AN2606 Datasheet, PDF (1/155 Pages) STMicroelectronics – STM32 microcontroller system memory boot mode

AN2606
Application note
STM32 microcontroller system memory boot mode
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, I²C, SPI, etc.). A communication protocol is defined for
each serial interface, with a compatible command set and sequences.
This document applies to the products listed in Table 1. They are referred as STM32
throughout the document.
Table 1. Applicable products
Type
Part number or product series
Microcontrollers
STM32L0 series: STM32L051xx, STM32L052xx, STM32L053xx, STM32L062xx,
STM32L063xx
STM32L1 series.
STM32L4 series: STM32L476xx, STM32L486xx
STM32F0 series: STM32F03xxx, STM32F04xxx, STM32F05xxx, STM32F07xxx
STM32F1 series.
STM32F2 series.
STM32F3 series: STM32F301xx, STM32F302xx, STM32F303xx, STM32F318xx,
STM32F328xx, STM32F334xx, STM32F358xx, STM32F373xx,
STM32F378xx
STM32F4 series: STM32F401xx, STM32F405xx, STM32F407xx, STM32F411xx,
STM32F415xx, STM32F417xx, STM32F427xx, STM32F429xx,
STM32F437xx, STM32F439xx, STM32F446xx
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 STM32 devices. 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, refer to AN3155. For the
specification of the CAN protocol used in the bootloader, refer to AN3154. For the
specification of the DFU (USB device) protocol used in the bootloader, refer to AN3156. For
the specification of the I²C protocol used in the bootloader, refer to AN4221. For the
specification of the SPI protocol used in the bootloader, refer to AN4286.
March 2015
DocID13801 Rev 21
www.st.com
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