DS2252T
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AC CHARACTERISTICS—EXPANDED BUS MODE TIMING SPECIFICATIONS
(VCC = 5V ±10%, TA = 0°C to +70°C.)
#
PARAMETER
SYMBOL
MIN
MAX
UNITS
1
Oscillator Frequency
1/tCLK
1.0
16 (-16)
MHz
2
ALE Pulse Width
tALPW
2tCLK - 40
ns
3
Address Valid to ALE Low
tAVALL
tCLK - 40
ns
4
Address Hold After ALE Low
tAVAAV
tCLK - 35
ns
14
RD
Pulse Width
tRDPW
6tCLK - 100
ns
15
WR
Pulse Width
tWRPW
6tCLK - 100
ns
At 12MHz
5tCLK - 165
16
RD
Low to Valid Data In
At 16MHz
tRDLDV
5tCLK - 105
ns
17 Data Hold after RD High
tRDHDV
0
ns
18 Data Float after RD High
tRDHDZ
2tCLK - 70
ns
At 12MHz
8CLK - 150
19 ALE Low to Valid Data In
At 16MHz
tALLVD
8tCLK - 90
ns
At 12MHz
9tCLK - 165
20
Valid Address to Valid Data
In
At 16MHz
tAVDV
9tCLK - 105
ns
21 ALE Low to RD or WR Low
tALLRDL
3tCLK - 50
3tCLK + 50
ns
22 Address Valid to RD or WR Low
tAVRDL
4tCLK - 130
ns
23 Data Valid to WR Going Low
tDVWRL
tCLK - 60
ns
At 12MHz
tDVWRH
7tCLK - 150
24 Data Valid to WR High
At 16MHz
7tCLK - 90
ns
25 Data Valid after WR High
tWRHDV
tCLK - 50
ns
26
RD
Low to Address Float
tRDLAZ
0
ns
27
RD
or WR High to ALE High
tRDHALH
tCLK - 40
tCLK + 50
ns
EXPANDED DATA MEMORY READ CYCLE