UPD43256B Datasheet, PDF (12/24 Pages) NEC – 256K-BIT CMOS STATIC RAM 32K-WORD BY 8-BIT

µPD43256B
Write Cycle (1/2)
Parameter
Symbol
Write cycle time
tWC
CS to end of write
tCW
Address valid to end of write
tAW
Write pulse width
tWP
Data valid to end of write
tDW
Data hold time
tDH
Address setup time
tAS
Write recovery time
tWR
WE to output in high impedance tWHZ
Output active from end of write tOW
VCC ≥ 4.5 V
µPD43256B-70
µPD43256B-85
µPD43256B-A85/A10/A12
µPD43256B-B10/B12/B15
MIN.
MAX.
MIN.
MAX.
70
85
50
70
50
70
55
60
30
35
0
0
0
0
0
0
30
30
10
10
Unit Condition
ns
ns
ns
ns
ns
ns
ns
ns
ns Note
ns
Note See the output load shown in Figure 2 except for µPD43256B-A, 43256B-B.
Remark These AC characteristics are in common regardless of package types and L, LL versions.
Write Cycle (2/2)
Parameter
VCC ≥ 3.0 V
VCC ≥ 2.7 V
Con-
Symbol µPD43256B-A85 µPD43256B-A10 µPD43256B-A12 µPD43256B-B10 µPD43256B-B12 µPD43256B-B15 Unit
dition
MIN. MAX. MIN. MAX. MIN. MAX. MIN. MAX. MIN. MAX. MIN. MAX.
Write cycle time
tWC
85
100
120
100
120
150
ns
CS to end of write
tCW
70
70
90
70
90
100
ns
Address valid to end of write
tAW
70
70
90
70
90
100
ns
Write pulse width
tWP
60
60
80
60
80
90
ns
Data valid to end of write
tDW
60
60
70
60
70
80
ns
Data hold time
tDH
0
0
0
0
0
0
ns
Address setup time
tAS
0
0
0
0
0
0
ns
Write recovery time
tWR
0
0
0
0
0
0
ns
WE to output in high impedance tWHZ
30
35
40
35
40
50 ns Note
Output active from end of write tOW 10
10
10
10
10
10
ns
Note Loading condition is 1TTL + 100 pF.
Remark These AC characteristics are in common regardless of package types and L, LL versions.
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