wm9703 ETC-unknow, wm9703 Datasheet - Page 14

• Manufacturer Part Number: wm9703
• Manufacturer: ETC-unknow

WM9703
GAIN CONTROL REGISTER LOCATION VERSUS ID
MASTER/SLAVE ID0/1 SUPPORT
WOLFSON MICROELECTRONICS LTD
Table 5 Gain Control Register Location Versus ID
WM9703 supports operation as either a master or a slave codec. Configuration of the device as
either a master or as a slave, is selected by tying the CID pins CID0 and CID1, pins 45 and 46 on the
package.
Fundamentally, a device identified as a master (ID = 00) produces BITCLK as an output, whereas a
slave (any other ID) must be provided with BITCLK as an input. This has the obvious implication that
if the master device on an AC link is disabled, the slave devices cannot function.
The AC’97 Revision 2.1 specification defines that the CID pins have inverting sense, and are
provided with internal weak pull ups. Therefore, if no connections are made to the CID0/1 pins, then
the pins pull hi and an ID = 00 is selected, i.e. master. External connects to ground will select other
IDs.
Table 6 ID Selection
WM9703 supports the AMAP function whereby selection of an ID will automatically map the data
from the interface onto the PCM DACs. This allows a 6-channel audio system to be built using 3
WM9703 devices, with one device configured as a master (ID 00) and the other two as slaves (ID 10
and 11). (See figure 10). In this case, the main channel DACs will have mapped onto them the data
from the normal, surround, and LFE and centre slots respectively, without any user selection.
Table 7 Default Slot to DAC Mappings Based on Codec ID
Table 8 Slot to DAC and Mapping Based on Codec ID
The codec ID is available to the controller via register 28h, bits D15 and D14
CODEC ID
CODEC ID
PIN46 CID1
00 or 01
Volume
Ground
Ground
Mixer
PGA
DAC
10
11
NC
NC
00
01
10
11
PCM left DAC uses
data from slot No.
SLOTS MAPPED
PIN45 CID0
CODEC ID
TO DACS
Ground
Ground
3 and 4
7 and 8
6 and 9
NC
NC
0x
10
11
0x
10
11
0x
10
11
AC–LINK FRAME DATA
3
3
7
6
USED FOR DACS
SELECTED
PCM right DAC uses
data from slot No.
CONTROL REG
01
10
11
00
ID
18h
72h
02h
38h
36h
4
4
8
9
MASTER OR
SLAVE
Master
Slave
Slave
Slave
COMMENTS
Original definition (master)
Original definition (docking)
Left/right surround channels
Centre/LFE channels
MUTE DEFAULT
Muted (bit-15)
AND with 38h, 7, 15
AND with 36h, 7, 15
Not-muted (bit-15)
Muted (15)
Muted (7 and 15)
Muted (7 and15)
PD Rev 3.4 January 2001
Production Data
BITCLK
Output
Input
Input
Input
14