The STM32F103x4, STM32F103x6, STM32F103xC, STM32F103xD and STM32F103xE are a drop-in replacement for STM32F103x8/B medium-density devices, allowing the user to try different memory densities and providing a greater degree of freedom during the development cycle
The STM32F103xx performance line family having an embedded ARM core, is therefore compatible with all ARM tools and software
STM32F103系列使用了ARM内核，所以所有ARM开发工具和软件都可以用在STM32F103上面，好像那个KEIL就是可以用
16 or 32 Kbytes of embedded Flash is available for storing programs and data.
一般具有16KB，或者32KB FLASH
Six or ten Kbytes of embedded SRAM accessed (read/write) at CPU clock speed with 0 wait states.
一般具有6/10KB的SRAM
