wm9704q Wolfson Microelectronics plc, wm9704q Datasheet - Page 16

• Manufacturer Part Number: wm9704q
• Description: 4-channel Surround Sound Codec
• Manufacturer: Wolfson Microelectronics plc

WM9704Q
SLAVE CODEC REGISTER ACCESS DEFINITIONS
WOLFSON MICROELECTRONICS LTD
Table 6 ID Selection
WM9704Q supports the AMAP function whereby selection of an ID will automatically map the data
from the interface onto the PCM DACs.
Table 7 Default Slot to DAC Mappings Based on Codec ID
The above automatic mapping of data to slots is extended when the device is operated in the
alternative modes selectable via the mode pins. In these cases the selection of which data slots are
mapped onto internal DACs or I
Table 8 Slot to DAC and I2S Mapping Based on Mode and Codec ID
Master Codec access is exactly as defined for AC’97. For slave Codec access, the AC’97 Digital
Controller must invalidate the tag bits for Slot 1 and 2 Command Address and Data (Slot 0, bits 14
and 13) and place a non-zero value (01, 10, or 11) into the Codec ID field (Slot 0, bits 1 and 0).
Slave Codecs disregard the Command Address and Command Data (Slot 0, bits 14 and 13) tag bits
when they see a 2-bit Codec ID value (Slot 0, bits 1 and 0) that matches their configuration. In a
sense the Slave Codec ID field functions as an alternative Valid Command Address (for Slave reads
and writes) and Command Data (for Slave writes) tag indicator.
Slave Codecs must monitor the Frame Valid bit, and ignore the frame (regardless of the state of the
Slave Codec ID bits) if it is not valid. AC’97 Digital Controllers should set the frame valid bit for a
frame with a slave register access, even if no other bits in the output tag slot except the Slave Codec
ID bits are set.
Quad (10)
6-channel
CODEC ID
The Codec ID is available to the controller via registers 28h and C3, bits D15 and D14
Rev 2.1
Rev 2.1
MODE
PIN 46 CID1
(00)
(01)
00
01
10
11
Ground
Ground
NC
NC
00 or 01
00 or 01
00 or 01
CODEC
10
11
10
11
10
11
PCM left DAC uses
ID
data from slot no.
AC–LINK FRAME DATA USED FOR DACS
PIN 45 CID0
Ground
Ground
TO FRONT DACS
3
3
7
6
SLOTS MAPPED
NC
NC
2
3 and 4
7 and 8
6 and 9
3 and 4
7 and 8
6 and 9
3 and 4
7 and 8
6 and 9
S outputs is selectable as follows. (Note I
PCM right DAC uses
ID SELECTED
data from slot no.
00
01
10
11
SLOTS MAPPED
TO REAR DACS
Not supported
Not supported
in this mode
in this mode
4
4
8
9
7 and 8
3 and 4
7 and 8
OR SLAVE
COMMENTS
Original definition (master)
Original definition (docking)
Left/right surround channels
Centre/LFE channels
MASTER
Master
Slave
Slave
Slave
Not supported
in this mode
I
DATA TO
2
S D0 PIN
7 and 8
3 and 4
7 and 8
7 and 8
3 and 4
7 and 8
2
S enable bit must be set).
44
PD Rev 2.3 January 2001
Production Data
Not supported
in this mode
I
BITCLK
DATA TO
2
Output
6 and 9
6 and 9
3 and 4
6 and 9
6 and 9
3 and 4
S D1 PIN
Input
Input
Input
48
16