AI Engine/DSP/Stream IO
This block implements the stream-based FIR Asymmetric Decimation filter targeted for AI Engines.
- Input data type/Output data type
- Describes the type of individual data samples input to and output from the filter function. int16, cint16, int32, cint32, float, cfloat.
- Filter coefficients data type
- Describes the type of individual coefficients of
the filter taps. It should be one of int16, cint16, int32,
cint32, float, cfloat and must also satisfy the following
- Complex types are only supported when the Input/Output data type is also complex.
- 32-bit types are only supported when the Input/Output data type is also a 32-bit type.
- Filter coefficients data type must be an integer type if the Input/Output data type is an integer type.
- Filter coefficients data type must be a float type if the Input/Output data type is a float type.
- Specify filter coefficients via input port
- When this option is enabled, the tool allows you to specify filter coefficients via the input port.
- Filter coefficients
- Specifies the asymmetric filter coefficients. The filter length must be in the range 4 to 240 and must be an integer multiple of the decimation factor.
- Decimation factor
- An unsigned integer which describes the decimation factor of the filter. It must be in the range 2 to 7.
- Input frame size (Number of samples)
- Describes the number of samples used as an input to the filter function. The number of values in the output window will be (Input window size/decimation factor). The input window size must be an integer multiple of the decimation factor and the resulting output window size must be a multiple of 256 bits.
- Scale output down by 2^
- Describes the power of 2 shift down applied to the accumulation of FIR terms before output. It must be in the range 0 to 61.
- Rounding mode
- Describes the selection of rounding to be
applied during the shift down stage of processing. The rounding
options are as follows:
- Floor (truncate)
- Round to positive infinity
- Round to negative Infinity
- Round symmetrical to Infinity
- Round symmetrical to zero
- Round convergent to even
- Round convergent to odd
Modes 2 to 7 round to the nearest integer. They differ only in how they round for the value of 0.5.
- Number of cascade stages:
- Specifies the number of cascade stages. The tool will guarantee the same.