X9241A
The Increment/Decrement command is different from
the other commands. Once the command is issued and
the X9241A has responded with an acknowledge, the
master can clock the selected wiper up and/or down in
one segment steps; thereby, providing a fine tuning
capability to the host. For each SCL clock pulse (t
HIGH
)
while SDA is HIGH, the selected wiper will move one
Figure 3. Two-Byte Instruction Sequence
SCL
resistor segment towards the V
H
/R
H
terminal. Similarly,
for each SCL clock pulse while SDA is LOW, the
selected wiper will move one resistor segment towards
the V
L
/R
L
terminal. A detailed illustration of the
sequence and timing for this operation are shown in
Figures 5 and 6 respectively.
SDA
S
T
A
R
T
0
1
0
1
A3
A2
A1
A0
A
C
K
I3
I2
I1
I0
P1 P0
R1 R0
A
C
K
S
T
O
P
Figure 4. Three-Byte Instruction Sequence
SCL
SDA
S
T
A
R
T
0
1
0
1
A3 A2 A1 A0 A
C
K
I3
I2
I1 I0
P1 P0 R1 R0
A CM DW D5 D4 D3 D2 D1 D0 A
C
C
K
K
S
T
O
P
Figure 5. Increment/Decrement Instruction Sequence
SCL
SDA
S
T
A
R
T
0
1
0
1
A3 A2 A1 A0
A
C
K
I3
I2
I1
I0
X
X
P1 P0 R1 R0
A
C
K
I
N
C
1
I
N
C
2
I
N
C
n
D
E
C
1
D
E
C
n
S
T
O
P
REV 1.1.13 12/09/02
www.xicor.com
Characteristics subject to change without notice.
5 of 18
XICOR [ XICOR INC. ]
