1
Setup
2
Strobe
3
Hold
4
EMA_CS[n]
EMA_CS[n] (ASRAM)
EMA_A[x:0]/
EMA_BA[1:0]
EMA_A[x:0]/
EMA_BA[1:0] (ASRAM)
EMA_OE
EMA_OE (ASRAM)
EMA_D[x:0]
EMA_D[x:0] (ASRAM)
t
CS
t
CS
t
RC
(m)
t
EMA_A
t
EMA_A
t
EMA_OE
t
EMA_OE
t
SU
t
EMA_D
t
ACC
(m)
t
EMA_D
t
OH
(m)
t
H
t
COD
(m)
Example Configuration
885
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
External Memory Interface A (EMIFA)
Figure 19-25. Timing Waveform of an ASRAM Read with PCB Delays
From
, the following equations may be derived. t
cyc
is the period at which the EMIFA operates.
The W_SETUP, W_STROBE, and W_HOLD fields are programmed in terms of EMIFA cycles where as
the data sheet specifications are typically given is nano seconds. This is explains the presence of t
cyc
in
the denominator of the following equations. A minus 1 is included in the equations because each field in
CE
n
CFG is programmed in terms of EMIFA clock cycles, minus 1 cycle. For example, W_SETUP is equal
to W_SETUP width in EMIFA clock cycles minus 1 cycle.