DP7409 datasheet(9/16 Pages) COPAL

9 / 16 page

DP7409

Doc. No. MD-2010 Rev. K

Characteristics subject to change without notice

WIPER CONTROL AND DATA REGISTERS

Wiper Control Register (WCR)

The DP7409 contains four 6-bit Wiper Control

Registers, one for each potentiometer. The Wiper

Control Register output is decoded to select one of 64

switches along its resistor array. The contents of the

WCR can be altered in four ways: it may be written by

the host via Write Wiper Control Register instruction; it

may be written by transferring the contents of one of

four associated Data Registers via the XFR Data

time by the Increment/decrement instruction (see

Instruction section for more details). Finally, it is

loaded with the content of its data register zero (DR0)

upon power-up.

The Wiper Control Register is a volatile register that

loses its contents when the DP7409 is powered-

down. Although the register is automatically loaded

with the value in DR0 upon power-up, this may be

different from the value present at power-down.

Data Registers (DR)

Each potentiometer has four 6-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

Registers is a non-volatile operation and will take a

maximum of 5ms.

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

The basic sequence of the three byte instructions is

illustrated in Figure 8. These three-byte instructions

exchange data between the WCR and one of the Data

Registers. The WCR controls the position of the wiper.

The response of the wiper to this action will be de-

layed by tWRL. A transfer from the WCR (current wiper

Table 3. Instruction Set

Note: 1/0 = data is one or zero

Instruction Set

Instruction

WCR1/ P1

WCR0/ P0

Operation

Read Wiper Control

0010

1/0

Read the contents of the Wiper Control

Write Wiper Control

0100

1/0

Write new value to the Wiper Control

Read Data Register

0111/0

1/0

Read the contents of the Data Register

pointed to by P1-P0 and R1-R0

Write Data Register

1001/0

1/0

Write new value to the Data Register

pointed to by P1-P0 and R1-R0

XFR Data Register to

Wiper Control Register

1011/0

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

1101/0

1/0

Transfer the contents of the Wiper Control

Gang XFR Data

Registers to Wiper

Control Registers

1/0

Transfer the contents of the Data Registers

pointed to by R1-R0 of all four pots to their

respective Wiper Control Registers

Gang XFR Wiper

Control Registers to

Data Register

1/0

Transfer the contents of both Wiper Control

Registers to their respective data Registers

pointed to by R1-R0 of all four pots

Increment/Decrement

Wiper Control Register

0100

1/0

Enable Increment/decrement of the Control

Latch pointed to by P1-P0

DP7409 датащи(PDF) 9 Page - Copal Electronics

DP7409 датащи(HTML) 9 Page - Copal Electronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

датащи скачать

ссылки URL