39.7.15.1 Protocol and Timings in Page Mode

The following figure shows the NRD and NCS timings in Page mode access.

Figure 39-33. Page Mode Read Protocol

The NRD and NCS signals are held low during all read transfers, whatever the programmed values of the setup and hold timings in the User Interface may be. Moreover, the NRD and NCS timings are identical. The pulse length of the first access to the page is defined with the NCS RD PULSE field of the

SMC PULSE register. The pulse length of subsequent accesses within the page are defined using the NRD PULSE parameter.

In Page mode, the programming of the read timings is described in the following table:

Table 39-6. Programming of Read Timings in Page Mode
Parameter Value Definition
READ MODE 'x' No impact.
NCS RD SETUP 'x' No impact.
NCS RD PULSE tpa Access time of first access to the page.
NRD SETUP 'x' No impact.
NRD PULSE tsa Access time of subsequent accesses in the page.
NRD CYCLE 'x' No impact.

The SMC does not check the coherency of timings. It will always apply the NCS RD PULSE timings as page access timing (tpa) and the NRD PULSE for accesses to the page (tsa), even if the programmed value for tpa is shorter than the programmed value for tsa.