The SPI Flash Interface (SPIFI), a patent-pending feature initially available on NXP’s latest ARM Cortex-M3 microcontrollers, lets designers of 32-bit embedded systems use a small, inexpensive serial flash in place of a larger, more expensive parallel flash. With SPIFI (“spiffy”), the external serial flash appears in the microcontroller’s memory map and can be read like other on-chip memory. This essentially eliminates the traditional tradeoff associated with choosing the type of external flash to be used in an embedded system, and gives designers a new way to minimize size and cost while delivering the required system performance.