5.42 Read Manufacturer/Device ID in SPI QUAD I/O (RMDQPIO)

The Read Manufacturer/Device ID in SPI Quad I/O (RMDQPIO) instruction is used to identify the manufacturer and device ID of the memory device. Before executing this command, the IOC bit in Status Register 2 must be set to 1. The operation is initiated by issuing the 8-bit command 94H in SPI mode. After the command is accepted, the device switches to Quad I/O operation using SIO[3:0] and receives either a three-byte or four-byte address with a value of 00000000H, followed by six dummy clock cycles. The CE# signal must remain asserted low throughout the entire RMDQPIO operation.

After the dummy clock cycles, the device outputs two bytes of identification data: manufacturer (20H) and device ID (18H). The data output stream continues until the operation is terminated by a low-to-high transition on CE#.