x9430 Intersil Corporation, x9430 Datasheet - Page 7

• Manufacturer Part Number: x9430
• Description: Dual Digitally Controlled Potentiometer Xdcp ?with Operational Amplifier
• Manufacturer: Intersil Corporation

X9430 – Preliminary Information
Figure 7. Increment/Decrement Timing
REGISTER OPERATION
Both digitally controlled potentiometers share the serial
interface and share a common architecture. Each
potentiometer is associated with a wiper counter regis-
ter (WCR), and four data registers. Figure 8 illustrates
the control, registers, and system features of the
device.
Figure 8. System Block Diagram
Wiper Counter (WCR) and Analog Control
Registers (ACR)
The X9430 contains two wiper counter registers, one
for each XDCP. The wiper counter register is equivalent
to a serial-in, parallel-out counter with its outputs
decoded to select one of sixty-four switches along its
REV 1.0 6/20/00
SCK
CS
SO
A1
A0
SI
HOLD
WP
Control and
Memory
WCR0
WCR1
V
V
CC
SS
(DR0-DR3)
SCK
Detailed Block Diagram
V
SI
W
INC/DEC CMD Issued
0,1
WCR
0,1
+
–
V
V
V
V
V
V
H (0,1)
L (0,1)
W (0,1)
INV (0,1)
N (0,1)
OUT (0,1)
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resistor array. The contents of the wiper counter register
can be altered in four ways: it may be written directly by
the host via the write WCR instruction (serial load); it
may be written indirectly by transferring the contents of
one of four associated data registers (DR) via the XFR
data register instruction (parallel load); it can be modi-
fied one step at a time by the increment/decrement
instruction (WCR only). Finally, it may be loaded with
the contents of its associated data register zero (R0)
upon power-up.
The wiper counter register is a volatile register; that is,
its contents are lost when the X9430 is powered-down.
Although the registers are automatically loaded with
the value in R0 upon power-up, it should be noted this
may be different from the value present at power-down.
Data Registers (DR)
Each potentiometer has four nonvolatile data registers
(DR). These can be read or written directly by the host
and data can be transferred between any of the four
data registers and the WCR. It should be noted all
operations changing data in one of these registers is a
nonvolatile operation and will take a maximum of 10ms.
If the application does not require storage of multiple set-
tings for the potentiometer, these registers can be used
as regular memory locations that could store system
parameters or user preference data.
V
OUT
t
WRID
Characteristics subject to change without notice.
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