DP7261

© NIDEC COPAL ELECTRONICS CORP.

3

Doc. No. MD-2122 Rev. E

Characteristics subject to change without notice

SERIAL BUS PROTOCOL

The DP7261 supports the SPI bus data transmission

protocol. The synchronous Serial Peripheral Interface

(SPI) helps the DP7261 to interface directly with

many

of

today's

popular

microcontrollers.

The

DP7261 contains an 8-bit instruction register. The

instruction set and the operation codes are detailed in

the instruction set table 3 on page 9.

DEVICE OPERATION

The DP7261 is two resistor arrays integrated with an

SPI serial interface logic, two 8-bit wiper control

registers and eight 8-bit, non-volatile memory data

registers. Each resistor array contains 255 separate

resistive elements connected in series. The physical

ends of each array are equivalent to the fixed

The tap positions between and at the ends of the

series resistors are connected to the output wiper

CS

¯¯¯ going low the first byte will be received. The part

is accessed via the SI pin, with data being clocked in

on the rising edge of SCK. The first byte contains one

of the six op-codes that define the operation to be

performed.

CMOS transistor switch. Only one tap point for each

potentiometer is connected to its wiper terminal at a

time and is determined by the value of the wiper

control register. Data can be read or written to the

wiper control registers or the non-volatile memory

data registers via the SPI bus. Additional instructions

allows data to be transferred between the wiper

control registers and each respective potentiometer's

non-volatile data registers. Also, the device can be

instructed to operate in an "increment/decrement"

mode.