1.BTR17开机，模式选择到PC档或PHONE档，电脑通过USB连接BTR17解码接口，确认电脑飞傲USB驱动能正常识别BTR17，如果不能识别或没有安装驱动，请前往飞傲官网下载USB驱动
2.有打开EQ的，先把EQ关闭，电脑运行FiiO_Dfu_BTR17.exe文件，点击“Start”开始升级
3.等待升级进度条跑完即可

注：如果中途升级失败，拔插USB按照上述操作再升级一遍即可
How to update the XMOS firmware for BTR17?
Note: 1. Before upgrading the firmware for BTR17, please unplug other decoders from the USB interface on the computer, otherwise the upgrade may fail!
2. Remember to turn off EQ in BTR17 first.
Win:
1. Install Windows USB DAC driver: https://fiio-firmware.fiio.net/DAC/FiiO%20USB%20DAC%20driver%20V5.74.3.exe
2. After the BTR17 is turned on, switches the mode toggle switch on the right side  to 'PC' mode. In settings, adjust USB mode to 2.0. Then connect the ‘USB’ port in BTR17 to the computer. 
3. Double-click to open the "FiiO_Dfu_BTR17" upgrade tool, as shown in the figure below:
4. Click "Start". When "Firmware upgrade finished successfully." is displayed, it means that the XMOS firmware upgrade is successful.
MAC: 
Connect BTR17 to the MAC via USB and run the APP in the firmware package to update the firmware.