stm32f2xx固件庫手冊詳細介紹了stm32f2xx的庫函數及使用方法

　　Each driver consists of a set of functions covering all peripheral features. The development of each

　　driver is driven by a common API （application programming interface） which standardizes the driver

　　structure， the functions and the parameter names.The driver source code is developed in ?Strict ANSI-C? （relaxed ANSI-C for projects and example files）。 It is fully documented and is MISRA-C 2004 compliant. Writing the whole library in ?Strict ANSI-C? makes it independent from the development tools. Only the start-up files depend on the development tools.Thanks to the Standard Peripheral Library， low-level implementation details are transparent so that

　　reusing code on a different MCU requires only to reconfigure the compiler. As a result， developers can

　　easily migrate designs across the STM32 series to quickly bring product line extensions to market

　　without any redesign. In addition， the library is built around a modular architecture that makes it easy to tailor and run it on the same MCU using hardware platforms different from ST evaluation boards.

　　The Standard Peripheral Library implements run-time failure detection by checking the input values for

　　all library functions. Such dynamic checking contributes towards enhancing the robustness of the

　　software. Run-time detection is suitable for user application development and debugging. It adds an

　　overhead which can be removed from the final application code to minimize code size and execution