x9268us24c7979 Intersil Corporation, x9268us24c7979 Datasheet - Page 11

• Manufacturer Part Number: x9268us24c7979
• Description: Dual Digitally Controlled Xdcp? Potentiometers
• Manufacturer: Intersil Corporation

DEVICE DESCRIPTION
Instructions
Four of the nine instructions are three bytes in length.
These instructions are:
– Read Wiper Counter Register – read the current
– Write Wiper Counter Register – change current
– Read Data Register – read the contents of the
– Write Data Register – write a new value to the
The basic sequence of the three byte instructions is
illustrated in Figure 4. These three-byte instructions
exchange data between the WCR and one of the Data
Registers. A transfer from a Data Register to a WCR is
essentially a write to a static RAM, with the static RAM
controlling the wiper position. The response of the
wiper to this action will be delayed by t
from the WCR (current wiper position), to a Data
Register is a write to nonvolatile memory and takes a
minimum of t
between one of the four potentiometers and one of its
associated registers; or it may occur globally, where
the transfer occurs between all potentiometers and
one associated register
Four instructions require a two-byte sequence to
complete. These instructions transfer data between the
host and the X9268; either between the host and one of
the data registers or directly between the host and the
Wiper Counter Register. These instructions are:
wiper position of the selected potentiometer,
wiper position of the selected potentiometer,
selected Data Register;
selected Data Register.
WR
to complete. The transfer can occur
11
WRL
. A transfer
X9268
– XFR Data Register to Wiper Counter Register –
– XFR Wiper Counter Register to Data Register –
– Global XFR Data Register to Wiper Counter
– Global XFR Wiper Counter Register to Data
INCREMENT/DECREMENT COMMAND
The final command is Increment/Decrement (Figure 5
and 6). The Increment/Decrement command is
different from the other commands. Once the
command is issued and the X9268 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
the selected wiper will move one resistor segment
towards the R
pulse while SDA is LOW, the selected wiper will move
one resistor segment towards the R
See Instruction format for more details.
This transfers the contents of one specified Data
Register to the associated Wiper Counter Register.
This transfers the contents of the specified Wiper
Counter Register to the specified associated Data
Register.
Register – This transfers the contents of all speci-
fied Data Registers to the associated Wiper Counter
Registers.
Register – This transfers the contents of all Wiper
Counter Registers to the specified associated Data
Registers.
H
terminal. Similarly, for each SCL clock
HIGH
) while SDA is HIGH,
L
terminal.
August 29, 2006
FN8172.4