Hi @sharadanand
"I am setting JP2 pin 1 and 2 short and JP1 as open, I am pressing reset button and holding the ISP button while board is resetting. As per my understing of the schematic, this should automatically go into USB mode."
->>
Yes, you are correct. In this mode, the bootloader connects the device to the PC host as an MSC USB device (CRP DISABLED). The device’s flash memory appears as a drive in the host operating system, allowing you to simply drag and drop your .bin file into the MSC device.
Thank you.
BR
Alice