DSP56366 Technical Data, Rev. 3.1
3-20
Freescale Semiconductor
5
All the timings are calculated for the worst case. Some of the timings are better for specific cases (e.g., t
PC
equals 3
×
T
C
for
read-after-read or write-after-write sequences).
6
BRW[1:0] (DRAM Control Register bits) defines the number of wait states that should be inserted in each DRAM out-of-page
access.
7
RD deassertion will always occur after CAS deassertion; therefore, the restricted timing is t
OFF
and not t
GZ.
Table 3-11 DRAM Page Mode Timings, Three Wait States
1, 2, 3
No.
Characteristics
Symbol
Expression
4
Min
Max
Unit
131
Page mode cycle time for two consecutive accesses of the same
direction
Page mode cycle time for mixed (read and write) accesses
t
PC
2
×
T
C
1.25
×
T
C
40.0
35.0
—
—
ns
132
CAS assertion to data valid (read)
t
CAC
2
×
T
C
7.0
—
13.0
ns
133
Column address valid to data valid (read)
t
AA
3
×
T
C
7.0
—
23.0
ns
134
CAS deassertion to data not valid (read hold time)
t
OFF
0.0
—
ns
135
Last CAS assertion to RAS deassertion
t
RSH
2.5
×
T
C
4.0
21.0
—
ns
136
Previous CAS deassertion to RAS deassertion
t
RHCP
4.5
×
T
C
4.0
41.0
—
ns
137
CAS assertion pulse width
t
CAS
2
×
T
C
4.0
16.0
—
ns
138
Last CAS deassertion to RAS assertion
5
BRW[1:0] = 00
BRW[1:0] = 01
BRW[1:0] = 10
BRW[1:0] = 11
t
CRP
2.25
×
T
C
6.0
3.75
×
T
C
6.0
4.75
×
T
C
6.0
6.75
×
T
C
6.0
—
—
41.5
61.5
—
—
—
—
ns
139
CAS deassertion pulse width
t
CP
1.5
×
T
C
4.0
11.0
—
ns
140
Column address valid to CAS assertion
t
ASC
T
C
4.0
6.0
—
ns
141
CAS assertion to column address not valid
t
CAH
2.5
×
T
C
4.0
21.0
—
ns
142
Last column address valid to RAS deassertion
t
RAL
4
×
T
C
4.0
36.0
—
ns
143
WR deassertion to CAS assertion
t
RCS
1.25
×
T
C
4.0
8.5
—
ns
144
CAS deassertion to WR assertion
t
RCH
0.75
×
T
C
4.0
3.5
—
ns
145
CAS assertion to WR deassertion
t
WCH
2.25
×
T
C
4.2
18.3
—
ns
146
WR assertion pulse width
t
WP
3.5
×
T
C
4.5
30.5
—
ns
147
Last WR assertion to RAS deassertion
t
RWL
3.75
×
T
C
4.3
33.2
—
ns
148
WR assertion to CAS deassertion
t
CWL
3.25
×
T
C
4.3
28.2
—
ns
149
Data valid to CAS assertion (write)
t
DS
0.5
×
T
C
4.0
1.0
—
ns