AD5272/AD5274

Data Sheet

Rev. D | Page 22 of 28

Table 13. Write and Read to RDAC and 50-TP memory

DIN

SDO1

Action

0x1C03

0xXXXX

Enable update of wiper position and 50-TP memory contents through digital interface.

0x0500

0x1C03

Write 0x100 to the RDAC register, wiper moves to ¼ full-scale position.

0x0800

0x0500

Prepare data read from RDAC register.

0x0C00

0x100

Stores RDAC register content into 50-TP memory. 16-bit word appears out of SDO, where last 10-bits contain the

contents of the RDAC Register 0x100.

0x1800

0x0C00

Prepare data read of last programmed 50-TP memory monitor location.

0x0000

0xXX19

NOP Instruction 0 sends a 16-bit word out of SDO, where the six LSBs last 6-bits contain the binary address of the last

programmed 50-TP memory location, for example, 0x19 (see Table 16).

0x1419

0x0000

Prepares data read from Memory Location 0x19.

0x2000

0x0100

Prepare data read from the control register. Sends a 16-bit word out of SDO, where the last 10-bits contain the contents

of Memory Location 0x19.

0x0000

0xXXXX

NOP Instruction 0 sends a 16-bit word out of SDO, where the last four bits contain the contents of the control register.

If Bit C3 = 1, fuse program command successful.

Table 14. Control Register Bit Map

DB9

DB8

DB7

DB6

DB5

DB4

DB3

DB2

DB1

DB0

0

0

0

0

0

0

C3

C2

C1

C0

Table 15. Control Register Description

Bit Name

Description

C0

50-TP program enable

0 = 50-TP program disabled (default)

1 = enable device for 50-TP program

C1

RDAC register write protect

0 = wiper position frozen to value in 50-TP memory (default)1

1 = allow update of wiper position through a digital interface

C2

Resistor performance enable

0 = RDAC resistor tolerance calibration enabled (default)

1 = RDAC resistor tolerance calibration disabled

C3

50-TP memory program success bit

0 = fuse program command unsuccessful (default)

1 = fuse program command successful

Table 16. Memory Map

Command Number

Data Byte [DB9:DB8]1

Register Contents

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

5

X

X

X

0

0

0

0

0

0

0

Reserved

X

X

X

0

0

0

0

0

0

1

1st programmed wiper location (0x01)

X

X

X

0

0

0

0

0

1

0

2nd programmed wiper location (0x02)

X

X

X

0

0

0

0

0

1

1

3rd programmed wiper location (0x03)

X

X

X

0

0

0

0

1

0

0

4th programmed wiper location (0x04)

…

…

…

…

…

…

…

…

…

…

…

X

X

X

0

0

0

1

0

1

0

10th programmed wiper location (0xA)

X

X

X

0

0

1

0

1

0

0

20th programmed wiper location (0x14)

X

X

X

0

0

1

1

1

1

0

30th programmed wiper location (0x1E)

X

X

X

0

1

0

1

0

0

0

40th programmed wiper location (0x28)

X

X

X

0

1

1

0

0

1

0

50th programmed wiper location (0x32)