WM8959
Pre-Production
GENERAL PURPOSE INPUT/OUTPUT
The WM8959 provides a number of versatile GPIO functions to enable features such as mobile TV
support, Wi-Fi voice call recording, button and accessory detection and clock output.
The WM8959 has six multi-purpose pins for these functions.
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•
GPIO1, GPIO3, GPIO4 and GPIO5: Dedicated GPIO pins.
LIN3/GPI7 and RIN3/GPI8: Analogue inputs or button/accessory detect inputs.
The following functions are available on some or all of the GPIO pins.
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•
•
•
•
•
•
•
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Alternative DAC interface (DACDAT, DACLRC, BCLK)
Button detect (latched with programmable de-bounce)
MICBIAS / Accessory current or short circuit detect
Clock output
Temperature sensor output
PLL lock output
Logic '1' and logic '0' output
Interrupt event output
Serial data output (register readback)
The functions available on each of the GPIO pins are identified in Table 36.
GPIO PIN FUNCTION GPIO PINS
GPIO1
GPIO3
GPIO4
GPIO5
GPI7
GPI8
BCLK2
Y
DACLRC2
Y
DACDAT2
Y
Y
Y
Y
Y
Y
Y
Y
Y
Button/Accessory Detect Input
Clock Output
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Temperature OK
PLL Lock
Logic 1 and Logic 0
Interrupt
SDOUT (Readback Data)
Pull-up and Pull-down Available
Table 36 Functions Available on GPIO Pins
The GPIO pins are configured by a combination of register settings described in Table 37 to Table 40
in the following section. The order of precedence for the control of the GPIO pins is as listed below.
1. Pin pull-up or pull-down (GPIOn_PU, GPIOn_PD)
2. Audio Interface and GPIO Tristate (AIF_TRIS)
3. Pin configuration (AIFSEL and GPIO1_ENA)
4. GPIO functionality (GPIOn_SEL)
PP, May 2008, Rev 3.1
72
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
