AD9741/AD9743/AD9745/AD9746/AD9747

Rev. 0 | Page 21 of 28

SPI REGISTER DESCRIPTIONS

Table 15.

Register

Address

Bit

Name

Description

7

SDIODIR

0, operate SPI in 4-wire mode, SDIO pin operates as an input only

1, operate SPI in 3-wire mode, SDIO pin operates as a bidirectional I/O line

6

LSBFIRST

0, LSBFIRST off, SPI serial data mode is MSB to LSB

1, LSBFIRST on, SPI serial data mode is LSB to MSB

5

SWRESET

0, resume normal operation following software RESET

SPI Control

0x00

1, software RESET; loads default values to all registers (except Register 0x00)

7

DATTYPE

0, DAC input data is twos complement binary format

1, DAC input data is unsigned binary format

6

ONEPORT

0, normal two port input mode

1, optional single port input mode, interleaved data received on Port 1 only

Data Control

0x02

4

INVDCO

1, inverts data clock output signal

7

PD_DCO

1, power down data clock output

5

PD_AUX2

1, power down AUX2 DAC

4

PD_AUX1

1, power down AUX1 DAC

3

PD_BIAS

1, power down reference voltage bias circuit

2

PD_CLK

1, power down DAC clock input circuit

1

PD_DAC2

1, power down DAC2 analog output

Power Down

0x03

0

PD_DAC1

1, power down DAC1 analog output

3:2

DAC1MOD<1:0>

00, selects normal mode, DAC1

01, selects mix mode, DAC1

10, selects return-to-zero mode, DAC1

1:0

DAC2MOD<1:0>

00, selects normal mode, DAC2

01, selects mix mode, DAC2

DAC Mode Select

0x0A

10, selects return-to-zero mode, DAC2

0x0B

7:0

DAC1FSC<7:0>

DAC1 full-scale 10-bit adjustment word

1:0

DAC1FSC<9:8>

0x03FF, sets full-scale current to the maximum value of 31.66 mA

0x01F9, sets full-scale current to the nominal value of 20.0 mA

DAC1 Gain

0x0C

0x0000, sets full-scale current to the minimum value of 8.64 mA

0x0D

7:0

AUXDAC1<7:0>

Auxiliary DAC1 10-bit output current adjustment word

1:0

AUXDAC1<9:8>

0x03FF, sets output current magnitude to 2.0 mA

0x0200, sets output current magnitude to 1.0 mA

0x0000, sets output current magnitude to 0.0 mA

7

AUX1PIN

0, AUX1P output pin is active

1, AUX1N output pin is active

6

AUX1DIR

0, configures AUX1 DAC output to source current

AUX DAC1

0x0E

1, configures AUX1 DAC output to sink current

0x0F

7:0

DAC2FSC<7:0>

DAC2 full-scale 10-bit adjustment word

1:0

DAC2FSC<9:8>

0x03FF, sets full-scale current to the maximum value of 31.66 mA

0x01F9, sets full-scale current to the nominal value of 20.0 mA

DAC2 Gain

0x10

0x0000, sets full-scale current to the minimum value of 8.64 mA

0x11

7:0

AUXDAC2<7:0>

Auxiliary DAC2 10-bit output current adjustment word

0x12

1:0

AUXDAC2<9:8>

0x03FF, sets output current magnitude to 2.0 mA

0x0200, sets output current to 1.0 mA

0x0000, sets output current to 0.0 mA

7

AUX2PIN

0, AUX2P output pin is active

1, AUX2N output pin is active

6

AUX2DIR

0, configures AUX2 DAC output to source current

AUX DAC2

1, configures AUX2 DAC output to sink current