50 MHz Cortex-M0 — what the speed buys you
At 50 MHz the ARM Cortex-M0 delivers single-cycle multiply and a 2-stage pipeline, enough to handle USB packet processing, I²C/SPI polling, and a modest control loop without a peripheral DMA engine. For a design that needs USB device enumeration plus a few hundred lines of sensor polling code, this core keeps the BOM at the 32 KB Flash tier — no need to step up to a Cortex-M3 with larger memory.
Memory map and field-update reality
32 KB Flash holds the firmware image; 8 KB RAM handles stack, USB buffers, and runtime data. The 2 KB EEPROM is useful for calibration constants or configuration parameters that survive a reset without external storage. Firmware updates over USB are feasible — the ROM bootloader supports DFU (Device Firmware Upgrade) class, so no dedicated programming header is required on the board.