The NXP MK22DX128VLH5 is a 32-bit ARM Cortex-M4 MCU with 128 KB Flash, 32 KB RAM, and 4 KB EEPROM on-chip, clocked at 50 MHz. It operates from 1.71 V to 3.6 V and is rated for -40 to 105 °C.
50 MHz is the nominal core clock. For a 16-bit ADC conversion at 1 Msps, the CPU has roughly 50 cycles between samples — enough to run a PID update and a Modbus packet parse without dropping a sample. The DSP single-cycle MAC and single-precision FPU on the Cortex-M4 handle the math; no need to offload to an external DSP for a three-phase motor current loop.
Memory budget: Flash, RAM, and the EEPROM block
128 KB Flash holds a FreeRTOS kernel, a USB stack, and application code for a medium-complexity node. The 32 KB RAM is split between SRAM and a FlexRAM region that can back the EEPROM emulation. The dedicated 4 KB EEPROM array stores calibration constants and fault logs without wear-leveling overhead — it eliminates the external serial EEPROM on the BOM for many designs. Watch the FlexRAM allocation in the reference manual if you need more than 4 KB of nonvolatile storage.