March 2007
The LabVIEW Digital Filter Design Toolkit 8.2.1 addresses installation issues with Windows Vista x64 Edition, the 64-bit version, that are present in the Digital Filter Design Toolkit 8.2. If you have the Digital Filter Design Toolkit 8.2 installed, you first must uninstall that version before installing the Digital Filter Design Toolkit 8.2.1.
This file contains information to introduce you to the Digital Filter Design Toolkit. This file also provides you with help resources you can use while working with the toolkit. The file contains the following information that you need to understand.
The Digital Filter Design Toolkit provides a collection of digital filter design tools to supplement the LabVIEW Full or Professional Development System. The Digital Filter Design Toolkit helps you design digital filters without requiring you to have advanced knowledge of digital signal processing or digital filtering techniques. With the Digital Filter Design Toolkit, you can design, analyze, and simulate floating-point and fixed-point digital filters.
Without prior knowledge about programming in LabVIEW, you can use the Digital Filter Design Express VIs to interact graphically with filter specifications to design appropriate digital filters.
The Digital Filter Design Toolkit provides VIs that you can use to design a digital finite impulse response (FIR) or infinite impulse response (IIR) filter, analyze the characteristics of the digital filter, change the implementation structure of the digital filter, and process data with the digital filter. In addition to the floating-point support, the Digital Filter Design Toolkit provides a set of VIs that you can use to create a fixed-point digital filter model, analyze the characteristics of the fixed-point digital filter, simulate the performance of the fixed-point digital filter, and generate fixed-point C code, integer LabVIEW code, or LabVIEW field-programmable gate array (FPGA) code for a specific fixed-point target.
The Digital Filter Design Toolkit provides VIs for multirate digital filter design. You can use the VIs to design and analyze a floating-point single-stage or multistage multirate filter. You then can use the designed multirate filter to process data. The Digital Filter Design Toolkit also provides a set of VIs that you can use to create, analyze, and simulate a fixed-point multirate filter. You can generate LabVIEW FPGA code from the designed fixed-point multirate filter for an NI Reconfigurable I/O (RIO) target.
In addition to graphical tools for digital filter design, the Digital Filter Design Toolkit also provides MathScript functions that LabVIEW MathScript supports. These MathScript functions enable you to design filters in a text-based environment.
To use the Digital Filter Design Toolkit, you must have National Instruments LabVIEW 8.2 or later, Full or Professional Development System, installed on the host computer.
Note: If you want to use the Digital Filter Design Toolkit to generate LabVIEW FPGA code from a fixed-point filter, you must have the National Instruments LabVIEW FPGA Module and NI-RIO software installed with LabVIEW. Ensure that you install the FPGA Module and NI-RIO software before you install the Digital Filter Design Toolkit. If you already have the Digital Filter Design Toolkit installed, uninstall the Digital Filter Design Toolkit before installing the FPGA Module and NI-RIO software.
Complete the following steps to install the Digital Filter Design Toolkit.
Note: If you want to use the Digital Filter Design Toolkit to generate LabVIEW FPGA code from a fixed-point filter, verify that you have the FPGA Module and NI-RIO software installed.
The Digital Filter Design Toolkit 8.2.1 includes bug fixes but does not provide any new features. The Digital Filter Design Toolkit 8.2 incorporates the following new features:
Use the Digital Filter Design MathScript functions to design digital filters with LabVIEW MathScript in a text-based environment.
The Digital Filter Design Toolkit 8.2 improves the usability of the Fixed-Point Tools VIs. These VIs can help you design a fixed-point filter with only a few required inputs. You also can use these VIs to refine the filter design.
The Digital Filter Design Toolkit 8.2 categorizes filter coefficients into two groups: filter coefficients a/k and filter coefficients b/v. These two groups of filter coefficients use different value ranges. This change enables you to quantize the filter coefficients efficiently by using a limited number of bits.
The Digital Filter Design Toolkit 8.2 enhances fixed-point filter code generation and supports more fixed-point filter models, such as those with 32-bit coefficients. You can specify a fixed-point filter model to perform I32xI16 or I32xI32 multiplications, in addition to I16xI16 multiplications. You also can generate a filter block that can process multichannel signals. The Digital Filter Design Toolkit organizes the generated LabVIEW code in LabVIEW project (.lvproj) files so you can integrate the filter into another project.
For LabVIEW FPGA code generation, the Digital Filter Design Toolkit 8.2 improves the mechanism of storing filter coefficients and the internal states of digital filters. The new mechanism stores the internal states of a filter in the memory items of the generated LabVIEW FPGA code. For FIR filters, this mechanism stores the FIR filter coefficients in look-up tables. When processing multichannel signals, the LabVIEW FPGA code can share the filter coefficients and filtering-control logical resources among the multiple channels.
The Digital Filter Design Toolkit 8.2 provides support for the design, analysis, and implementation of rational resampling multirate filters, in addition to decimation and interpolation filters. Rational resampling is useful for interfacing with digital signal processing (DSP) systems that operate at different rates. For example, you can use rational resampling to convert a 48 kHz signal from a professional audio system to a 44.1 kHz signal for an audio CD.
Use the Multirate FIR Design, Multistage Multirate Filter Design, and Multirate CIC Design Express VIs to design multirate FIR filters, multistage multirate filters, and multirate cascaded integrator comb (CIC) filters interactively.
Use the Multirate Fixed-Point Tools VIs to quantize, model, and simulate fixed-point multirate filters.
Use the DFD FXP MRate Code Generator and the DFD FXP NStage MRate Code Generator VIs to generate LabVIEW FPGA code from fixed-point multirate filters. You can generate code for both one-channel and multichannel filtering applications. You also can generate code from both single-stage and multistage multirate filters.
Use the DFD FXP Moving Average Code Generator VI to generate LabVIEW FPGA code from fixed-point moving average (MA) filters. The LabVIEW FPGA code generated from a fixed-point MA filter helps you perform efficient MA filtering on an input signal using few hardware resources.
Use the Utilities VIs to draw transfer function, zero-pole-gain, and difference equations in picture controls.
Use the DFD Save to Text File and the DFD Save MRate to Text File VIs to save filters, including multirate filters, as text files. You can obtain the filter structures, filter orders, and filter coefficients from the text files. You then can copy the filter coefficients from the text files and use the coefficients in other applications.
Use the DFD Load from Text File VI to load a filter from a text file. You cannot use this VI to load a multirate filter.
The Digital Filter Design Toolkit 8.2 provides more than 100 examples that demonstrate how to accomplish certain tasks using the Digital Filter Design VIs and functions. These examples include both getting-started tutorials and in-depth case studies.
In addition to the known issues in the Digital Filter Design Toolkit 8.2, the Digital Filter Design Toolkit 8.2.1 contains the following new known issue:
Refer to the LabVIEW Help, accessible by selecting Help»Search the LabVIEW Help from the pull-down menu in LabVIEW, for information about using the Digital Filter Design Toolkit.
You can access the examples for the Digital Filter Design Toolkit by selecting Help»Find Examples to display the NI Example Finder and then navigating to the Toolkits and Modules»Digital Filter Design folder. You also can click the Find Examples link in the Examples section of the Getting Started window to display the NI Example Finder. You can modify an example VI to fit an application, or you can copy and paste from one or more examples into a VI that you create.
You also can find the examples for the Digital Filter Design Toolkit in the labview\examples\Digital Filter Design directory.
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