Ac test conditions – Rainbow Electronics DS17487 User Manual
Page 28
DS17485/DS17487
28 of 38
RTC AC TIMING CHARACTERISTICS
Over the operating range (5V)
PARAMETER SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Cycle Time
t
CYC
240 DC ns
Pulse-Width,
RD
/
WR
Low
PW
RWL
120
ns
Pulse-Width,
RD
/
WR
High
PW
RWH
80
ns
Input Rise and Fall Time
t
R
, t
F
30 ns
Chip-Select Setup Time
before
WR
or
RD
t
CS
20 ns
Chip-Select Hold Time
t
CH
0 ns
Read Data Hold Time
t
DHR
10 50 ns
Write Data Hold Time
t
DHW
0 ns
Muxed Address Valid Time to
ALE Fall
t
ASL
20 ns
Muxed Address Hold Time to
ALE fall
t
AHL
10 ns
RD
or
WR
High Setup to
ALE Rise
t
ASD
25 ns
Pulse-Width ALE High
PW
ASH
40
ns
ALE Low Setup to
RD
or
WR
Fall
t
ASED
30
ns
Output Data-Delay Time from
RD
t
DDR
20 120 ns 6
Data Setup Time
t
DSW
30
ns
IRQ
Release from
RD
t
IRD
2
ms
AC TEST CONDITIONS
Output Load: 50pF
Input Pulse Levels: 0V to 3.0V
Timing Measurement Reference Levels
Input:
1.5V
Output:
1.5V
Input Pulse Rise and Fall Times: 5ns