When ale is fixed at v – Epson RTC-72421 A User Manual
Page 9
RTC - 72421 / 72423
Page - 6
MQ - 162 - 03
2. When ALE is fixed at V
DD
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
CS1 hold time
th(CS1)
1000
Address set-up time before write
t
SU
(A-W)
50
Address hold time after write
th(W-A)
10
ns
Write pulse width
tw(W)
120
Data input set-up time before write
t
SU
(D-W)
80
Data input hold time after write
th(W-D)
10
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
CS1 hold time
th(CS1)
1000
Address set-up time before read
t
SU
(A-R)
50
Address hold time after read
th(R-A)
10
ns
Data output transfer time after read
tpzv(R-Q)
C
L
=150 pF
120
Data output floating transfer time after read
tpvz(R-Q)
0
70
Read recovery time
trec(R)
200
(1) Write mode
VIH2
tsu(CS1)
tsu(A-W)
tw(W)
VIH1
VIL1
VIH1
VIL1
VIH1
VIL1
VIL1
VIH1
th(W-A)
VIH1
VIL1
VIH1
VIL1
tsu(D-W)
th(W-D)
th(CS1)
VIH2
CS1
A0 to A3
CS0
D0 to D3
WR
(Input)
(2) Read mode
VIH2
tsu(CS1)
tsu(A-R)
VIH1
VIL1
VIH1
VIL1
VIH1
VIL1
VIL1
VIH1
th(R-A)
VOH
VOL
VOH
VOL
tpzv(R-Q)
tpvz(R-Q)
th(CS1)
VIH2
CS1
A0 to A3
CS0
D0 to D3
RD
(Output)
(3) Read/write recovery mode
VIH1
VIH1
RD,WR
trec(R/W)