wm8580a Wolfson Microelectronics plc, wm8580a Datasheet - Page 62

• Manufacturer Part Number: wm8580a
• Description: Multichannel Codec With S/pdif Transceiver
• Manufacturer: Wolfson Microelectronics plc

WM8580
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Table 56 S/PDIF Transmitter Channel Status Bit Control 1
SPDTXCHAN 1
REGISTER
ADDRESS
R31
1Fh
BIT
5:3
7:6
0
1
2
The WM8580 also transmits the preamble and VUCP bits (Validity, User Data, Channel Status and
Parity bits).
Validity Bit
By default, set to 0 (to indicate valid data) with the following exceptions:
1.
2.
User Data
Set to 0 as User Data configuration is not supported in the WM8580 – if TXSRC=00 (S/PDIF
receiver) User Data is the value recovered from the S/PDIF input stream by the S/PDIF receiver.
Channel Status
The Channel Status bits form a 192 frame –lock - transmitted at one bit per sub-frame. Each sub-
frame forms its own 192-frame block. The WM8580 is a consumer mode device and only the first 40
bits of the block are used. All data transmitted from the WM8580 is stereo, so the channel status
data is duplicated for both channels. The only exception to this is the channel number bits (23:20)
which can be changed to indicate whether the channel is left or right in the stereo image. Bits within
this block can be configured by setting the Channel Status Bit Control registers (see Table 56 to
Table 60). If TXSRC=00 (S/PDIF receiver), the Channel Status bits are transmitted with the same
values recovered by the receiver – unless OVWCHAN is set, in which case they are set by the
S/PDIF transmitter channel status registers.
Parity Bit
This bit maintains even parity for data as a means of basic error detection. It is generated by the
transmitter.
For further details of all channel status bits, refer to IEC-60958-3.
TXSRC=00 (S/PDIF receiver), where Validity is the value recovered from the S/PDIF input
stream by the S/PDIF receiver.
TXVAL_OVWR=1, where Validity is the value set in registers TXVAL_SF0 and TXVAL_SF1.
DEEMPH[2:0]
CHSTMODE
CON/PRO
AUDIO_N
LABEL
CPY_N
[1:0]
CHANNEL
STATUS
BIT
5:3
7:6
0
1
2
DEFAULT
000
00
0
0
0
0 = Consumer Mode
Linear PCM Identification
000 = Data from Audio interface has no pre-
1 = Professional Mode (not supported by
WM8580)
0 = S/PDIF transmitted data is audio PCM.
1 = S/PDIF transmitted data is not audio
PCM.
0 = Transmitted data has copyright asserted.
1 = Transmitted data has no copyright
assertion.
emphasis.
001 = Data from Audio interface has pre-
emphasis.
010 = Reserved (Audio interface has pre-
emphasis).
011 = Reserved (Audio interface has pre-
emphasis).
All other modes are reserved and should not
be used.
00 = Only valid mode for consumer
applications.
DESCRIPTION
PD, Rev 4.7, March 2009
Production Data
62