AS4C256K16FO
®
AC parameters common to all waveforms
Standard
Symbol
t
RC
t
RP
t
RAS
t
CAS
t
RCD
t
RAD
t
RSH(R)
t
CSH
t
CRP
t
ASR
t
RAH
t
T
t
REF
t
CLZ
–25
Parameter
Random read or write cycle time
RAS precharge time
RAS pulse width
CAS pulse width
RAS to CAS delay time
RAS to column address delay time
CAS to RAS hold time (read cycle)
RAS to CAS hold time
CAS to RAS precharge time
Row address setup time
Row address hold time
Transition time (rise and fall)
Refresh period
CAS to output in low Z
Min
45
15
25
4
10
8
7
20
5
0
5
1.5
–
0
Max
–
–
75K
–
17
13
–
–
–
–
–
50
8
–
(V
CC
= 5V ± 10%, GND = 0V, T
a
= 0° C to +70° C)
–30
Min
65
25
30
5
15
10
10
30
5
0
5
1.5
–
0
Max
–
–
75K
–
20
14
–
–
–
–
–
50
8
–
70
25
35
6
16
11
10
35
5
0
6
1.5
–
0
–35
Min
Max
–
–
75K
–
24
17
–
–
–
–
–
50
8
–
85
25
50
10
15
15
10
50
5
0
9
3
–
3
–50
Min
Max
–
–
75K
–
35
25
–
–
–
–
–
50
8
–
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
ns
4,5
3
8
6
7
Notes
Read cycle
Standard
Symbol
t
RAC
t
CAC
t
AA
t
AR(R)
t
RCS
t
RCH
t
RRH
t
RAL
t
CPN
t
OFF
–25
Parameter
Access time from RAS
Access time from CAS
Access time from address
Column add hold from RAS
Read command setup time
Read command hold time to CAS
Read command hold time to RAS
Column address to RAS Lead time
CAS precharge time
Output buffer turn-off time
Min
–
–
–
19
0
0
0
12
4
0
Max
25
7
12
–
–
–
–
–
–
6
(V
CC
= 5V±10%, GND = 0V, T
a
= 0° C to + 70° C)
–30
Min
–
–
–
26
0
0
0
16
3
0
Max
30
10
16
–
–
–
–
–
–
8
Min
–
–
–
28
0
0
0
18
4
0
–35
Max
35
10
18
–
–
–
–
–
–
8
–
–
–
30
0
0
0
25
5
0
–50
Min
Max
50
10
25
–
–
–
–
–
–
8
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
8,10
9
9
Notes
6
6,13
7,13
4/11/01; V.0.9.1
Alliance Semiconductor
P. 4 of 25
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
