AN2606 datasheet(103/155 Pages) STMICROELECTRONICS

Part #	AN2606

Description	STM32 microcontroller system memory boot mode

PDF	155 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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DocID13801 Rev 21

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AN2606

STM32F401xB(C) devices bootloader

154

The system clock is derived from the embedded internal high-speed RC for USARTx, I2Cx

and SPIx bootloaders. This internal clock is also used for CAN and DFU (USB FS Device)

but only for the selection phase. An external clock multiple of 1 MHz (between 4 and

26 MHz) is required for CAN and DFU bootloader execution after the selection phase.

DFU bootloader

USB

Enabled

USB OTG FS configured in Forced Device

mode

USB_DM pin

Input/Output

PA11: USB DM line.

USB_DP pin

PA12: USB DP line

No external Pull-up resistor is required

TIM11

Enabled

This timer is used to determine the value of

the HSE. Once the HSE frequency is

determined, the system clock is configured

to 60 MHz using PLL and HSE.

Table 52. STM32F401xB(C) configuration in System memory boot mode (continued)

Bootloader

Feature/Peripheral

State

Comment

AN2606 Datasheet(PDF) 103 Page - STMicroelectronics