MP7628
TIMING DIAGRAM READ CYCLE
A/B
R/W
DS1
DS2
H
t
D
BUS (D
N
)
3-state
Data (A)
t
D
3-state
= 40 ns
= 320 ns
= 120 ns
= 200 ns
t
S
t
DSR
(min)
t
NR
t
D
Data (B)
t
S
t
DSR
t
NR
Set up time for BUS, A/B, R/W
Minimum DS = low pulse
Minimum time between DS = low pulses
Data delay time
t
R
= t
DSR
+ t
NR
TIMING DIAGRAM WRITE CYCLE
DATA (D
N
)
A/B
Data (A)
Data (B)
A Select
t
DHLD
H
L
H
t
D
t
S
t
DSW
t
NW
B Select
R/W
DS1
DS2
DAC A OUT
DAC B OUT
Last Data
Last Data
Set up time for BUS, A/B, R/W
Minimum DS = low pulse
Minimum time between DS = low pulses
Data delay time
t
W
= t
DSW
+ t
NW
Data (A)
t
S
+ t
D
Data (B)
= 40 ns
= 200 ns
= 120 ns
= 110 ns
t
S
t
DSW
(min)
t
NW
t
D
MODE SELECTION TABLE
DS1
L
L
H
H
L
L
H
H
L
L
H
L
L
DS2
H
H
L
L
H
H
L
L
L
L
H
L
L
A/B
H
L
H
L
H
L
H
L
H
L
X
H
L
R/W
L
L
L
L
H
H
H
H
L
L
X
H
H
MODE
WRITE
WRITE
WRITE
WRITE
READ
READ
READ
READ
WRITE
WRITE
HOLD
HOLD
HOLD
DAC
A
B
C
D
A
B
C
D
A&C
B&D
A/B/C/D
A/B/C/D
A/B/C/D
L = LOW STATE
H = HIGH STATE
X = DON’T CARE
Rev. 2.00
6
EXAR [ EXAR CORPORATION ]
