DP7251 datasheet(9/15 Pages) COPAL

9 / 15 page

DP7251

Doc. No. MD-2017 Rev. F

Characteristics subject to change without notice

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

delayed by tWRL. A transfer from the WCR (current

wiper position), to a Data Register is a write to non-

volatile memory and takes a minimum of tWR to

complete. The transfer can occur between one of the

four

potentiometers

and

one

its

associated

registers; or the transfer can occur between all

potentiometers and one associated register.

Four instructions require a two-byte sequence to

complete, as illustrated in Figure 7. These instructions

transfer data between the host/processor and the

DP7251; either between t he host and one of the data

registers or directly between the host and the Wiper

Control Register. These instructions are:

— XFR Data Register to Wiper Control Register

This transfers the contents of one specified Data

— XFR Wiper Control Register to Data Register

This transfers the contents of the specified Wiper

Control Register to the specified associated Data

— Global XFR Data Register to Wiper Control

This transfers the contents of all specified Data

Registers

the

associated

Wiper

Control

Registers.

— Global XFR Wiper Counter Register to Data

This transfers the contents of all Wiper Control

Registers to the specified associated Data Registers.

The final command is Increment/Decrement (Figure 9

and 10). The Increment/Decrement command is

different

from

the

other

commands.

Once

the

command is issued the master can clock the selected

wiper up and/or down in one segment steps; thereby

providing a fine tuning capability to the host. For each

SCK clock pulse (t

HIGH) while SI is HIGH, the selected

wiper will move one resistor segment towards the R

terminal. Similarly, for each SCK clock pulse while SI

is LOW, the selected wiper will move one resistor

segment towards the R

L terminal.

See Instructions format for more detail.

Figure 7. Two-Byte Instruction Sequence

Figure 8. Three-Byte Instruction Sequence

Figure 9. Increment/Decrement Instruction Sequence

INCREMENT/DECREMENT COMMAND

R1 R0 P1

ID3 ID2 ID1 ID0

Device ID

Internal

Instruction

Opcode

Address

Pot/WCR

Address

R1 R0

ID3 ID2 ID1 ID0

Device ID

Internal

Instruction

Opcode

Address

Data

Address

Pot/WCR

Address

WCR[7:0]

Data Register D[7:0]

P1 P0

D6 D5 D4 D3 D2

D1 D0

ID3 ID2 ID1 ID0

Device ID

Internal

Instruction

Opcode

Address

Data

Address

Pot/WCR

Address

010

A1 A0

R0 P1 P0

DP7251 Datasheet(PDF) 9 Page - Copal Electronics

DP7251 Datasheet(HTML) 9 Page - Copal Electronics

Html Pages

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

Datasheet Download

Link URL