24 MHz 8-bit MCU with 128 KB Flash — the BOM-fit tier
It comes in a 64-pin LQFP package with a 10x10 mm body — a footprint that is hand-solderable and rework-friendly with a standard hot-air station.
128 KB Flash, 6 KB RAM, 2 KB EEPROM — sizing the firmware and data budget
The 6 KB RAM handles moderate data buffers for UART or SPI transactions; if your application streams sensor data or runs a TCP/IP stack, budget the RAM against the stack's footprint. The 2 KB EEPROM is a genuine differentiator: it stores calibration constants, configuration parameters, or fault logs without needing an external serial EEPROM, and it survives 100k write cycles per the STM8S family spec.
At the hot end, the 24 MHz clock may need a wait-state adjustment if the internal oscillator drifts; ST's datasheet provides the derating curve.
64-LQFP (10x10) — rework and footprint
The 10x10 mm body has moderate thermal mass; a 260°C peak reflow profile per J-STD-020 works fine. The package is MSL 3 — bake at 125°C for 24 hours if the moisture-barrier bag has been open longer than the floor-life window.
ST lists this part as Active.