Hello Everybody,
Copying from another thread:
"... The first basic read command is performed as detailed in the table 30-428 ..., this reads back the 318 configuration bytes header stored on the flash itself, this is at 18MHz, 1-bit, SDR, there is no XiP or non-XiP here, it is purely using the basic read command, supported by all devices, the BootROM then uses these 318 bytes to configure the QuadSPI as required, see the table 19-12 in the boot section describing these bytes, which can be used to change bus width, speed, SDR/DDR as well as a bunch of other timing-related parameters.
Subsequent accesses are as set up by these 318 bytes, XiP/non-XiP is decided by the BootROM, dependent on the IVT start address..."
Regards, Naoum Gitnik.