36 MHz Cortex-M3 with 64 KB Flash — the value-line workhorse
It sits in the STM32F1 Access Line — the cost-optimised branch of the family — trading the F103's 72 MHz and full-speed USB for a lower BOM entry point while keeping the same Cortex-M3 core, peripheral set, and pinout. The 48-LQFP package (7x7 mm body) gives 37 GPIOs, plus I²C, SPI, USART, and a 10-channel 12-bit ADC.
Memory sizing and peripheral fit
The 10 KB SRAM handles a couple of moderate buffers; if your application queues Ethernet or CAN frames, budget the RAM carefully. Peripherals include DMA, a temperature sensor, POR/PDR/PVD, and a PWM-capable timer — enough for a three-phase motor drive with Hall-sensor feedback or a simple BLDC trapezoidal commutation loop.
ST lists the STM32F101C8T6 as an active product. The base product number STM32F101 covers multiple density and package variants, so a future migration up or down the family stays pin-compatible across the 48-pin LQFP options.
Flash wait states are handled automatically by the memory controller at this frequency, so no boot-time configuration is needed.