Protocol and Timings in Page Mode

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

Figure 1. Page Mode Read Protocol (Address MSB and LSB are defined in Table 1)

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 1. Programming of Read Timings in Page Mode
Parameter	Value	Definition
READ_MODE	'x'	No impact.
NCS_RD_SETUP	'x'	No impact.
NCS_RD_PULSE	t_pa	Access time of first access to the page.
NRD_SETUP	'x'	No impact.
NRD_PULSE	t_sa	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 (t_pa) and the NRD_PULSE for accesses to the page (t_sa), even if the programmed value for t_pa is shorter than the programmed value for t_sa.