
SLAS653 – FEBRUARY 2010
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removal event is detected. These sticky flags are set by the event occurrence, and are reset only when
read. This requires polling page 0 / register 44. To avoid polling and the associated overhead, the
TLV320AIC3120 also provides an interrupt feature whereby the events can trigger the INT1 and/or INT2
interrupts. These interrupt events can be routed to one of the digital output pins. See
Section 5.6.4.8 for
details.
The TLV320AIC3120 not only detects a headset insertion event, but also is able to distinguish between
the different headsets inserted, such as stereo headphones or cellular headphones. After the
headset-detection event, the user can read page 0 / register 67, bits D6–D5 to determine the type of
headset inserted.
Table 5-29. Headset-Detection Block Registers
Register
Description
Page 0 / register 67, bit D1
Headset-detection enable/disable
Page 0 / register 67, bits D4–D2
Debounce programmability for headset detection
Page 0 / register 67, bits D1–D0
Debounce programmability for button press
Page 0 / register 44, bit D5
Sticky flag for button-press event
Page 0 / register 44, bit D4
Sticky flag for headset-insertion or -removal event
Page 0/ register 46, bit D5
Status flag for button-press event
Page 0 / register 46, bit D4
Status flag for headset insertion and removal
Page 0 / register 67, bits D6–D5
Flags for type of headset detected
The headset detection block requires AVDD to be powered. The headset detection feature in the
TLV320AIC3120 is achieved with very low power overhead, requiring less than 20 mA of additional current
from the AVDD supply.
5.6.4.8
Interrupts
Some specific events in the TLV320AIC3120, which may require host processor intervention, can be used
to trigger interrupts to the host processor. This avoids polling the status-flag registers continuously. The
TLV320AIC3120 has two defined interrupts, INT1 and INT2, that can be configured by programming
page 0 / register 48 and page 0 / register 49. A user can configure interrupts INT1 and INT2 to be
triggered by one or many events, such as:
Headset detection
Button press
DAC DRC signal exceeding threshold
Noise detected by AGC
Overcurrent condition in headphone drivers/speaker drivers
Data overflow in ADC and DAC processing blocks and filters
DC measurement data available
Each of these INT1 and INT2 interrupts can be routed to output pins GPIO1 or DOUT. These interrupt
signals can either be configured as a single pulse or a series of pulses by programming page 0 /
register 48, bit D0 and page 0 / register 49, bit D0. If the user configures the interrupts as a series of
pulses, the interrupts trigger the start of pulses that stop when the flag registers in page 0 / register 44,
page 0 / register 45, and page 0 / register 50 are read by the user to determine the cause of the interrupt.
5.6.5
Programming DAC Digital Filter Coefficients
The digital filter coefficients must be programmed through the I2C interface. All digital filtering for the DAC
signal path must be loaded into the RAM before the DAC is powered on. (Note that default ALLPASS filter
coefficients for programmable biquads are located in boot ROM. The boot ROM automatically loads the
54
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