Atmel Evaluation Kit AT91SAM9X35-EK AT91SAM9X35-EK Data Sheet
Product codes
AT91SAM9X35-EK
390
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
29.14.1 Protocol and Timings in Page Mode
)
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.
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.
:
The SMC does not check the coherency of timings. It will always apply the NCS_RD_PULSE timings as page access
timing (t
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
.
A[MSB]
NCS
MCK
NRD
D[31:0]
NCS_RD_PULSE
NRD_PULSE
NRD_PULSE
tsa
tpa
tsa
A[LSB]
Table 29-7. 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