WM8990ECS/RV Wolfson Microelectronics, WM8990ECS/RV Datasheet - Page 113

• Manufacturer Part Number: WM8990ECS/RV
• Description: Audio CODECs Stereo CODEC w.Class AB/D speaker driver
• Manufacturer: Wolfson Microelectronics

Specifications of WM8990ECS/RV

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

w
Production Data
AUDIO INTERFACE OUTPUT AND GPIO TRISTATE
Register bit AIF_TRIS can be used to tristate the audio interface and GPIO pins as described in
Table 60.
All GPIO pins and digital audio interface pins will be tristated by this function, regardless of the state
of other registers which control these pin configurations.
Table 60 Tri-stating the Audio Interface and GPIO Pins
MASTER MODE BCLK, ADCLRC AND DACLRC ENABLE
The main audio interface pins (BCLK, ADCLRC, ADCDAT, DACLRC and DACDAT) and the
alternative DAC interface pins (BCLK2, DACLRC2, DACDAT2) can be independently programmed to
operate in master mode or slave mode using register bits AIF_MSTR1 and AIF_MSTR2.
When the main audio interface is operating in slave mode, the BCLK, ADCLRC and DACLRC clock
outputs to these pins are by default disabled to allow the digital audio source to drive these pins.
Similarly, when the alternative audio interface is operating in slave mode, the BCLK2 and DACLRC2
clock outputs to these pins are by default disabled.
It is also possible to force the ADCLRC, DACLRC or DACLRC2 to be output using register bits
ADCLRC_DIR and DACLRC_DIR, allowing mixed master and slave modes for the ADCs or the
active DAC audio interface. The active audio interface is selected by register bit AIF_SEL. Enabled
clock outputs on the de-selected audio interface will output logic 0.
When ADCLRC is configured as a GPIO pin (ALRCGPIO1=1), the DACLRC pin is used for the ADCs
and the DACs and will only be disabled in master mode when both ADCs and both DACs are
disabled.
The clock generators for the audio interface are enabled according to the control signals shown in
Figure 78.
Figure 78 Clock Output Control
REGISTER
ADDRESS
R9 (09h)
BIT
13
AIF_TRIS
LABEL
DEFAULT
0
Audio Interface and GPIO Tristate
0 = Audio interface and GPIO pins operate normally
1 = Tristate all audio interface and GPIO pins
DESCRIPTION
PD, March 2009, Rev 4.0
WM8990
113