WM8720
Production Data
MODES OF OPERATION
Control of the various modes of operation is either by software control over the serial interface, or
by hard-wired pin control. Selection of software or hardware mode is via MODE pin. The following
functions may be controlled either via the serial control interface or by hard wiring of the
appropriate pins.
FUNCTION
SOFTWARE CONTROL
DEFAULT VALUE
HARDWARE CONTROL
BEHAVIOUR
PIN 18: MODE = 0
PIN 18: MODE = 1
OPTIONS
Input audio
data format
Normal format
I2S format
I2S = 0 (default)
I2S = 1
Pin 4, 5: ML/ I2S, MC/IWL =
00 or 01 or 10
Pin 4, 5: ML/I2S, MC/IWL = 11
Pin 4, 5: ML/I2S, MC/IWL = 00
Input word length
16
18
20
24
IW[1:0] = 00 (default)
IW[1:0] = 11
Pin 4, 5: ML/I2S, MC/IWL = 11
(I2S only)
IW[1:0] = 01
Pin 4, 5: ML/I2S, MC/IWL = 01
Pin 4, 5: ML/I2S, MC/IWL = 10
Pin 6: MD/DM = 1
IW[1:0] = 10
De-emphasis selection
Mute
On
Off
DE = 1
DE = 0 (default)
Pin 6: MD/DM = 0
On
Off
MU = 1
Pin 17: MUTE = 1
Pin 17: MUTE = 0
MU = 0 (default)
Power down control
Input LRCIN polarity
WM8720 on
WM8720 off
Available from Pin 1: PWDN
Pin 1: PWDN = 0
Pin 1: PWDN = 1
Lch/Rch = High/low
Lch/Rch = Low/high
LRP = 0 (default)
LRP = 1
Not available in hardware mode,
default value set
Volume control
Lch, Rch individually
Lch, Rch common
ATC = 0; 0dB (default)
ATC = 1
Not available in hardware mode,
default 0dB
Infinite zero detect
On
Off
IZD = 1
Automute function controlled
from MUTE pin
IZD = 0 (default)
Low = not mute
Z = automute enable
High = muted
Operation enable (OPE)
DAC output control
Enabled
Disabled
OPE = 0 (default)
OPE = 1
See Table 11
for all options
Default is PL[3:0] = 1001,
stereo mode
Not available in hardware mode
Table 3 Control Function Summary
HARDWARE CONTROL MODES
When the MODE pin is held high the following hardware modes of operation are available.
MUTE AND AUTOMUTE OPERATION
In both hardware and software modes pin 17 (MUTE) controls selection of mute directly, and can be
used to enable and disable the automute function, or as an output of the automuted signal.
IZD (Register Bit)
AUTOMUTED
(Internal Signal)
10kΩ
MUTE
PIN
SOFTMUTE
(Internal Signal)
MU (Register Bit)
Figure 6 Mute Circuit Operation
PD Rev 4.0 February 2005
10
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
