Preliminary Technical Data

Rev. PrA 15-Nov-04| Page 19 of 27

Table 8. AD5744/64 Input Register Format

MSB

LSB

DB23

DB22

DB21

DB20

DB19

DB18

DB17

DB16

DB15

DB14

DB13

DB12

DB11

DB10

DB9

DB8

DB7

DB6

DB5

DB4

DB3

DB2

DB1

DB0

R/W

0

REG2

REG1

REG0

A2

A1

A0

DATA

Table 9. Input Register Bit Functions

R/W

Indicates a read from or a write to the addressed register.

REG2, REG1, REG0

Used in association with the address bits to determine if a read or write operation is to the data register, offset

register, gain register, or function register.

REG2

REG1

REG0

Function

0

0

0

Function Register

0

1

0

Data Register

0

1

1

Coarse Gain Register

1

0

0

Fine Gain Register

1

0

1

Offset Register

A2, A1, A0

These bits are used to decode the DAC channels

A2

A1

A0

Channel Address

0

0

0

DAC A

0

0

1

DAC B

0

1

0

DAC C

0

1

1

DAC D

1

0

0

ALL DACs

D15 – D0

Data Bits

FUNCTION REGISTER

The Function Register is addressed by setting the three REG bits to 000. The values written to the address bits and the data bits determine

the function addressed. The Functions available through the function register are shown in Table 10 and

Table 11.

Table 10. Function Register Options

REG2

REG1

REG0

A2

A1

A0

DB15 .. DB6

DB5

DB4

DB3

DB2

DB1

DB0

0

0

0

0

0

0

NOP, Data = Don’t Care

0

0

0

0

0

1

Don’t Care

Local-

Ground-

Offset Adjust

D1

Direction

D1 Value

D0

Direction

D0

Value

SDO

Disable

0

0

0

1

0

0

CLR, Data = Don’t Care

0

0

0

1

0

1

LOAD, Data = Don’t Care