Epson RTC-72421 A Manuel D’Utilisation
RTC - 72421 / 72423
Page - 5
MQ - 162 - 03
Switching characteristics (AC characteristics)
1. When ALE is used
Write mode
( V
DD
=5 V
±
0.5 V, RTC-72421;Ta=
−
10
°
C to +70
°
C, RTC-72423;Ta=
−
40
°
C to +85
°
C )
Item Symbol
Condition
Min.
Max.
Unit
CS1 set-up time
t
SU
(CS1)
1000
Address set-up time before ALE
t
SU
(A-ALE)
50
Address hold time after ALE
th(ALE-A)
50
ALE pulse width
tw(ALE)
80
ALE set-up time before write
t
SU
(ALE-W)
0
Write pulse width
tw(W)
120
ns
ALE set-up time after write
t
SU
(W-ALE)
50
Data input set-up time before write
t
SU
(D-W)
80
Data input hold time after write
th(W-D)
10
CS1 hold time
th(CS1)
1000
Write recovery time
trec(W)
200
Read mode
( V
DD
=5 V
±
0.5 V, RTC-72421;Ta=
−
10
°
C to +70
°
C, RTC-72423;Ta=
−
40
°
C to +85
°
C )
Item Symbol
Condition
Min.
Max.
Unit
CS1 set-up time
t
SU
(CS1) 1000
Address set-up time before ALE
t
SU
(A-ALE)
50
Address hold time after ALE
th(ALE-A)
50
ALE pulse width
tw(ALE)
80
ALE set-up time before read
t
SU
(ALE-R)
0
ns
ALE set-up time after read
t
SU
(R-ALE)
50
Data output transfer time after read
t
PZV
(R-Q) C
L
=150 pF
120
Data output floating transfer time after read
t
PVZ
(R-Q)
0 70
CS1 hold time
th(CS1)
1000
Read recovery time
trec(W)
200
(1) Write mode
VIH2
tsu(CS1)
tsu(A-ALE)
tw(ALE)
th(ALE-A)
tsu(ALE-W)
tw(W)
VIH1
VIL1
VIH1
VIL1
VIH1
VIL1
VIH1
VIH1
VIL1
VIL1
VIH1
VIL1
tsu(W-ALE)
VIH1
VIL1
VIH1
VIL1
tsu(D-W)
th(W-D)
th(CS1)
VIH2
CS1
A0 to A3
CS0
ALE
D0 to D3
WR
(Input)
(2) Read mode
VIH2
tsu(CS1)
tsu(A-ALE)
tw(ALE)
th(ALE-A)
tsu(ALE-R)
VIH1
VIL1
VIH1
VIL1
VIH1
VIL1
VIH1
VIH1
VIL1
VIL1
VIH1
VIL1
tsu(R-ALE)
VIH1
VIL1
VIH1
VIL1
tpzv(R-Q)
)
)
tpvz(R-Q)
th(CS1)
VIH2
CS1
A0 to A3
CS0
ALE
D0 to D3
RD
(Input)