Production Data

WM2630

WOLFSON MICROELECTRONICS LTD

PD Rev 1.1 February 2001

11

DAC A TO H CODE REGISTERS

Addresses 0 to 7 are the DAC registers. The data written to these registers is transferred to the

respective DAC when the LOADB input (pin 18) is low. For instantaneous updating, LOADB can be held

low permanently.

CONTROL REGISTER 0

Control register 0 (address 8) is used to select functions that apply to the whole IC, such as Power Down

and Data Input Format.

BIT

D11

D10

D9

D8

D7

D6

D5

D4D3D2D1D0

Function

X

X

XX

XX

X

PD

DO

R1

R0

IM

Default

X

X

X

X

X

X

X

00000

Table 5 Register Map

BIT

DESCRIPTION

0

1

PD

Full device Power Down

Normal

Power Down

DO

DOUT Enable

Disabled

Enabled

R1

Int / Ext Reference Select

External

Internal

R0

Internal Reference Select

1.024V

2.048V

IM

Input Mode

Straight Binary

Two’s Complement

X

Reserved

Table 6 Register Map

CONTROL REGISTER 1

Control register 1 (address 9) is used to power down individual pairs of DACs and select their settling

time. Powering down a pair of DACs disables their amplifiers and reduces the power consumption of the

device. The settling time in fast mode is typically 1

µs. In slow mode, the settling time is typically 3µs and

power consumption is reduced.

BIT

D11

D10

D9

D8

D7

D6

D5

D4D3D2D1D0

Function

X

X

X

X

Default

X

X

X

X

0

0

0

0000

0

Table 7 Register Map

BIT

DESCRIPTION

0

1

Power Down DACs X and Y

Normal

Power Down

Speed Setting for DACs X and Y

Slow

Fast

Table 8 Register Map

DAC PRESET REGISTER

The Preset register (address 10) makes it possible to update all eight DACs at the same time. The value

stored in this register becomes the digital input to all the DACs when the asynchronous PREB input (pin

5) is driven low. If no data has previously been written to the preset register, all DACs are set to zero

scale.

TWO-CHANNEL REGISTERS

The two-channel registers (addresses 12 to 15) provide a ‘differential output’ function where writing data

to one DAC will automatically write the complement to the other DAC in the pair. For example, writing a

hexadecimal value of FFFF to address 12 will set DAC A to full scale and DAC B to zero scale.