64.6.9.3 SPI Mode Flow Diagram

Figure 64-9. SPI Mode Flow Diagram

The figure below shows Transmit Data Register Empty (TDRE), Receive Data Register Full (RDRF) and Transmission Register Empty (TXEMPTY) status flags behavior within the QSPI_ISR during an 8-bit data transfer, without DMA.

Figure 64-10. Status Register Flags Behavior
Note: Due to the internal architecture (see Block Diagram):

  • A latency occurs between the TXEMPTY rise and the end of the frame

  • A delay occurs between the end of the frame and the RDRF flag rise