AI Engine/DSP/Window IO
This block implements the 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 window 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.
- Target input throughput (MSPS)
- Specifies the rate at which data samples should be processed. The default value is 200.
- Specify the number of cascade stages
- When this option is not enabled, the tool will determine the filter configuration that best achieves the specified input sampling rate. When the option is enabled, the 'Number of cascade stages' can be specified (which describes the number of AI Engine processors to split the operation over). However, this allows resources to be traded for higher performance and the specified input sampling rate constraint may not be achieved. The value must be in the range 1 to 9.