Resolved! STM32L552-EV, attempting to IAP program the flash through UART connection, however always fails to send the bin file through Y-modem protocol.
I've been using the example AN4657 and following it to a T. I'm using the example project library files form the STM32L476G IAP_Main and modified them where necessary to work with the 552.I can successfully connect to TeraTerm via usart3 connection a...