WM9714L_06 WOLFSON [Wolfson Microelectronics plc], WM9714L_06 Datasheet - Page 53

• Manufacturer Part Number: WM9714L_06
• Description: AC 97 Audio CODEC
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

Pre-Production
DIGITAL AUDIO (SPDIF) OUTPUT
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The WM9714L supports the SPDIF standard. Pins 48 & 12 can be used to output the SPDIF data.
Note that pins 48 & 12 can also be used as GPIO pins. The GE5 & GE8 bits (register 56h, bit 5 & bit
8) select between GPIO and SPDIF functionality for pins 48 & 12 respectively (see “GPIO and
Interrupt control” section).
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.
Table 45 SPDIF Output Control
2Ah
Extended
Audio
3Ah
SPDIF
Control
Register
5Ch
Additional
Function
Control
REGISTER
ADDRESS
10
5:4
2
15
14
13:12
11
10:4
3
2
1
0
4
BIT
SPCV
SPSA
SEN
V
DRS
SPSR
L
CC
PRE
COPY
AUDIB
PRO
ADCO
LABEL
0
01
0
0
0
10
0
0000000
0
0
0
0
0
DEFAULT
SPDIF validity bit (read-only)
SPDIF slot assignment (ADCO = 0)
00: Slots 3, 4
01: Slots 6, 9
10: Slots 7, 8
11: Slots 10, 11
SPDIF output enable
1 = enabled, 0 = disabled
Validity bit; ‘0’ indicates frame valid, ‘1’
indicates frame not valid
Indicates that the WM9714L does not support
double rate SPDIF output (read-only)
Indicates that the WM9714L only supports
48kHz sampling on the SPDIF output (read-
only)
Generation level; programmed as required by
user
Category code; programmed as required by
user
Pre-emphasis; ‘0’ indicates no pre-emphasis,
‘1’ indicates 50/15us pre-emphasis
Copyright; ‘0’ indicates copyright is not
asserted, ‘1’ indicates copyright
Non-audio; ‘0’ indicates data is PCM, ‘1’
indicates non-PCM format (e.g. DD or DTS)
Professional; ‘0’ indicates consumer, ‘1’
indicates professional
Source of SPDIF data
0: SPDIF data comes from SDATAOUT (pin
5), slot selected by SPSA
1: SPDIF data comes from audio ADC
DESCRIPTION
PP Rev 3.0 June 2006
WM9714L
53