CAT5269

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10

Data Registers (DR)

Each potentiometer has four 8-bit non-volatile Data

Registers. These can be read or written directly by the host.

Data can also be transferred between any of the four Data

Registers and the associated Wiper Control Register. Any

data changes in one of the Data Registers is a non-volatile

operation and will take a maximum of 10 ms.

If the application does not require storage of multiple

settings for the potentiometer, the Data Registers can be used

as standard memory locations for system parameters or user

preference data.

Instructions

Four of the nine instructions are three bytes in length.

These instructions are:



Read Wiper Control Register – read the current

wiper position of the selected potentiometer in the

WCR



Write Wiper Control Register – change current

wiper position in the WCR of the selected

potentiometer



Read Data Register – read the contents of the

selected Data Register



Write Data Register – write a new value to the

selected Data Register

Table 13. INSTRUCTION SET

Instruction

Instruction Set

Operation

I3

I2

I1

I0

R1

R0

WCR1/

P1

WCR0/

P0

Read Wiper Control

Register

1

0

0

1

0

0

1/0

1/0

Read the contents of the Wiper Control Register

pointed to by P1−P0

Write Wiper Control

Register

1

0

1

0

0

0

1/0

1/0

Write new value to the Wiper Control Register

pointed to by P1−P0

Read Data Register

1

0

1

1

1/0

1/0

1/0

1/0

Read the contents of the Data Register pointed

to by P1−P0 and R1−R0

Write Data Register

1

1

0

0

1/0

1/0

1/0

1/0

Write new value to the Data Register pointed to

by P1−P0 and R1−R0

XFR Data Register to

Wiper Control

Register

1

1

0

1

1/0

1/0

1/0

1/0

Transfer the contents of the Data Register

pointed to by P1−P0 and R1−R0 to its

associated Wiper Control Register

XFR Wiper Control

Register to Data

Register

1

1

1

0

1/0

1/0

1/0

1/0

Transfer the contents of the Wiper Control

Register pointed to by P1−P0 to the Data

Register pointed to by R1−R0

Gang XFR Data

Registers to Wiper

Control Registers

0

0

0

1

1/0

1/0

0

0

Transfer the contents of the Data Registers

pointed to by R1−R0 of both pots to their

respective Wiper Control Registers

Gang XFR Wiper

Control Registers to

Data Register

1

0

0

0

1/0

1/0

0

0

Transfer the contents of both Wiper Control

Registers to their respective data Registers

pointed to by R1−R0 of both pots

Increment/Decrement

Wiper Control Register

0

0

1

0

0

0

1/0

1/0

Enable Increment/decrement of the Control

Latch pointed to by P1−P0

NOTE: 1/0 = data is one or zero

The basic sequence of the three byte instructions is

illustrated in Figure 11. These three-byte instructions

exchange data between the WCR and one of the Data

Registers. The WCR controls the position of the wiper. The

A transfer from the WCR (current wiper position), to a Data

Register is a write to non-volatile memory and takes a

between one of the two potentiometers and one of its

associated registers; or the transfer can occur between both

potentiometers and one associated register.

Four instructions require a two-byte sequence to

complete, as illustrated in Figure 10. These instructions

transfer data between the host/processor and the CAT5269;

either between the host and one of the data registers or

directly between the host and the Wiper Control Register.