8.4.6.2.1 Changing Frame Configuration in Serial Memory Mode (XiP)
Accesses in Serial Memory mode (QSPI_MR.SMM=1) are triggered by QSPI register accesses or by performing accesses in the QSPI memory space depending on the configuration of SMRM and TFRTYP in the Instruction Frame register (QSPI_IFR).
To modify QSPI_IFR after the initial configuration, proceed as illustrated in the figure below to ensure no frame loss. For details, see Instruction Frame and Table 8-35.