TLV320AIC3109EVM Software
22
SLAU738 – September 2017
Copyright © 2017, Texas Instruments Incorporated
TLV320AIC3109EVM-K
Noise gate functions, such as
Hysteresis
,
Enable Clip stepping
,
Threshold (dB)
,
Signal Detect
Debounce (ms)
, and
Noise Detect Debounce (ms)
are set using the corresponding controls in the
Noise Gate
group box.
4.8
Filters Tab
The TLV320AIC3109-Q1 has an advanced feature set for applying digital filtering to audio signals. This
tab controls all of the filter features of the TLV320AIC3109-Q1. In order to use this tab and have plotting of
filter responses correct, the DAC sample rate must be set correctly. Therefore, the clocks must be set up
correctly in the software following the discussion in
. The
Filters
tab is depicted in
.
Figure 15. Filters Tab
The AIC3104 digital filtering is available to both the ADC and DAC. The ADC has optional high pass
filtering and allows the digital output from the ADC through digital effects filtering before exiting the codec
through the PCM interface. Likewise, the digital audio data can be routed through the digital effects
filtering before passing through the optional de-emphasis filter before the DAC. The digital effects filtering
can only be connected to either the ADC or DAC, not both at the same time.
The Filters tab is divided into several areas. The left side of the tab, is used to select between the DAC or
ADC filters and assist in the selection and calculating the desired filter coefficients. The right hand side of
the tab shows a frequency response plot of the digital effects filter selected and the coefficients that are
programmed into the device. The plots show the magnitude and phase response of each biquad section,
plus the combined responses of the two biquad filters. Note that the plot shows only the responses of the
effect filters, not the combined response of those filter along with the de-emphasis and ADC high-pass
filters.
