Datasheet

C505/C505C/C505A/C505CA
Data Sheet 72 12.00
AC Characteristics (20 MHz, 0.5 Duty Cycle, cont’d)
External Data Memory Characteristics
Parameter Symbol Limit Values Unit
20 MHz clock
0.5 Duty Cycle
Variable Clock
1/CLP = 2 MHz to 20 MHz
min. max. min. max.
RD
pulse width
t
RLRH
120 – 3 CLP - 30 – ns
WR
pulse width
t
WLWH
120 – 3 CLP - 30 – ns
Address hold after ALE
t
LLAX2
35 – CLP - 15 – ns
RD
to valid data in
t
RLDV
– 75 – 5/2 CLP- 50 ns
Data hold after RD
t
RHDX
0 – 0 – ns
Data float after RD
t
RHDZ
– 38 – CLP - 12 ns
ALE to valid data in
t
LLDV
– 150 – 4 CLP - 50 ns
Address to valid data in
t
AVDV
– 150 – 9/2 CLP - 75 ns
ALE to WR
or RD
t
LLWL
60 90 3/2 CLP - 15 3/2 CLP + 15 ns
Address valid to WR
t
AVWL
70 – 2 CLP - 30 – ns
WR
or RD high to ALE high
t
WHLH
10 40 CLP/2 - 15 CLP/2 + 15 ns
Data valid to WR
transition
t
QVWX
5 – CLP/2 - 20 – ns
Data setup before WR
t
QVWH
125 – 7/2 CLP - 50 – ns
Data hold after WR
t
WHQX
5 – CLP/2 - 20 – ns
Address float after RD
t
RLAZ
– 0 – 0ns
External Clock Drive Characteristics
Parameter Symbol Limit Values Unit
Variable Clock
Freq. = 2 MHz to 20 MHz
min. max.
Oscillator period CLP 50 500 ns
High time
TCL
H
15 CLP-TCL
L
ns
Low time TCL
L
15 CLP-TCL
H
ns
Rise time t
R
– 10 ns
Fall time t
F
– 10 ns
Oscillator duty cycle DC 0.5 0.5 –