AD1981BL Analog Devices, AD1981BL Datasheet - Page 18

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

AD1981BL
The Extended Audio ID register identifies which extended audio features are supported. A nonzero Extended Audio ID value indicates that one or more of the ex-
tended audio features are supported. All registers not shown, and bits containing an X are assumed to be reserved.
VRAS
SPDIF
DSA[1,0]
AMAP
REVC[1,0]
IDC[1:0]
Reg
No. Name
28h Ext’d Audio ID IDC1 IDC0 X
Variable Rate PCM Audio Support (Read-Only). This bit returns a 1 when Read To indicates that the variable rate
PCM audio is supported.
SPDIF Support (Read-Only). This bit returns a 1 when Read To indicates that the SPDIF transmitter is supported
(IEC958).
This bit is also used to validate that the SPDIF transmitter output is actually enabled. The SPDIF bit is allowed to be
set high only if the SPDIF pin (48) is pulled down at power-up, enabling the codec transmitter logic. If the SPDIF
pin is floating or pulled high at power-up, the transmitter logic is disabled; therefore, this bit returns a low, indicat-
ing that the SPDIF transmitter is not available. This bit must always be read back to verify that the SPDIF transmitter
is actually enabled.
DAC Slot Assignments (Read/Write) (Reset Default = 00).
00 DACs 1, 2 = 3 and 4.
01 DACs 1, 2 = 7 and 8.
10 DACs 1, 2 = 6 and 9.
11 Reserved.
Slot DAC Mappings Based on Codec ID (Read-Only). This bit returns a 1 when read to indicate that slot/DAC
mappings based on the codec ID are supported.
REVC[1,0] = 01 indicates codec is AC ’97 revision 2.2 compliant (Read-Only).
Indicates Codec Configuration (Read-Only).
00 = Primary.
01, 10, 11 = Secondary.
D15
D14
D13 D12 D11
X
REVC1 REVC0 AMAP
Extended Audio ID Register (Index 28h)
D10
D9
–18–
D8
X
D7
X
D6
X
D5
DSA1
D4
DSA0
D3 D2
X
SPDIF X
D1 D0
VRAS X605h
Default
REV. 0