This document provides information on the STM32F103x8 and STM32F103xB microcontrollers. It includes specifications for the ARM Cortex-M3 CPU core, memory features including 64 or 128 KB of flash and 20 KB of SRAM, peripherals such as timers, communication interfaces, ADC, and GPIO pins. It also provides pinout diagrams, electrical characteristics, and package information for various package types including VFQFPN36, UFQFPN48, and LFBGA100.