Introduction
The bootloader is stored in the internal boot ROM memory (system memory) of STM32
devices. It is programmed by ST during production. Its main task is to download the
application program to the internal Flash memory through one of the available serial
peripherals (USART, CAN, USB, etc.). A communication protocol is defined for each serial
interface, with a compatible command set and sequences.
The main features of the bootloader are the following:
● It uses an embedded serial interface to download the code with a predefined
communication protocol
● It transfers and updates the Flash memory code, the data, and the vector table sections
This application note presents the general concept of the bootloader. It describes the
supported peripherals and hardware requirements to be considered when using the
bootloader of any STM32 device currently in production. However the specifications of the
low-level communication protocol for each supported serial peripheral are documented in
separate documents:
● For specifications of the USART protocol used in the bootloader please refer to
AN3155
● For the specification of CAN protocol used in the bootloader please refer to AN3154
● For the specification of DFU (USB Device) protocol used in the bootloader please refer
to AN3156
Related documents (available from www.st.com)
● STM32 datasheets:
– low-, medium- and high-density STM32F101xx and STM32F103xx datasheets
– low- and medium-density STM32F100xx and STM32F102xx datasheets
– STM32F105xx/107xx connectivity line datasheet
– XL-density STM32F101xx and STM32F103xx datasheets
● STM32 reference manuals:
– STM32F101xx, STM32F102xx, STM32F103xx and STM32F105xx/107xx
reference manual (RM0008)
– low- and medium-density STM32F100xx value line reference manual (RM0041)
● STM32 Flash programming manuals
– STM32F101xx, STM32F102xx, STM32F103xx and STM32F105xx/107xx Flash
programming manual (PM0042)
– low- and medium-density STM32F100xx value line Flash programming manual
(PM0063)
– XL-density STM32F101xx and STM32F103xx programming manual (PM0068)
STM32F101xx和STM32F103xx 系统存储器引导模式.pdf (340.64 KB)