X9428 Xicor, X9428 Datasheet - Page 5

• Manufacturer Part Number: X9428
• Description: Single Digitally Controlled Potentiometer
• Manufacturer: Xicor

X9428
The Increment/Decrement command is different from
the other commands. Once the command is issued
and the X9428 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
Table 1. Instruction Set
Note: (7) 1/0 = data is one or zero
REV 1.1.5 7/8/03
Figure 3. Two-Byte Instruction Sequence
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
Increment/Decrement
Wiper Counter Register
HIGH
) while SDA is HIGH, the selected wiper will
Instruction
SCL
SDA
S
T
A
R
T
0
I
1
1
1
1
1
1
0
3
1
I
0
0
0
1
1
1
0
2
0
I
0
1
1
0
0
1
1
1
1
Instruction Set
A3 A2
I
1
0
1
0
1
0
0
0
1/0 1/0
1/0 1/0
1/0 1/0
1/0 1/0
R
0
0
0
1
0
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R
0
0
0
0
A0
X
0
0
0
0
0
0
0
A
C
K
1
move one resistor segment towards the V
terminal. Similarly, for each SCL clock pulse while SDA
is LOW, the selected wiper will move one resistor
segment towards the V
illustration of the sequence and timing for this
operation are shown in Figures 5 and 6 respectively.
I3
1/0 Enable Increment/decrement of the Wiper Counter
X
0
0
0
0
0
0
0
I2
Read the contents of the Wiper Counter Register
Write new value to the Wiper Counter Register
Read the contents of the Data Register pointed to
by R
Write new value to the Data Register pointed to by
R
Transfer the contents of the Data Register pointed
to by R
Transfer the contents of the Wiper Counter Register
to the Data Register pointed to by R
Register
1
–R
I1
1
0
–R
1
I0
–R
0
0
R1 R0 0
Characteristics subject to change without notice.
to its Wiper Counter Register
Operation
L
/R
0
L
terminal. A detailed
A
C
K
S
T
O
P
1
–R
0
5 of 20
H
/R
H