The NXP MKL28Z512VLL7 is a 32-bit ARM Cortex-M0+ microcontroller from the Kinetis KL2 series, running at 72 MHz with 512 KB of Flash and 128 KB of RAM. The supply voltage range is 1.71 V to 3.6 V, and the operating temperature range is -40°C to 105°C.
72 MHz Cortex-M0+ — what that means on the bench
72 MHz is the top speed for this Cortex-M0+ core. The 512 KB Flash and 128 KB RAM support a bootloader plus application code. The MKL28Z512VLL7 adds FlexIO and 82 I/O pins.
The FlexIO block can emulate UART, SPI, I²C, or a custom parallel bus with programmable timing.