芯片：cc2640r2fRSM 软件：smartRF flash programer 2 V1.81
现象：可以forced mass erase。但是下载时会提示：
>Initiate access to target: XDS-L5000049 using 2-pin cJTAG.
>Reading file: D:/CC2640R2F/RSM/ble5_simple_peripheral_cc2640r2lp_app/FlashROM_StackLibrary/ble5_simple_peripheral_cc2640r2lp_app.hex.
>Start flash erase ...
>Unable to start target CPU
>Reset target ...
>Reset of target successful.
请问这是什么原因？
