wm8941 Wolfson Microelectronics plc, wm8941 Datasheet - Page 68

• Manufacturer Part Number: wm8941
• Description: Mono Codec With Speaker Driver And Video Buffer
• Manufacturer: Wolfson Microelectronics plc

WM8941
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Figure 41 Example Usage of MODE Pin to Generate a Clock Out in 3-wire Mode
Table 56 Control Interface
This example shows how the MODE_GPIO register bit interfaces to the MODE pad in the case there
MODE is used as a GPIO output. When MODE_GPIO is set, the internal version of MODE is
overridden to high and the MODE pin output driver is enabled. The pull up, which is used to default 3-
wire mode at start-up, is disabled as a power saving measure. MODE_GPIO cannot be set in 2-wire
mode - this would prevent correct operation of the control interface. Internal timing is arranged to
ensure that the override is in place before the pull-up is disabled.
Table 55 Mode is GPIO Control
Auto-incremental writes are supported in 2 wire and 3 wire modes. This is enabled by default.
R8
GPIO
Control
R9
Control
Interface
REGISTER
REGISTER
ADDRESS
ADDRESS
7
1
BIT
BIT
MODE_GPIO
AUTOINC
LABEL
LABEL
0
1
DEFAULT
DEFAULT
Selects MODE pin as a GPIO pin
0 = MODE is an input. MODE selects 2-
wire mode when low and 3-wire mode
when high.
1 = MODE can be an input or output
under the control of the GPIO control
register. Interface operates in 3-wire mode
regardless of what happens on the MODE
pin.
Auto-Incremental write enable
0=Auto-Incremental writes disabled
1=Auto-Incremental writes enabled
DESCRIPTION
DESCRIPTION
PD, Rev 4.0, August 2008
Production Data
68