WM8804
Production Data
w
PD Rev 4.1 September 2007
32
CHANNEL STATUS
The Channel Status bits form a 192-frame block transmitted one bit per sub-frame. Each sub-frame
forms its own 192-frame block. The WM8804 is a consumer mode device and only the first 40 bits of
the block are used. All data transmitted from the WM8804 is stereo, so the channel status data is the
same for both channels. The only exception to this is the channel number bits [23:20] which can be
changed to indicate if the channel is left or right in the stereo image. Bits within this block can be
configured by setting the S/PDIF Transmitter Control registers (see Table 34 to
Table 38). If TXSRC
is set to configure the S/PDIF receiver as the transmit data source, the channel status bits are
transmitted with the same values recovered by the receiver – unless TXSTATSRC is set, in which
case they are set by the S/PDIF Transmitter Control registers.
PARITY BIT
This bit maintains even parity for data as a means of basic error detection. It is generated by the
transmitter.
REGISTER
ADDRESS
BIT LABEL CHANNEL
STATUS
BIT
DEFAULT DESCRIPTION
0 CON/PRO
0
0
Use Of Channel Status Block
0 = Consumer Mode
1 = Professional Mode (not supported by
WM8804).
1 AUDIO_N
1
0
Linear PCM Identification
.
0 = S/PDIF transmitted data is audio PCM.
1 = S/PDIF transmitted data is not audio
PCM.
2 CPY_N
2
0
Copyright Information
0 = Transmitted data has copyright
asserted.
1 = Transmitted data has no copyright
assertion.
5:3 DEEMPH[2:0]
5:3
000
Additional Format Information
000 = Data from Audio interface has no pre-
emphasis.
001 = Data from Audio interface has pre-
emphasis.
All other modes are reserved and should not
be used.
R18
SPDTX1
12h
7:6 CHSTMODE
[1:0]
7:6 00
Channel Status Mode
00 = Only valid mode for consumer
applications.
Table 34 S/PDIF Transmitter Channel Status Bit Control Register 1
REGISTER
ADDRESS
BIT LABEL CHANNEL
STATUS
BIT
DEFAULT DESCRIPTION
R19
SPDTX2
13h
7:0 CATCODE
[7:0]
15:8 00000000
Category Code
Refer to S/PDIF specification (IEC 60958-3)
for full details.
0x00h indicates “general” mode.
Table 35 S/PDIF Transmitter Channel Status Bit Control Register 2
