Kinetis K21: 120MHz Cortex-M4F MCU, 512KB Flash + 128KB FlexMem, 128KB RAM, USB, Anti-tamper, 144BGA
Freescale
Freescale - MK21FN1M0VLQ12
$20.01
Freescale - MK21FN1M0VMC12
$11.01 - $11.56
Freescale - MK21FN1M0VMD12
Freescale - MK21FX512VLQ12
$17.86
Freescale - MK21FX512VMC12
$10.24