FIR Struct Parameters - 2021.2 English

Vitis High-Level Synthesis User Guide (UG1399)

Document ID
English (United States)
Release Date
2021.2 English
Table 1. FIR Struct Parameters
Parameter Description
input_width Data input port width
input_fractional_bits Number of fractional bits on the input port
output_width Data output port width
output_fractional_bits Number of fractional bits on the output port
coeff_width Bit-width of the coefficients
coeff_fractional_bits Number of fractional bits in the coefficients
num_coeffs Number of coefficients
coeff_sets Number of coefficient sets
input_length Number of samples in the input data
output_length Number of samples in the output data
num_channels Specify the number of channels of data to process
total_num_coeff Total number of coefficients
coeff_vec[total_num_coeff] The coefficient array
filter_type The type implementation used for the filter
rate_change Specifies integer or fractional rate changes
interp_rate The interpolation rate
decim_rate The decimation rate
zero_pack_factor Number of zero coefficients used in interpolation
rate_specification Specify the rate as frequency or period
hardware_oversampling_rate Specify the rate of over-sampling
sample_period The hardware oversample period
sample_frequency The hardware oversample frequency
quantization The quantization method to be used
best_precision Enable or disable the best precision
coeff_structure The type of coefficient structure to be used
output_rounding_mode Type of rounding used on the output
filter_arch Selects a systolic or transposed architecture
optimization_goal Specify a speed or area goal for optimization
inter_column_pipe_length The pipeline length required between DSP columns
column_config Specifies the number of DSP module columns
config_method Specifies how the DSP module columns are configured
coeff_padding Number of zero padding added to the front of the filter

When specifying parameter values that are not integer or boolean, the HLS FIR namespace should be used.

For example the possible values for rate_change are shown in the following table to be integer and fixed_fractional. The values used in the C program should be rate_change = hls::ip_fir::integer and rate_change = hls::ip_fir::fixed_fractional.