WM9705_06 WOLFSON [Wolfson Microelectronics plc], WM9705_06 Datasheet - Page 23

• Manufacturer Part Number: WM9705_06
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM9705
DATA SLOT MAPPING
AC-LINK DIGITAL SERIAL INTERFACE PROTOCOL
Figure 11 AC’97 Standard Bi-directional Audio Frame
w
TAG PHASE
SDATAOUT
NUMBER
SDATAIN
SLOT
SYNC
CODEC ID
SLOTREQ 3-12
TAG
TAG
0
STATUS
ADDR
CMD
ADR
DAC data and SPDIF data sent to the device, ADC data sent from the device, can be optionally
mapped into alternative slots under control of slot mapping bits located as follows:
Table 4 Data Slot Mapping Control
Default values and functional behavior are further described in the Serial Interface Register Map
description. DAC slot mapping defaults are in Table 2.
A digital interface has been provided to control the WM9705 and transfer data to and from it. This
serial interface is compatible with the Intel AC’97 specification.
The main control interface functions are:
The WM9705 incorporates a 5-pin digital serial interface that links it to the AC’97 controller. AC-
link is a bi-directional, fixed rate, serial PCM digital stream. It handles multiple input and output
audio streams, as well as control register accesses employing a time division multiplexed (TDM)
scheme. The AC-link architecture divides each audio frame into 12 outgoing and 12 incoming
data streams, each with 20-bit sample resolution. With a minimum required DAC and ADC
resolution of 16-bits, AC’97 may also be implemented with 18 or 20-bit DAC/ADC resolution,
given the headroom that the AC-link architecture provides. The WM9705 provides support for 18-
bit audio operation.
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1
DAC data
SPDIF data
ADC data
SLOT MAPPING DATA
Control of analogue gain and signal paths through the mixer
Bi-directional transfer of ADC and DAC words to and from AC’97 controller
Selection of power-down modes
Control of pen digitizer function
Transfer of pen digitizer information and auxiliary conversion results from the codec
STATUS
DATA
DATA
CMD
2
TYPE
LEFT
LEFT
PCM
PCM
3
RIGHT
RIGHT
PCM
PCM
4
RSRVD
RSRVD
5
DSA[1,0]
SPSA[1,0]
ASS[1,0]
CONTROL
BITS
DATA PHASE
RSRVD
RSRVD
6
RSRVD
RSRVD
7
28h
2Ah
5Ch (non-AC’97 feature)
REGISTER LOCATION
RSRVD
RSRVD
8
RSRVD
RSRVD
9
RSRVD
RSRVD
PCM L
(n+1)
10
RSRVD
RSRVD
PCM R
(n+1)
11
PD Rev 4.4 August 2006
RSRVD
RSRVD
PCM C
(n+1)
12
Production Data
23