For the configuration with Mode set to Quad and Slave Device set to Mixed, the core supports the commands listed in Table: Supported Commands in Quad Mode and Mixed Mode Memory, which are identical (in terms of command, address and data behavior) in Winbond, Micron, and Spansion memory devices. See the memory data sheet for command details. The commands which are not supported in this mode include fast read, dual output fast read, quad output fast read, dual i/o fast read, and quad i/o fast read. These commands are not supported by the core in mixed mode because the dummy bytes or dummy cycles are different in Winbond and Micron devices. Also in mixed mode, the volatile configuration register of Micron devices is not supported as this command is not present in the Winbond device. See Following are the unsupported Commands for Dual/Quad SPI Mode across different memories of Winbond, Micron, Spansion, and Macronix. for a list of unsupported commands.