WM9715L
Production Data
DIGITAL AUDIO (SPDIF) OUTPUT
The WM9715L supports the SPDIF standard using the SPDIF_OUT pin as its output.
Register 3Ah is a read/write register that controls SPDIF functionality and manages bit fields
propagated as channel status (or sub-frame in the V case). With the exception of V, this register
should only be written to when the SPDIF transmitter is disabled (SPDIF bit in register 2Ah is ‘0’).
Once the desired values have been written to this register, the contents should be read back to
ensure that the sample rate in particular is supported, then SPDIF validity bit SPCV in register 2Ah
should be read to ensure the desired configuration is valid. Only then should the SPDIF enable bit in
register 2Ah be set. This ensures that control and status information start up correctly at the
beginning of SPDIF transmission.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
2Ah
10
5:4
SPCV
SPSA
0
SPDIF validity bit (read-only)
SPDIF slot assignment (ADCO = 0)
00: Slots 3, 4
Extended
Audio
01
01: Slots 6, 9
10: Slots 7, 8
11: Slots 10, 11
2
SEN
0
SPDIF output enable
1 = enabled, 0 = disabled
Note: Bit 5 of register 4Ch and bit 5 of register
56h must be ‘0’ before the SPDIF output can
be enabled.
3Ah
15
V
0
Validity bit; ‘0’ indicates frame valid, ‘1’
indicates frame not valid
SPDIF
Control
Register
14
DRS
SPSR
0
Indicates that the WM9715L does not support
double rate SPDIF output (read-only)
13:12
10
Indicates that the WM9715L only supports
48kHz sampling on the SPDIF output (read-
only)
11
10:4
3
L
0
Generation level; programmed as required by
user
CC
0000000
Category code; programmed as required by
user
PRE
COPY
AUDIB
PRO
ADCO
0
0
0
0
0
Pre-emphasis; ‘0’ indicates no pre-emphasis,
‘1’ indicates 50/15us pre-emphasis
2
Copyright; ‘0’ indicates copyright is not
asserted, ‘1’ indicates copyright
1
Non-audio; ‘0’ indicates data is PCM, ‘1’
indicates non-PCM format (e.g. DD or DTS)
0
Professional; ‘0’ indicates consumer, ‘1’
indicates professional
5Ch
4
Source of SPDIF data
Additional
Function
Control
0: SPDIF data comes from SDATAOUT (pin
5), slot selected by SPSA
1: SPDIF data comes from audio ADC
Table 20 SPDIF Output Control
PD Rev 4.0 December 2007
34
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
