STMT amp; ARM STM32 Minimum System Development Board Module For arduino STM32F103C6T6A C6T6A ARM STM32 Development Board Specifications: Model: STMT6. Core: ARM 32 Cortex-M3 CPU. 72MHz work frequency. 64K flash memory, 20K SRAM. 2.0-3.6V power, I/O. Reset(POR/PDR). 4-16MHz crystal. Size: 5.3cm x 2.2cm