AN2606 STM32 microcontroller system memory boot mode(5)

STM32F40xxx/41xxx is used to refer to STM32F405xx, STM32F407xx, STM32F415xx and SMT32F417xx devices.

STM32F401xB(C) is used to refer to STM32F401xB and STM32F401xC devices.STM32F401xD(E) is used to refer to STM32F401xD and STM32F401xE devices.STM32F411xx is used to refer to STM32F411xD and STM32F411xE devices.STM32F42xxx/43xxx is used to refer to STM32F427xx, STM32F429xx, STM32F437xx and STM32F439xx devices

STM32F446xx is used to refer to STM32F446xE and STM32F446xC devicesL0 Series:

STM32L05xxx/06xxx is used to refer to STM32L051xx, STM32L052xx, STM32L053xx, STM32L062xx and STM32L063xx ultralow power devices.L1 Series:

STM32L1xxx6(8/B) is used to refer to STM32L1xxV6T6, STM32L1xxV6H6, STM32L1xxR6T6, STM32L1xxR6H6, STM32L1xxC6T6, STM32L1xxC6H6, STM32L1xxV8T6, STM32L1xxV8H6, STM32L1xxR8T6, STM32L1xxR8H6, STM32L1xxC8T6, STM32L1xxC8H6, STM32L1xxVBT6, STM32L1xxVBH6, STM32L1xxRBT6, STM32L1xxRBH6, STM32L1xxCBT6 and STM32L1xxCBH6 ultralow power devices.

STM32L1xxx6(8/B)A is used to refer to STM32L1xxV6T6-A, STM32L1xxV6H6-A, STM32L1xxR6T6-A, STM32L1xxR6H6-A, STM32L1xxC6T6-A, STM32L1xxC6H6-A, STM32L1xxV8T6-A, STM32L1xxV8H6-A, STM32L1xxR8T6-A, STM32L1xxR8H6-A, STM32L1xxC8T6-A, STM32L1xxC8H6-A, STM32L1xxVBT6-A, STM32L1xxVBH6-A, STM32L1xxRBT6-A, STM32L1xxRBH6-A, STM32L1xxCBT6-A and STM32L1xxCBH6-A ultralow power devices.

STM32L1xxxC is used to refer to STM32L1xxVCT6, STM32L1xxVCH6 ,

STM32L1xxRCT6, STM32L1xxUCY6, STM32L1xxCCT6 and STM32L1xxCCU6 ultralow power devices.

STM32L1xxxD is used to refer to STM32L1xxZDT6, STM32L1xxQDH6, STM32L1xxVDT6, STM32L1xxRDY6, STM32L1xxRDT6, STM32L1xxZCT6,

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AN2606Glossary

STM32L1xxQCH6, STM32L1xxRCY6, STM32L1xxVCT6-A and STM32L1xxRCT6-A ultralow power devices.

STM32L1xxxE is used to refer to STM32L1xxZET6, STM32L1xxQEH6,

STM32L1xxVET6, STM32L1xxVEY6, and STM32L1xxRET6 ultralow power devices.L4 Series:

STM32L476xx/486xx is used to refer to STM32L476xE, STM32L476xG and STM32L486xG devices

Note:

BL_USART_Loop refers to the USART Bootloader execution loop. BL_CAN_Loop refers to the CAN Bootloader execution loop. BL_I2C_Loop refers to the I2C Bootloader execution loop. BL_SPI_Loop refers to the SPI Bootloader execution loop.

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General bootloader descriptionAN2606

3 General bootloader description

3.1 Bootloader activation

The bootloader is activated by applying one of these patterns:

Table 2. Bootloader activation patterns

PatternsPattern1Pattern2

Condition

Boot0(Pin) = 1 and Boot1(Pin) = 0Boot0(Pin) = 1 and nBoot1(bit) = 1

Boot0 (Pin)= 1, Boot1(Pin) = 0 and BFB2 (bit) = 1

Pattern3

Boot0(Pin) = 0, BFB2 (bit) = 0 and both banks don’t contain valid code Boot0(Pin) = 1, Boot1(Pin) = 0, BFB2 (bit) = 0 and both banks don’t contain

valid code

Boot0 (Pin)= 1, Boot1(Pin) = 0 and BFB2 (bit) = 1

Pattern4

Boot0(Pin) = 0, BFB2 (bit) = 0 and both banks don’t contain valid code Boot0(Pin) = 1, Boot1(Pin) = 0 and BFB2 (bit) = 0Boot0 (Pin)= 1, Boot1(Pin) = 0 and BFB2 (bit) = 0

Pattern5

Boot0(Pin) = 0, BFB2 (bit) = 1 and both banks don’t contain valid code Boot0(Pin) = 1, Boot1(Pin) = 0 and BFB2 (bit) = 1Boot0(Pin) = 1, nBoot1(bit) = 1 and nBoot0_SW(bit) = 1

Pattern6

nBoot0(bit) = 0, nBoot1(bit) = 1 and nBoot0_SW(bit) = 0Boot0(Pin) = 0, nBoot0_SW(bit) = 1 and main flash empty

Note:

The bootloader activation procedure is not the same for all STM32 products. In each STM32 product bootloader section we specify which pattern is used to execute bootloader.In addition to patterns described above, user might execute Bootloader by performing a jump to system memory from user code (refer to table 64 for system memory address). Before jumping to Bootloader user must:

Disable all peripheral clocksDisable used PLLDisable interruptsClear pending interrupts

System memory boot mode can be exited by getting out from bootloader activation condition and generating hardware reset or using Go command to execute user code.

Note:

For some products with dual bank mechanism, the jump to Bootloader might result in

jumping again to user code (and thus Bootloader communication protocol is not executed). Please refer to product's "Dual Bank Boot Implementation" flowchart for more details. i.e. In order to jump and execute Bootloader communication protocol, you might configure SYSCFG register by software to map System Memory on address 0x00000000 prior to jumping, when this feature is available.

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AN2606Note:

General bootloader description

If you choose to execute the Go command, the peripheral registers used by the bootloader are not initialized to their default reset values before jumping to the user application. They should be reconfigured in the user application if they are used. So, if the IWDG is being used in the application, the IWDG prescaler value has to be adapted to meet the requirements of the application (since the prescaler was set to its maximum value ).

3.2 Bootloader identification

Depending on the STM32 device used, the bootloader may support one or more embedded

serial peripherals used to download the code to the internal Flash memory. The bootloader identifier (ID) provides information about the supported serial peripherals.For a given STM32 device, the bootloader is identified by means of the:1.

Bootloader (protocol) version: version of the serial peripheral (USART, CAN, USB, etc.) communication protocol used in the bootloader. This version can be retrieved using the bootloader Get Version command.

Bootloader identifier (ID): version of the STM32 device bootloader, coded on one byte in the 0xXY format, where:–

X specifies the embedded serial peripheral(s) used by the device bootloader: X = 1: on …… 此处隐藏：5537字，全部文档内容请下载后查看。喜欢就下载吧 ……