50 MHz Cortex-M0 — what the clock buys you
Memory budget and field data
32 KB of Flash is enough for a USB HID class driver plus a command parser and some GPIO logic. The 8 KB RAM handles the USB endpoint buffers and a small data array. The separate 2 KB EEPROM is useful for calibration constants or configuration parameters that survive a firmware update — no need to wear-level the Flash for that data.
No official second-source alternate is listed, but the LPC11A11FHN33/001 shares the same Cortex-M0 core and 50 MHz speed with a slightly different peripheral set and a DAC — a candidate for evaluation if dual-sourcing becomes a priority.