Figure 2-23, Synchronous read and asynchronous write -38 – SMC Networks ARM PL241 User Manual
Page 58
Functional Overview
2-38
Copyright © 2006 ARM Limited. All rights reserved.
ARM DDI 0389B
Figure 2-23 Synchronous read and asynchronous write
Programming t
RC
and t
WC
when the controller operates in synchronous mode
For t
RC
:
•
when using memory devices that are not wait-enabled, you must program t
RC
to
be the number of clock cycles required before valid data is available following the
assertion of cs_n
•
when using memory devices that are wait-enabled, you must program t
RC
to be
the number of clock cycles required before wait is active and stable, following the
assertion of cs_n. That is:
t_RC = 3 + t_CEOE
Note
t_CEOE is only required if wait is asserted when oe_n goes LOW.
VPFBPFON
VPFBFONBRXWB> @
VPFBIEFONBLQB
VPFBDGGB> @
$''5$
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VPFBFVBQB> @
VPFBDGYBQB
W
75
VPFBRHBQB
VPFBZHBQB
GDWD
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VPFBGDWDBHQB
GDWD
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'$
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