Production Data

WM2608

WOLFSON MICROELECTRONICS LTD

PD Rev 1.0 April 2001

11

DAC A TO H CODE REGISTERS

Addresses 0 to 7 are the DAC registers. Bits D11 (MSB) to D2 (LSB) from these registers are

transferred to the respective DAC when the LOADB input (pin 18) is low. Bits D1 and D0 are ignored.

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

D8D7D6D5

D4

D3

D2

D1

D0

Function

X

X

XXXX

X

PD

DO

X

X

IM

Default

X

X

XXXX

X

0

0000

Table 5 Control Register 0 Map

BIT

DESCRIPTION

0

1

PD

Full device Power Down

Normal

Power Down

DO

DOUT Enable

Disabled

Enabled

IM

Input Mode

Straight Binary

Two’s Complement

X

Reserved

Table 6 Control Register 0 Functionality

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

3

µs and power consumption is reduced.

BIT

D11

D10

D9

D8D7D6D5

D4

D3

D2

D1

D0

Function

X

X

X

X

Default

X

X

X

X

0

0

0

0

0

0

0

0

Table 7 Control Register 1 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 Control Register 1 Functionality

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 value of 1023 to address 12 will set DAC A to full scale and DAC B to zero scale.