The Nuclei SPI (Serial Peripheral Interface) is a specialized communication interface targeting single, dual or quad SPI Flash memories. It can operate in any of the three following modes:
• Register mode: SPI sends and receives by configuring the corresponding registers.
• DMA mode: SPI DMA interface uses a stream pre-processing protocol to ease the construction of SPI transfers combining commands and data stream.
• XIP memory-mapped mode: the external Flash memory is mapped to the device address space and is seen by the
system as if it was an internal memory.