The Master OSPI configuration mode supported Octal SPI flash read
commands are listed in the following table.
| Configuration Mode | Data Width | Read Mode | Command Code (hex) | Dummy Cycles |
|---|---|---|---|---|
| OSPI | 1 | Read | 03 | - |
| OSPI | 1 | Read (4-byte) | 13 | - |
| OSPI | 8 | Octal Output fast read (4-byte) | 7C | 8 |
In the OSPI configuration mode, the Spartan UltraScale+ device initiates the configuration with the
default 4-byte (32-bit) address octal output fast read command code 7Ch and the BootROM searches for a valid header. If a
valid header is not found, the device attempts to load the image using the 4-byte
alternate addressing read command code 13h. If a
valid header is still not detected, the basic read command 03h is tried. If the configuration attempt is unsuccessful after the
third command, the BootROM increments the MultiBoot register read address offset by
32 KB and tries the OSPI command sequence again to locate a valid header in the
PDI.