AD9943/AD9944

Rev. B | Page 13 of 20

INTERNAL REGISTER MAP

All register values default to 0x000 at power-up except clamp level, which defaults to 128 decimal (AD9943 = 32 LSB clamp level, and

AD9944 = 128 LSB clamp level).

Table 9.

Address Bits

Register Name

A2

A1

A0

Data Bits

Function

Operation

0

0

0

D0

Software Reset (0 = normal operation, 1 = reset all registers to default).

D2, D1

Power-Down Modes (00 = normal power, 01 = standby, 10 = total shutdown).

D3

OB Clamp Disable (0 = clamp on, 1 = clamp off).

D5, D4

Test Mode. Should always be set to 00.

D6

PBLK Blanking Level (0 = blank output to zero, 1 = blank to ob clamp level).

D8, D7

Test Mode 1. Should always be set to 00.

D11 to D9

Test Mode 2. Should always be set to 000.

Control

0

0

1

D0

SHP/SHD Input Polarity (0 = active low, 1 = active high).

D1

DATACLK Input Polarity (0 = active low, 1 = active high).

D2

CLPOB Input Polarity (0 = active low, 1 = active high).

D3

PBLK Input Polarity (0 = active low, 1 = active high).

D4

Three-State Data Outputs (0 = outputs active, 1 = outputs three-stated).

D5

Data Output Latching (0 = latched by DATACLK, 1 = latch is transparent).

D6

Data Output Coding (0 = binary output, 1 = gray code output).

D11 to D7

Test Mode. Should always be set to 00000.

Clamp Level

0

1

0

D7 to D0

OB Clamp Level (AD9943: 0 = 0 LSB, 255 = 63.75 LSB,

AD9944: 0 = 0 LSB, 255 = 255 LSB).

VGA Gain

0

1

1

D9 to D0

VGA Gain (0 = 6 dB, 1023 = 40 dB).