stm32硬件开发.pdf

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AN3320
Application note
Getting started with STM32F20xxx/21xxx MCU
hardware development
Introduction
This application note is intended for system designers who require a hardware
implementation overview of the development board features such as the power supply, the
clock management, the reset control, the boot mode settings and the debug management. It
shows how to use the high-density performance line STM32F20xxx/21xxx product families
and describes the minimum hardware resources required to develop an
STM32F20xxx/21xxx application.
Detailed reference design schematics are also contained in this document with descriptions
of the ponents, interfaces and modes.





August 2011 Doc ID 18267 Rev 2 1/29

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Contents AN3320
Contents
1 Power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Independent A/D converter supply and reference voltage . . . . . . . . . . . . 7
Battery backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Power supply schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Reset & power supply supervisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Power on reset (POR) / power down reset (PDR) . . . . . . . . . . . . . . . . . . 9
Programmable voltage detector (PVD) . . . . . . . . . . . . . . . . . . . . . . . . . 10
System reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2 Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
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