CC1310: Flashing CC1310 over USB on Target Board

Hi YK Chen

Many thanks for response.

Best regards

Yunus

1. What is the best way of using USB to flash CC1310? Can they use MSP430F5503 as  USB TO UART bridge and use our BSL software to flash CC1310?
The most common way of flashing CC1310 is using its 2-pin cJTAG or 4-pin JTAG debug interface. Another option is to use the CC1310's serial bootloader (which I think is what you're referring to as BSL). 
It should definitely be possible to use the MSP430 as a USB to UART bridge. For example, SmartRF Flash Programmer 2 can program CC1310 using any COM port, so that is one option.

2. Do you think that they can use FTDI FT232 as UART to USB bridge, so they can use the BSL software of CC1310?
I'm not familiar with the FT232, but for example the XDS100v3 emulator uses the FT2232 as UART to USB bridge. 

3. Is there any easy and cost-effective way to flash CC1310 using USB on the target board?
I'm not entirely sure what you are asking here. The CC1310 must be programmed using the debug interface or via its serial bootloader.

Hope this helps,
TIABO