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IBM025170
IBM025171
256K X 16 MULTIPORT VIDEO RAM
IBM025160
IBM025161
IBM Corporation, 1995. All rights reserved.
Use is further subject to the provisions at the end of this document.
Page 14 of 65
33G0307
SA14-4751-05
Revised 3/98
Read Cycle
Symbol
Parameter
-6H
-60
-70
Units
Notes
Min.
Max.
Min.
Max.
Min.
Max.
t
AA
Access time from column address
—
25
—
30
—
35
ns
2, 3
t
CAC
Access time from CE
—
15
—
15
—
17
ns
1, 2, 3
t
OEA
Access time from TRG
—
15
—
15
—
17
ns
t
OES
Output enable setup (TRG low) before RE high
10
—
10
—
10
—
ns
t
OEZ
Primary output disable from TRG high
0
10
0
15
0
17
ns
t
OFF
Primary output disable from CE
0
10
0
15
0
17
ns
5
t
RAC
Access time from RE
—
60
—
60
—
70
ns
1, 2, 3
t
RAL
Column address to RE high
25
—
30
—
35
—
ns
t
RCH
Read hold time after CE goes high
0
—
0
—
0
—
ns
4
t
RCS
Read command setup time
0
—
0
—
0
—
ns
t
RRH
Read command hold time to RAS high
0
—
0
—
0
—
ns
4
1. Operation within the t
RCD
(max.) limit ensures that t
RAC
(max.) can be met. t
RCD
(max.) is specified as a reference point only: If t
RCD
is greater than the specified t
RCD
(max.) limit, then access time is controlled by t
CAC
.
2. Operation within the t
RAD
(max.) limit ensures that t
RAC
(max.) can be met t
RAD
(max.) is specified as a reference point only: If t
RAD
is greater than the specified t
RAD
(max.) limit, then access time is controlled by t
AA
.
3. Measured with the specified current and 50 pF load for the primary port. Output referenced levels: V
OH
= 2.0V and V
OL
= 0.8V.
4. Either t
RCH
or t
RRH
must be satisfied for a read cycle.
5. t
OFF
(max.) defines the time at which the output achieves the open circuit condition and is not referenced to output voltage levels.
Fast Page Mode Read-Modify-Write-Cycle
Symbol
Parameter
-6H
-60
-70
Units
Notes
Min.
Max.
Min.
Max.
Min.
Max.
t
RWCP
Fast page mode read-modify-write Cycle Time
74
—
74
—
84
—
ns
Page Mode Cycle
Symbol
Parameter
-6H
-60
-70
Units
Notes
Min.
Max.
Min.
Max.
Min.
Max.
t
ACP
Access time from CE precharge
—
28
—
35
—
40
ns
t
HPC
Extended data out cycle time
20
—
25
—
30
—
ns
t
PC
Fast page mode cycle time
30
—
35
—
40
—
ns