8.4.6.8.4 End of Frame Procedure

If the QSPI needs reconfiguring, first apply the following procedure to close the current frame safely:
  1. Wait for QSPI_SR.RBUSY=0 and QSPI_SR.HIDLE=1.
  2. Send a QSPI_CR.LASTXFER command.
  3. If QSPI_SR.CSS=0 or QSPI_SR.CSS1=0, wait for QSPI_ISR.CSRA=1.
  4. Set QSPI_CR.QSPIDIS and wait for QSPI_SR.QSPIENS=0.
Note: Consider using a memory barrier when writing the application code before executing the above procedure.