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 × TC 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 tGZ.
Table 3-11
DRAM Page Mode Timings, Three Wait States1, 2, 3
No.
Characteristics
Symbol
Expression4
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
tPC
2
× T
C
1.25
× T
C
40.0
35.0
—
ns
132 CAS assertion to data valid (read)
tCAC
2
× T
C 7.0
—
13.0
ns
133 Column address valid to data valid (read)
tAA
3
× T
C 7.0
—
23.0
ns
134 CAS deassertion to data not valid (read hold time)
tOFF
0.0
—
ns
135 Last CAS assertion to RAS deassertion
tRSH
2.5
× T
C 4.0
21.0
—
ns
136 Previous CAS deassertion to RAS deassertion
tRHCP
4.5
× T
C 4.0
41.0
—
ns
137 CAS assertion pulse width
tCAS
2
× T
C 4.0
16.0
—
ns
138 Last CAS deassertion to RAS assertion5
BRW[1:0] = 00
BRW[1:0] = 01
BRW[1:0] = 10
BRW[1:0] = 11
tCRP
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
tCP
1.5
× T
C 4.0
11.0
—
ns
140 Column address valid to CAS assertion
tASC
TC 4.0
6.0
—
ns
141 CAS assertion to column address not valid
tCAH
2.5
× T
C 4.0
21.0
—
ns
142 Last column address valid to RAS deassertion
tRAL
4
× T
C 4.0
36.0
—
ns
143 WR deassertion to CAS assertion
tRCS
1.25
× T
C 4.0
8.5
—
ns
144 CAS deassertion to WR assertion
tRCH
0.75
× T
C 4.0
3.5
—
ns
145 CAS assertion to WR deassertion
tWCH
2.25
× T
C 4.2
18.3
—
ns
146 WR assertion pulse width
tWP
3.5
× T
C 4.5
30.5
—
ns
147 Last WR assertion to RAS deassertion
tRWL
3.75
× T
C 4.3
33.2
—
ns
148 WR assertion to CAS deassertion
tCWL
3.25
× T
C 4.3
28.2
—
ns
149 Data valid to CAS assertion (write)
tDS
0.5
× T
C 4.0
1.0
—
ns