GMS90C320
OCT. 2000 Ver 1.2
35
AC Characteristics for 50MHz
External Data Memory Characteristics
Advance Information (50MHz)
External Clock Drive
Parameter
Symbol
at 50 MHz Clock
Variable Clock
1/t
C LCL
= 3.5 to 50MHz
Unit
Min.
Max.
Min.
Max.
RD pulse width
t
R LR H
90
-
6t
C LC L
-30
-
ns
WR pulse width
t
W LW H
90
-
6t
C LC L
-30
-
ns
Address hold after ALE
t
LLA X 2
25
-
2t
C LC L
-15
-
ns
RD to valid data in
t
R LD V
-
60
-
5t
C LC L
-40
ns
Data hold after RD
t
R H D X
0
-
0
-
ns
Data float after RD
t
R H D Z
-
28
-
2t
C LC L
-12
ns
ALE to valid data in
t
LLD V
-
120
-
8t
C LC L
-40
ns
Address to valid data in
t
A VD V
-
125
-
9t
C LC L
-55
ns
ALE to WR or RD
t
LLW L
45
75
3t
C LC L
-15
3t
C LC L
+15
ns
Address valid to WR or RD
t
A VW L
50
-
4t
C LC L
-30
-
ns
WR or RD high to ALE high
t
W H LH
5
35
t
C LC L
-15
t
C LC L
+15
ns
Data valid to WR transition
t
Q VW X
5
-
t
C LC L
-15
-
ns
Data setup before WR
t
Q VW H
100
-
7t
C LC L
-40
-
ns
Data hold after WR
t
W H Q X
5
-
t
C LC L
-15
-
ns
Address float after RD
t
R LA Z
-
0
-
0
ns
Parameter
Symbol
Variable Oscillator
(Freq. = 3.5 to 50MHz)
Unit
Min.
Max.
Oscillator period
t
C LC L
20
285.7
ns
High time
t
C H C X
10
t
C LC L
- t
C LC X
ns
Low time
t
C LC X
10
t
C LC L
- t
C H C X
ns
Rise time
t
C LC H
-
10
ns
Fall time
t
C H C L
-
10
ns
