DSP56366 Technical Data, Rev. 3.1
Freescale Semiconductor
3-19
138
Last CAS deassertion to RAS deassertion6
BRW[1:0] = 00
BRW[1:0] = 01
BRW[1:0] = 10
BRW[1:0] = 11
tCRP
2.0
× T
C 6.0
3.5
× T
C 6.0
4.5
× T
C 6.0
6.5
× T
C 6.0
24.4
47.2
62.4
92.8
—
19.0
37.8
50.3
75.3
—
ns
139
CAS deassertion pulse width
tCP
1.25
× T
C 4.0
14.9
—
11.6
—
ns
140
Column address valid to CAS assertion
tASC
TC 4.0
11.2
—
8.5
—
ns
141
CAS assertion to column address not valid
tCAH
1.75
× T
C 4.0
22.5
—
17.9
—
ns
142
Last column address valid to RAS deassertion
tRAL
3
× T
C 4.0
41.5
—
33.5
—
ns
143
WR deassertion to CAS assertion
tRCS
1.25
× T
C 3.8
15.1
—
11.8
—
ns
144
CAS deassertion to WR assertion
tRCH
0.5
× T
C 3.7
3.9
—
2.6
—
ns
145
CAS assertion to WR deassertion
tWCH
1.5
× T
C 4.2
18.5
—
14.6
—
ns
146
WR assertion pulse width
tWP
2.5
× T
C 4.5
33.5
—
26.8
—
ns
147
Last WR assertion to RAS deassertion
tRWL
2.75
× T
C 4.3
33.4
—
26.8
—
ns
148
WR assertion to CAS deassertion
tCWL
2.5
× T
C 4.3
33.6
—
27.0
—
ns
149
Data valid to CAS assertion (write)
tDS
0.25
× T
C 3.7
0.25
× T
C 3.0
0.1
—
0.1
—
ns
150
CAS assertion to data not valid (write)
tDH
1.75
× T
C 4.0
22.5
—
17.9
—
ns
151
WR assertion to CAS assertion
tWCS
TC 4.3
10.9
—
8.2
—
ns
152
Last RD assertion to RAS deassertion
tROH
2.5
× T
C 4.0
33.9
—
27.3
—
ns
153
RD assertion to data valid
tGA
1.75
× T
C 7.5
1.75
× T
C 6.5
—
19.0
—
15.4
ns
154
RD deassertion to data not valid7
tGZ
0.0
—
0.0
—
ns
155
WR assertion to data active
0.75
× T
C 0.3
11.1
—
9.1
—
ns
156
WR deassertion to data high impedance
0.25
× T
C
—3.8
—3.1
ns
1 The number of wait states for Page mode access is specified in the DCR.
2 The refresh period is specified in the DCR.
3 The asynchronous delays specified in the expressions are valid for DSP56366.
4 There are no DRAMs fast enough to fit to two wait states Page mode @ 100MHz (See
Table 3-10
DRAM Page Mode Timings, Two Wait States1, 2, 3, 4 (continued)
No.
Characteristics
Symbol
Expression5
66 MHz
80 MHz
Unit
Min
Max
Min
Max