This version (18 May 2021 09:04) was approved by Sreesha Y M.
Table of Contents
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General 2nd Order with Var Param Lookup Slew
Description
The General (2nd-Order / Lookup) block gives access to a wide variety of 2nd-order IIR (infinite impulse response) filter algorithms. See General 2nd-Order Filters (in Algorithm Information) for details about the algorithms driving these blocks.
The filters available are: Tone Peaking General LP/HP Butterworth LP/HP Bessel LP/HP Chebyshev LP/HP
The block is simply a double-precision biquad filter that has stored a set of coefficients in tables in the DSP. To select curves (lookup), use an Index Lookup Table, a Counter block, or a DC Input block in your design and connect it to the red pin.
Usage
Click the icon button:. The curve is defined using the Tone Control window (shown above).
Enter the number of curves desired in the # Curves field. Enter Boosts, (overall) Gain, and Q in their fields. Enter the desired cutoff or center (peaking filters) frequency in the Frequency fields. Other parameters to enter will vary with filter type.
The variety and range of filters are remarkable, as can be seen from the many examples in the General (2nd-Order / Lookup) topic page.
Targets Supported
| Name | ADSP-214xx | ADSP-215xx/SC5xx | ADAU145x/146x |
|---|---|---|---|
| ————————- | ——————-- | ——————————-- | —————————- |
| Parametric EQ | B/S | B/S | S |
Pins
Input
| Name | Type | Description |
|---|---|---|
| —————————— | —————————— | ———————————————— |
| ControlInput | Control | Filter Index Selection |
| Input0 | Audio | Input to the filter |
Output
| Name | Type | Description |
|---|---|---|
| —————————— | —————————— | ———————————————— |
| Output0 | Audio | The filtered output |
Configurable Parameters
| GUI Parameter Name | Default Value | Range | Function Description |
|---|---|---|---|
| ————————————— | ————————— | ——————————————- | ———————————————————- |
| NumCurves | 4 | 2 to 50 | The number of curves desired from which a particular filter can be selected |
| FilterType | 0 | 0 to 5 | Select the type of filter |
| SubType | 0 | 0 and 1 | The “Sub Type” section is only available for butterworth, chebyshev and bessel filter types. The subtype selects either high or low pass. |
| BoostMax | -10 dB | -20 to +20 dB | Set the maximum value for boost |
| BoostMin | 10 dB | -20 to +20 dB | Set the minimum value for boost |
| FrequencyMax | 100 Hz | 0 to 96kHz | The maximum value of frequency |
| FrequencyMin | 300 Hz | 0 to 96kHz | The minimum value of frequency |
| Gain | -5 dB | -20 to +20 dB | Filter Gain |
| QFactor | 0.707 | 0.01 to 10 | Q factor of the filter |
| Ripple | 0.1 | 0.1 to 5 | Set the Ripple factor for filter. Available only for Chebyshev type |
| NumChannels | 1 | 1 to 20 | Number of input and output channels. Change in this value requires re-compilation |
| SlewPoints | 12 | 5 to 22 | The “Slew Points” control sets how many transition points the algorithm uses to transition from one selected filter curve to another, increasing the number of points will provide smoother transitions. |
DSP Parameters
| Parameter Name | Description | ADSP-214xx/SC5xx/215xx | ADAU145x/146x |
|---|---|---|---|
| ———————————— | —————————————————————————-- | —————————————- | —————————- |
| FilterCoefficientsArray | Filter Coefficient Array consisting of all filter coefficients along with slew rate values | Float | FixPoint8d24 |
| slew_mode | Filter Slew Value | NA | Integer32 |
resources/tools-software/sigmastudiov2/modules/filters/gsowvarparamlookupslew.txt · Last modified: 13 May 2021 14:27 by Sreesha Y M