This document provides information on the STM32F103x8 and STM32F103xB microcontrollers. It includes specifications for the ARM Cortex-M3 CPU core, memory sizes, peripherals, and electrical characteristics. The MCUs have 64 or 128 KB of flash memory, 20 KB of SRAM, timers, ADCs, communication interfaces including USB, CAN and SPI, and are available in BGA and LQFP packages.