X9418 Xicor, X9418 Datasheet - Page 5

• Manufacturer Part Number: X9418
• Description: Dual Digitally Controlled Potentiometers
• Manufacturer: Xicor

The Increment/Decrement command is different from
the other commands. Once the command is issued and
the X9418 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
while SDA is HIGH, the selected wiper will move one
Table 1. Instruction Set
Note: (7) 1/0 = data is one or zero
X9418
Figure 3. Two-Byte Instruction Sequence
REV 1.1.5 7/23/02
Read Wiper Counter
Register
Write Wiper Counter
Register
Read Data Register
Write Data Register
XFR Data Register to
Wiper Counter Register
XFR Wiper Counter
Register to Data Register
Global XFR Data
Registers to Wiper
Counter Registers
Global XFR Wiper
Counter Registers to
Data Register
Increment/Decrement
Wiper Counter Register
Instruction
SCL
SDA
S
T
A
R
T
0
I
1
1
1
1
1
1
0
1
0
3
1
I
0
0
0
1
1
1
0
0
0
2
0
I
0
1
1
0
0
1
0
0
1
1
1
Instruction Set
A3 A2 A1 A0
I
1
0
1
0
1
0
1
0
0
0
1/0 1/0
1/0 1/0
1/0 1/0
1/0 1/0
1/0 1/0
1/0 1/0
R
0
0
0
1
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HIGH
R
0
0
0
0
)
P
0
0
0
0
0
0
0
0
0
A
C
K
1
resistor segment towards the V
for each SCL clock pulse while SDA is LOW, the
selected wiper will move one resistor segment towards
the V
sequence and timing for this operation are shown in
Figures 5 and 6 respectively.
I3
1/0 Read the contents of the Wiper Counter Register
1/0 Write new value to the Wiper Counter Register
1/0 Read the contents of the Data Register pointed to
1/0 Write new value to the Data Register pointed to by
1/0 Transfer the contents of the Data Register pointed
1/0 Transfer the contents of the Wiper Counter Register
1/0 Enable Increment/decrement of the Wiper Counter
P
0
0
0
I2
pointed to by P
pointed to by P
by P
P
to by P
Register
pointed to by P
R
Transfer the contents of the Data Registers pointed
to by R
Counter Registers
Transfer the contents of both Wiper Counter
Registers to their respective data Registers pointed
to by R
Register pointed to by P
L
/R
0
1
–R
and R
L
I1
0
0
and R
terminal. A detailed illustration of the
0
1
1
I0
–R
–R
and R
1
–R
0
0
R1 R0 0
1
of both pots to their respective Wiper
of both pots
Characteristics subject to change without notice.
0
–R
1
0
0
0
–R
0
to the Data Register pointed to by
0
Operation
to its associated Wiper Counter
0
P0
H
/R
A
C
K
H
terminal. Similarly,
S
T
O
P
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