************************************************************************
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Copyright (C) Shanghai Eastsoft Microelectronics Co., Ltd. ALL rights reserved.
  *******************************************************************************
  */

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Version history:
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2019-07-17	V1.0.0	AE TEAM


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Demo introduction:
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Backup bootloader app demo
带备份的bootloader app例程

1. 提前下载好backup_boot程序
2. 下载本例程并运行，可以看到程序运行并输出编译时间
3. 重新生成该例程，可以改变编译时间
4. 使用ES32_SDK\Utilities\Add_CheckSum小工具给新生成的bin文件添加校验和
5. 使用任意支持XModem-1K协议的串口终端，将新的bin文件发送到MCU
6. 复位MCU，boot程序将自动更新APP程序，此时可看到APP程序输出的时间已变为新的时间

Test_Bin文件夹中已包含有编译完成并添加好校验信息的bin文件，两个文件的程序相同，仅编译时间不同，可用于测试
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System clock:
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External HOSC[12MHz] divided by 3, then PLL to 72MHz.

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Pin connection: 
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UART0_TX ---- PB10[GPIO_FUNC_3]
UART0_RX ---- PB11[GPIO_FUNC_3]

Note: UART0 for debug[baudrate->115200]