These MCUs are fabricated using a high-performance silicon gate CMOS process, embedding the R8C/Tiny Series CPU core, and are packaged in a 32-pin molded-plastic LQFP. It implements sophisticated instructions for a high level of instruction efficiency. With 1 Mbyte of address space, they are capable of executing instructions at high speed. Furthermore, the R8C/27 Group has on chip data flash.

Part of models for your reference:

STM32F051K8,STM32F051C8,STM32F051R8,STM32F071V8,STM32F051T8  STM32FEBK

STM32F103T6,STM32F103ZD,STM32F101T4,STM32F102C6,STM32F102RB     STM32F100VB,STM32F105RC,STM32F105VC,STM32F103T8,STM32F101R4