16.5.7.6.3 Software Considerations (MRL C)

Before reading any data, the ROM code sends a software reset to the QSPI NOR memory. Then the ROM code looks for the Serial Flash Discoverable Parameters (SFDP) of the QSPI NOR memory, if available, to learn the parameters (instruction op code, timing settings) required to read the user-programmed boot file.

If SFDP tables are not available, the ROM code uses hard-coded values as fallback settings to read the boot file.

The ROM code supports any QSPI NOR memory which can provide its Serial Flash Discoverable Parameters (SFDP) as defined in the JEDEC JESD216B standard.

The supported revisions of this JEDEC standard are:
  • JESD216 (version 1.0)
  • JESD216 rev. A (version 1.5)
  • JESD216 rev. B (version 1.6)
Refer to the data sheet of the QSPI NOR memory to check compliance with any of the above JEDEC JESD216 standard revisions/versions.