AS4C256K16E0
AC parameters common to all waveforms
Std
Symbol Parameter
tRC
Random read or write cycle time
tRP
RAS precharge time
tRAS
RAS pulse width
tCAS
CAS pulse width
tRCD
RAS to CAS delay time
tRAD
RAS to column address delay time
tRSH(R) CAS to RAS hold time (read cycle)
tCSH
RAS to CAS hold time
tCRP
CAS to RAS precharge time
tASR
Row address setup time
tRAH
Row address hold time
tT
Transition time (rise and fall)
tREF
Refresh period
tCLZ
CAS to output in low Z
Shaded areas contain advance information.
Read cycle
Std
Symbol Parameter
tRAC
Access time from RAS
tCAC
Access time from CAS
tAA
Access time from address
tAR(R)
Column add hold from RAS
tRCS
Read command setup time
tRCH
Read command hold time to CAS
tRRH
Read command hold time to RAS
tRAL
Column address to RAS Lead time
tCPN
CAS precharge time
tOFF
Output buffer turn-off time
Shaded areas contain advance information.
®
-30
Min Max
65
–
25
–
30 75K
5
–
15 20
10 14
10
–
30
–
5
–
0
–
5
–
1.5 50
–
8
0
–
-35
Min Max
70
–
25
–
35 75K
6
–
16 24
11 17
10
–
35
–
5
–
0
–
6
–
1.5 50
–
8
0
–
-30
Min Max
–
30
–
10
–
16
26
–
0
–
0
–
0
–
16
–
3
–
0
8
-35
Min Max
–
35
–
10
–
18
28
–
0
–
0
–
0
–
18
–
4
–
0
8
-50
Min Max Unit
85
– ns
25
– ns
50 75K ns
10
– ns
15 35 ns
15 25 ns
10
– ns
50
– ns
5
– ns
0
– ns
9
– ns
3
50 ns
–
8 ms
3
– ns
Notes
6
7
4,5
3
8
-50
Min Max
–
50
–
10
–
25
30
–
0
–
0
–
0
–
25
–
5
–
0
8
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Notes
6
6,13
7,13
9
9
8,10
4/11/01; v.1.1
Alliance Semiconductor
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