WM8580
Production Data
Frame
192
Frame
1
. . . . . . . . .
Subframe 1
Subframe 2
0
3 4
7 8
27 28
31
32 bit
Word
Sync
preamble
Aux
Audio Sample Word
V
U
C
P
Figure 33 S/PDIF Format
S/PDIF TRANSMITTER
The S/PDIF transmitter generates the S/PDIF frames, and outputs on the SPDIFOP pin. The audio
data for the frame can be taken from one of four sources, selectable using the TXSRC register. The
transmitter can be powered down using the SPDIFTXD register bit. The S/PDIF Transmitter can be
bypassed by setting the REAL_THROUGH register control bit. When set, the SPDIFOP pin sources
the output of the S/PDIF input mux.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R30
SPDTXCHAN 0
1Eh
1:0
TXSRC[1:0]
00
S/PDIF Transmitter Data Source
00 = S/PDIF received data (see REAL_THROUGH)
01 = ADC digital output data.
10 = Secondary Audio Interface
11 = Audio Interface received data
Overwrite Channel Status
2
OVWCHAN
0
Only used if TXSRC=00. Overwrites the received channel
status data using data read from S/PDIF transmitter
channel status register
0 = Channel data equal to recovered channel data.
1 = Channel data taken from channel status registers.
S/PDIF Through Mode Control
3
4
REAL_
0
0
THROUGH
0 = SPDIFOP pin sources output of S/PDIF Transmitter
1 = SPDIFOP pins sources output of S/PDIF IN Mux
S/PDIF Transmitter Validity Overwrite Mode
TXVAL_
OVWR
0 = disabled, validity bit is 0 when transmitter sources
ADC, PAIF or SAIF, or is matches the S/PDIF input
validity when S/PDIF transmitter sources S/PDIF receiver.
1 = enabled, validity bit transmitted for subframe 0 is
defined by TXVAL_SF0, validity bit transmitted for
subframe 1 is defined by TXVAL_SF1.
5
6
4
TXVAL_SF0
TXVAL_SF1
SPDIFTXD
0
0
1
Overwrite Mode S/PDIF Transmitter Validity Sub-Frame 0
0 = transmit validity = 0
1 = transmit validity = 1
Overwrite Mode S/PDIF Transmitter Validity Sub-Frame 1
0 = transmit validity = 0
1 = transmit validity = 1
R51
PWRDN 2
33h
S/PDIF Transmitter powerdown
0 = S/PDIF Transmitter enabled
1 = S/PDIF Transmitter disabled
Table 49 S/PDIF Transmitter Control
PD Rev 4.3 August 2007
56
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
