16.10.2.2 Read is Controlled by NCS (READ_MODE = 0)
The figure below shows the typical read cycle. The read data is valid tPACC after the falling edge of the NCS signal and remains valid until the rising edge of NCS. Data must be sampled when NCS is raised. In that case, the READ_MODE must be configured to 0 (read is controlled by NCS): the SMC internally samples the data on the rising edge of the main system bus clock that generates the rising edge of NCS, whatever the programmed waveform of NRD.