The question is related to SmartBridge init scenario.
I would like to know about wiced_result_t bt_firmware_download function (SDK3.1.2 , libraries/bluetooth/internal/firmware/bt_firmware.c)
Is that mean download f/w from MCU to bt's RAM (20702) or download it to bt's external SPI flash ? external memory on bt module is necessary or not ?
The bluetooth firmware is download to the RAM in the BCM20702 and started to run upon download.
With this setup, BCM20702 paired with host MCU, serial flash is not needed because firmware can be downloaded by the host MCU.