AD1981BL Analog Devices, AD1981BL Datasheet - Page 17

• Manufacturer Part Number: AD1981BL
• Description: Low Voltage AC'97 Soundmax Codec
• Manufacturer: Analog Devices

The ready bits are read-only; writing to REF, ANL, DAC, ADC will have no effect. These bits indicate the status for the AD1981BL subsections. If the bit is a 1, 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.
REV. 0
ADC
DAC
ANL
REF
PR [6:0]
EAPD
Power-Down State
ADCs and Input Mux Power-Down
DACs Power-Down
Analog Mixer Power-Down (V
Analog Mixer Power-Down (V
AC-Link Interface Power-Down
Internal Clocks Disabled
ADC and DAC Power-Down
V
Total Power-Down
Headphone Amp Power-In Standby
Reg
No. Name
26h Power-Down Ctrl/Stat
REF
Standby Mode
ADC Sections Ready to Transmit Data.
DAC Sections Ready to Accept Data.
Analog Amplifiers, Attenuators, and Mixers Ready.
Voltage References, V
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.
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 default).
EAPD = 1 sets the EAPD pin high, shutting the external power amplifier off.
D15
EAPD PR6
REF
REF
D14
and V
and V
REF
D13
PR5
REFOUT
REFOUT
Power-Down Control/Status Register (Index 26h)
and V
D12
PR4
On)
Off)
REFOUT
D11
PR3
up to Nominal Level.
PR2 PR1
D10 D9
Set Bits
PR0
PR1
PR1, PR2
PR0, PR1, PR3
PR4
PR0, PR1, PR4, PR5
PR0, PR1
PR0, PR1, PR2, PR4, PR5
PR0, PR1, PR2, PR3, PR4, PR5, PR6
PR6
–17–
D8
PR0 X
D7
D6
X
D5
X
D4
X
D3
REF
D2
ANL
D1
DAC
PR [6:0]
[000 0001]
[000 0010]
[000 0101]
[000 1011]
[001 0000]
[011 0011]
[000 0011]
[011 0111]
[111 1111]
[100 0000]
AD1981BL
D0
ADC
Default
000Xh