FIR II IP Core: User Guide

ID 683208
Date 8/14/2023
Document Table of Contents
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3.1. FIR II IP Core Filter Specification

Table 8.  Filter Specification Parameters
Parameter Value Description
Filter Settings
Filter Type Single Rate



Fractional Rate

The type of FIR filter.
Interpolation Factor 1 to 128 The number of extra points to generate between the original samples.
Decimation Factor 1 to 128 The number of data points to remove between the original samples.
Maximum Number of Channels 1–128 The number of unique input channels to process.
Frequency Specification
Clock Frequency (MHz) 1–500 The frequency of the input clock.
Clock Slack Integer The amount of pipelining you can control independently of the clock frequency and therefore independently of the clock to sample rate ratio.
Input Sample Rate (MSPS) Real The sample rate of the incoming data.
Coefficient Options
Coefficient Scaling Auto


The coefficient scaling mode. Select Auto to apply a scaling factor in which the maximum coefficient value equals the maximum possible value for a given number of bits. Select None to read in pre-scaled integer values for the coefficients and disable scaling.
Coefficient Data Type Signed Binary

Signed Fractional Binary

The coefficient input data type. Select Signed Fractional Binary to monitor which bits are preserved and which bits are removed during the filtering process.
Coefficient Bit Width 2–32 The width of the coefficients. The default value is 8 bits.
Coefficient Fractional Bit Width 0–32 The width of the coefficient data input into the filter when you select Signed Fractional Binary as your coefficient data type.
Coefficients Reload Options
Coefficients Reload Turn on this option to allow coefficient reloading, which allows you to change coefficient values during run time. Also, additional input ports are added to the filter.
Base Address Integer The base address of the memory-mapped coefficients.
Read/Write mode Read



The read and write mode that determines the type of address decode to build.
Flow Control
Back Pressure Support Turn on for backpressure support. When you turn on this option, the sink indicates to the source to stop the flow of data when its FIFO buffers are full or when there is congestion on its output port.