wm9703 ETC-unknow, wm9703 Datasheet - Page 15

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

Production Data
CONTROL INTERFACE
AC-LINK DIGITAL SERIAL INTERFACE PROTOCOL
Figure 12 AC’97 Standard Bi-directional Audio Frame
Figure 13 AC-link Audio Output Frame
WOLFSON MICROELECTRONICS LTD
SDATA_OUT
SDATA_OUT
TAG PHASE
SDATA_IN
NUMBER
BIT_CLK
SYNC
SYNC
SLOT
END OF PREVIOUS
AUDIO FRAME
CODEC ID
SLOTREQ 3-12
TAG
TAG
0
FRAME
VALID
12.288MHz
STATUS
TAG PHASE
SLOT(1)
ADDR
CMD
ADR
A digital interface has been provided to control the WM9703 and transfer data to and from it. This
serial interface is compatible with the Intel AC’97.
The main control interface functions are:
The WM9703 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 WM9703 provides support for 18-bit operation.
1
SLOT(2)
(’1’ = TIME SLOT CONTAINS
81.4nS
TIME SLOT ’VALID’ BITS
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 powerdown modes
STATUS
DATA
DATA
VALID PCM DATA)
CMD
2
SLOT(12)
LEFT
LEFT
PCM
PCM
3
’0’
RIGHT
RIGHT
(ID1)
PCM
PCM
4
(ID0)
RSRVD
RSRVD
5
19
SLOT (1)
DATA PHASE
CENTRE
RSRVD
PCM
6
0
L SURR
RSRVD
PCM
19
20.8 S (48kHz)
DATA PHASE
7
SLOT (2)
R SURR
RSRVD
PCM
8
0
19
RSRVD
PCM
LFE
SLOT (3)
9
RSRVD
RSRVD
PCM L
(n+1)
10
0
RSRVD
RSRVD
PCM R
PD Rev 3.4 January 2001
(n+1)
11
19
SLOT (12)
RSRVD
RSRVD
PCM C
(n+1)
WM9703
12
0
15