Embedded designers typically use three main types of memories – on-chip Flash, parallel Flash and serial Flash. On-chip Flash, ranging from as little as 8 Kb to as much as 1 Mb on LPC ARM microcontrollers, is the fastest and most secure solution, but since it is built on a microcontroller fab process, it is the most expensive of the three options. Parallel Flash, typically offered in 8-bit and 16-bit data options, is fast, although not as fast as on-chip Flash. However, it is only available in larger packages, uses a large number of pins on the MCU for interface and is relatively expensive. Serial Flash, the lowest cost of the three options, comes in small packages and uses only a few pins of the MCU, but when connected via a standard peripheral interface or SPI is very slow. SPIFI combined with quad SPI Flash offers the performance of parallel flash with the low cost and in the small packages of serial Flash.