X9258US24Z Intersil, X9258US24Z Datasheet - Page 5

• Manufacturer Part Number: X9258US24Z
• Description: IC XDCP QUAD 256TP 50K 24-SOIC
• Manufacturer: Intersil
• Series: XDCP™r

Specifications of X9258US24Z

• Taps: 256
• Resistance (ohms): 50K
• Number Of Circuits: 4
• Temperature Coefficient: 300 ppm/°C Typical
• Memory Type: Non-Volatile
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Resistance In Ohms: 50K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ACK Polling Sequence
Instruction Structure
The next byte sent to the X9258 contains the instruction and
register pointer information. The four most significant bits are
the instruction. The next four bits point to one of the two
potentiometers and when applicable they point to one of four
associated registers. The format is shown in Figure 2.
COMMAND COMPLETED
NONVOLATILE WRITE
ENTER ACK POLLING
INSTRUCTION
ISSUE SLAVE
OPERATION?
RETURNED?
ADDRESS
FURTHER
PROCEED
START
ISSUE
ISSUE
ACK
SCL
SDA
YES
YES
S
T
A
R
T
NO
0
NO
5
1
0
FIGURE 3. TWO-BYTE INSTRUCTION SEQUENCE
1
ISSUE STOP
ISSUE STOP
PROCEED
A3
A2
A1
A0
X9258
A
C
K
I3
.
The four high order bits define the instruction. The next 2 bits
(R1 and R0) select one of the four registers that is to be
acted upon when a register oriented instruction is issued.
The last bits (P1, P0) select which one of the four
potentiometers is to be affected by the instruction.
Four of the nine instructions end with the transmission of the
instruction byte. The basic sequence is illustrated in
Figure 3. These two-byte instructions exchange data
between the Wiper Counter Register and one of the data
registers. A transfer from a Data Register to a Wiper Counter
Register is essentially a write to a static RAM. The response
of the wiper to this action will be delayed t
from the Wiper Counter Register (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, wherein the
transfer occurs between all of the potentiometers and one of
their associated registers.
Four instructions require a three-byte sequence to complete.
These instructions transfer data between the host and the
X9258; either between the host and one of the data registers
or directly between the host and the Wiper Counter Register.
These instructions are: Read Wiper Counter Register (read
the current wiper position of the selected potentiometer),
Write Wiper Counter Register (change current wiper position
of the selected potentiometer), Read Data Register (read the
contents of the selected nonvolatile register) and Write Data
Register (write a new value to the selected data register).
The sequence of operations is shown in Figure 4.
I2
I1
I3
FIGURE 2. INSTRUCTION BYTE FORMAT
I0
WR
INSTRUCTIONS
I2
to complete. The transfer can occur
R1
I1
R0
P1
I0
P0
REGISTER
R1
SELECT
A
C
K
R0
REGISTER SELECT
WIPER COUNTER
S
T
O
P
WRL
P1
. A transfer
P0
April 14, 2011
FN8168.5