The new Quad SPI flash format, which uses a modified, six-pin SPI configuration, is much faster than traditional SPI formats. Quad SPI delivers a transfer rate of 40Mbps; the same as using two 16-bit parallel devices. Using Quad SPI is often much less expensive than the parallel approach since it uses far fewer pins and is in a much smaller package. It would seem that Quad SPI Flash would be a good replacement for parallel Flash in embedded systems, but the reality is that today's 32-bit microcontrollers are not typically designed to support Quad SPI flash at its maximum speeds. NXP has introduced the patent-pending SPI Flash Interface, SPIFI  peripheral, and Quad SPI Flash can be used by LPC ARM microcontrollers to take advantage of the many benefits of Quad SPI Flash.