REV. 0

AD1980

–17–

Power-Down Control/Status Register (Index 26h)

Reg

No. Name

D15

D14

D13 D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

Default

26h Power-Down

EAPD

PR6

PR5 PR4

PR3

PR2

PR1

PR0

XXXXREF

ANL

DAC ADC NA

Control/Status

The ready bits are read only; writing to REF, ANL, DAC, ADC will have no effect. These bits indicate the status for the AD1980 subsections. If the bit is a 1, then

that subsection is ready. Ready is defined as the subsection able to perform in its nominal state. All registers not shown and bits containing an X are assumed to be reserved.

ADC

ADC Sections Ready to Transmit Data

DAC

DAC Sections Ready to Transmit Data

ANL

Analog Amplifiers, Attenuators and Mixers Ready

REF

PR[6:0]

Codec Power-Down Modes. The first three bits are to be used individually rather than in combination with each

other. PR3 can be used in combination with PR2 or by itself. The mixer and reference cannot be powered down via

PR3 unless the ADCs and DACs are also powered down. Nothing else can be powered up until the reference is up.

PR5 has no effect unless all ADCs, DACs, and the AC-Link are powered down. The reference and the mixer can be

either up or down, but all power-up sequences must be allowed to run to completion before PR5 and PR4 are both set.

In multiple codec systems, the master codec’s PR5 and PR4 bits control the slave codec. PR5 is also effective in the

slave codec if the master’s PR5 bit is clear, but the PR4 bit has no effect except to enable or disable PR5.

EAPD

External Audio Power-Down Control. Controls the state of the EAPD pin.

EAPD = 0 sets the EAPD pin low, enabling an external power amplifier (reset defaults).

EAPD = 1 sets the EAPD pin high, shutting off the external power amplifier.