The AXI Quad SPI core connects the AXI4 and AXI4-Lite interfaces to SPI slave devices that support the standard, dual or quad SPI protocol instruction set. The core provides a serial interface to SPI slave devices such as SPI serial flash memory from Winbond, Micron, Spansion, and Macronix. The dual/quad SPI is an enhancement to the standard SPI protocol (described in the Motorola M68HC11 data sheet). See Specification Exceptions for differences between the core protocol and the Motorola M68HC11-Rev. 4.0 reference manual.