SLAU319AF July 2010 – September 2022
Before sending any command to the BSL, a synchronization character (SYNC) with its value of 80h must be sent to the BSL. This character is necessary to calculate all the essential internal parameters, which maintain UART and flash memory program and erase timings. It provides the BSL system time reference. When this is received, an acknowledge DATA_ACK = 90h is sent back by the BSL to confirm successful reception.
This sequence must be done before every command that is sent to the BSL.
The synchronization character is not part of the Data Frame described in Section 2.4.