1. Reset and Clock Configuration Registers The clock setup starts with RCC (Reset and Clock Configuration. In firmware library, RCC registers are defined using structure RCC_ TypeDef In stm32f10X map h, it is defined as following Real-Time clock typedef struct Vu32 CR vu32 CFGR: Vu32 CIR yu32 APB2RSTR Vu 32APBIRSTR: Vu32 AHBENR: Vu32 APB2ENR: Vu32 APB1ENR; Vu32 BDCR yu32 CSR: 3RCC Type Def13 The clock setup starts with RCC（Reset and Clock Configuration. In firmware library, RCC registers are defined using structure RCC_TypeDef. In stm32f10x_map.h, it is defined as following: /*------------------------ Real-Time Clock -----------------------------------*/ typedef struct { vu32 CR; vu32 CFGR; vu32 CIR; vu32 APB2RSTR; vu32 APB1RSTR; vu32 AHBENR; vu32 APB2ENR; vu32 APB1ENR; vu32 BDCR; vu32 CSR; } RCC_TypeDef; 1. Reset and Clock Configuration Registers