Template Parameters - 2023.2 English

The following table lists parameters for all the FIR filters.

Note

Note that some parameters are not present on certain variants of FIR where the parameter is not applicable to that variant, e.g.: TP_INTERPOLATE_FACTOR is not present on single-rate FIRs.

Note

TP_RND values may vary between AIE and AIE-ML for the same rounding mechanism. String macro definitions are recommended for convenience and compatibility between devices. For AIE-ML see Parameters Supported by FIR Filters.

Table 51 Parameters Supported by FIR Filters
Parameter Name	Type	Description	Range
TT_DATA	Typename	Data Type	int16, cint16, int32, cint32, float, cfloat
TT_COEFF	Typename	Coefficient type	int16, cint16, int32, cint32, float, cfloat
TP_FIR_LEN	Unsigned int	The number of taps	Min - 4, Max - see Maximum FIR Length
TP_INTERPOLATE_FACTOR	Unsigned int	Ratio of output samples to input samples	1 (default) to 7 (interpolating variants only)
TP_DECIMATE_FACTOR	Unsigned int	Ratio of input samples to output samples	1 (default) to 7 (decimating variants only)
TP_SHIFT	Unsigned int	The number of bits to shift unscaled result down by before output.	0 to 61
TP_RND	Unsigned int	Round mode	`rnd_floor` truncate or floor `rnd_ceil` ceiling `rnd_sym_floor` floor to zero `rnd_sym_ceil` ceil to infinity `rnd_neg_inf` round to negative infinity `rnd_pos_inf` round to positive infinity `rnd_sym_zero` symmetrical to zero `rnd_sym_inf` symmetrical to infinity `rnd_conv_even` convergent to even `rnd_conv_odd` convergent to odd Note: Rounding modes: `rnd_sym_floor` and `rnd_sym_ceil` are only supported on AIE-ML device.
TP_INPUT_WINDOW_VSIZE	Unsigned int	The number of samples processed by the graph in a single iteration run. For windows, defines the size of input window. For streams, it impacts the number of input samples operated on in a single iteration of the kernel.	Must be a multiple of the 256-bits In addition, must by divisible by: `TP_SSR` and `TP_DECIMATE_FACTOR`. No enforced range, but large windows will result in mapper errors due to excessive RAM use, for windowed API implementations.
TP_CASC_LEN	Unsigned int	The number of cascaded kernels to use for this FIR.	1 to 40. Defaults to 1 if not set.
TP_DUAL_IP	Unsigned int	Use dual inputs ports. An additional ‘in2’ input port will appear on the graph when set to 1. Its function depends on API configuration. see Window interface for Filters, Streaming interface for Filters.	Range 0 (single input), 1 (dual input). Defaults to 0 if not set.
TP_USE_COEFF_RELOAD	Unsigned int	Enable reloadable coefficient feature. An additional ‘coeff’ port will appear on the graph. Port dimensions depend on SSR configuration, see Coefficient array for Filters,	0 (no reload), 1 (use reloads). Defaults to 0 if not set.
TP_NUM_OUTPUTS	Unsigned int	Number of FIR output ports An additional ‘out2’ output port will appear on the graph when set to 2. Its function depends on API configuration. see Window interface for Filters, Streaming interface for Filters.	1 to 2 Defaults to 1 if not set.
TP_UPSHIFT_CT	Unsigned int	Center tap coeff form	0 = center tap operates like all other coefficients 1 = center tap coeff is a power of 2 shift. (interpolate half-band only)
TP_API	Unsigned int	I/O interface port type	0 = Window 1 = Stream
TP_SSR	Unsigned int	Parallelism factor. SSR stands for Super Sample Rate and allows for higher throughput For more details, refer to Super Sample Rate.	min=1 Defaults to 1 if not set. Max = limited by resource availability
TP_PARA_INTERP_POLY	Unsigned int	Number of interpolation polyphases that produce output data in parallel. For more details, refer to Super Sample Rate.	min = 1 max = `TP_INTERPOLATE_FACTOR` must be a factor of interpolate factor
TP_PARA_DECI_POLY	Unsigned int	Number of decimation polyphases into which data is split into for parallel computation. For more details, refer to Super Sample Rate.	min = 1 max = `TP_DECIMATE_FACTOR` must be a factor of decimation factor
TP_SAT	Unsigned int	Saturation mode	0: ‘none’ 1: ‘saturate’ 3: ‘symmetric saturate’

For a list of template parameters for each FIR variant, see API Reference Overview.