This application note describes the features of the SystemMemory boot mode developed for STR75x Flash microcontrollers providing all the basic functionality to support the programming of the embedded Flash. As well as the general features, this document also covers the specific features of the UART boot mode.
The document details the SystemMemory boot mode developed for STR75x Flash microcontrollers, which allows initialization of Flash programming via a serial interface. This mode is typically used when the device is woken up before the Flash memory has been programmed in the manufacturing environment.
The note covers hardware requirements, such as configuring BOOT pins and connecting an RS232 serial interface to UARTO pins. It provides a comprehensive description of supported commands including Get, Read Memory, Go, Write Memory, Erase, and various protection commands.
| Instruction Set | THUMB |
|---|---|
| CPU Mode | Supervisor Full access with IRQ Enabled and FIQs disabled |
| Input Clock Range | 2 to 10MHz |
| RAM Usage for Boot Code | Last 4K of 16K RAM (0x40003000 to 0x40003FFF) |
| Downloadable Code Space | 12K RAM (from 0x40000000 to 0x40002FFF) |
The STR75x enters this mode if the BOOT pins are configured with BOOTO=1 and BOOT1=0 during Reset.
A RS232 serial interface must be directly linked to the UARTO pins.
It allows the user to execute downloaded code by making a branch to an address specified by the user.
No, the bootloader feature is unavailable on some devices soldered on development tools like starter kits or evaluation boards.