AD1980 Analog Devices, AD1980 Datasheet - Page 19

• Manufacturer Part Number: AD1980
• Description: AD1980 AC'97 SoundMAX® Codec W/spdif W/eq
• Manufacturer: Analog Devices

The extended audio status and control register is a read/write register that provides status and control of the extended audio features. All registers not shown and bits
containing an X are assumed to be reserved.
EVRA
EDRA
ESPDIF
SPSA[1,0]
ECDAC
ESDAC
ELDAC
SPCV
PRI
PRJ
PRK
VFORCE
REV. 0
Reg
No. Name
2Ah Extended Audio VFORCE X
Stat/Ctrl
SPDIF Slot Assignment Bits (Read/Write).
Variable Rate Audio (Read/Write).
VRA = 0, sets fixed sample rate audio at 48 kHz (Reset Default).
VRA = 1, enables variable rate audio mode (enables sample rate registers and SLOTREQ signaling).
Double Rate Audio.
DRA = 1 enables double rate audio mode in which data from PCM L and PCM R in output slots 3 and 4 is used in
conjunction with PCM L (n + 1) and PCM R (n + 1) data to provide DAC streams at twice the sample rate desig-
nated by the PCM front sample rate control register. When using the double rate audio only the front DACs are
supported, and all other DACs (surround, center, and LFE) are automatically powered down.
Note that DRA can be used without VRA; in that case the converter rates are forced to 96 kHz if DRA = 1.
SPDIF Transmitter Subsystem Enable/Disable Bit (Read/Write).
SPDIF = 1 enables the SPDIF transmitter.
SPDIF = 0 disables the SPDIF transmitter (default).
These bits control the SPDIF slot assignment and respective defaults, depending on the codec ID configuration.
See the following table.
Center DAC Status (Read Only).
CDAC = 1 indicates the PCM center DAC is ready.
Surround DAC status (Read Only).
SDAC = 1 indicates the PCM surround DACs are ready.
LFE DAC status (Read Only).
LDAC = 1 indicates the PCM LFE DAC is ready.
SPDIF Configuration Valid (Read Only). Indicates the status of the SPDIF transmitter subsystem, enabling the
driver to determine if the currently programmed SPDIF configuration is supported. SPCV is always valid, indepen-
dent of the SPDIF enable bit status.
SPCV = 0 indicates current SPDIF configuration (SPSA, SPSR, DAC slot rate, DRS) is not valid (not supported).
SPCV = 1 indicates current SPDIF configuration (SPSA, SPSR, DAC slot rate, DRS) is valid (supported).
Center DAC Power-Down (Read/Write).
PRJ = 1 turns off the PCM Center DAC.
Surround DACs Power-Down (Read/Write).
PRJ = 1 turns off the PCM surround DACs.
LFE DAC Power-Down (Read/Write).
PRJ = 1 turns off the PCM LFE DAC.
Validity Force Bit (Reset Default = 0).
When asserted, this bit forces the SPDIF stream validity flag (Bit 28 within each SPDIF L/R subframe) to be con-
trolled by the V bit (D15) in Register 3Ah (SPDIF control register).
VFORCE = 0 and V = 0; the Validity Bit is managed by the codec error detection logic.
VFORCE = 0 and V = 1; the Validity Bit is forced high, indicating subframe data is invalid.
VFORCE = 1 and V = 0; the Validity Bit is forced low, indicating subframe data is valid.
VFORCE = 1 and V = 1; the Validity Bit is forced high, indicating subframe data is invalid.
D15
D14 D13 D12 D11 D10
PRK PRJ PRI SPCV X
Extended Audio Status and Control Register (Index 2Ah)
D9 D8
ELDAC ESDAC ECDAC SPSA1 SPSA0 X
–19–
D7
D6
D5
D4
D3 D2
ESPDIF EDRA EVRA 0XX0h
D1
AD1980
D0
Default