Frequency Devices SPPDM-01 User Manual

SPPDF 01 Development Suite

User’s Manual

For SPPDM-01 FIR Filter Platform

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SPPDF 01 Development Suite

User’s Manual

Table of Contents

Chapter I - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page

1.1. Hardware Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2. Software Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Chapter II - Filter Coefficient Generator

2.1. Filter Coefficient Generator Installation and Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.2. Filter Coefficient Generator GUI Control Group Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Chapter III – Filter Coefficient Loader

3.1. Filter Coefficient Loader Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

3.2. Filter Coefficient Loader Installation and Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

3.3. Filter Coefficient Loader GUI Main Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Appendix

A. Example 1 -- Manual FIR Filter Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Example 2 – Filter Coefficient Generator, Immediate Mode Operation

Single Set Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Example 3 - Filter Coefficient Generator, Immediate Mode Operation

Multiple Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Example 4 – Filter Coefficient Loader, Batch Mode Operation

Single Set Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Example 5 – Filter Coefficient Loader, Batch Mode Operation

Multiple Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

B. Software Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

C. Field Programming Circuit for SPPDM-01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

List of Figures

1. SPPDF-01 Hardware Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2. Filter Coefficient Generator Main Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3. Filter Coefficient Loader GUI Main Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

4. Filter Coefficient Generator Display – Immediate Mode Operation,

Single Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

5. Amplitude/Phase Plot – Immediate Mode Operation,

Single Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

6. Filter Coefficient Generator Display – Immediate Mode Operation,

Multiple Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

7. Amplitude/Phase plot – Immediate Mode Operation,

Multiple Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

8. Filter Coefficient Loader – Batch Mode Operation,

Single Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

9. Filter Coefficient Loader – Batch Mode Operation,

Multiple Coefficient Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

10. Required circuit to provide coefficient memory access

for the SPPDM-01 family of products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

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SPPDF-01 Development Suite

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Introduction

Chapter I

3

The SPPDF-01 is a FIR Filter Design Suite for the SPPDM-01 dual channel, FIR filter plat-

form with analog I/O that utilizes Frequency Devices MatLab

TM

GUI with MatLabTMV5.3 or

MatLab

TM

V6.0.

The SPPDF-01 Suite consists of:

• An SPPDM-01 dual channel signal processing platform containing a MatLabTMcompatible

FIR filter algorithm

• An SPPDB-01 development board for the SPPDM-01,

• An RS232, DB9 cable, and

• A CDRom with CDDF-01 software containing this manual, data sheets for the SPPDF-01,

SPPDM-01 and SPPDB-01, and the following utilities:

1. Filter Coefficient Generator (FCG) Software – This FCG software provides coeffi-

cient data conversion for FIR filters in the frequency domain and generates sets of
coefficients for single or multiple filters between 100 Hz and 20.0 kHz. From a set of
specifications, FCG produces a data set that approximates the given filter characteris­tics in the frequency domain. The FCG software is a tool compatible with MatLab

TM

V5.3 or MatLabTMV6.0 and allows the user to evaluate and modify low-pass, high­pass, band-pass, and band-reject filters.

2. Filter Coefficient Loader (FCL) Software – FCL software is the communication and

translation interface that loads single or multiple sets of coefficients for various FIR fil­ter types into the SPPDM-01 platform’s flash memory implementing the direct applica­tion, physical realization, and usage of the FIR filters. Coefficient loading utilizes the
RS232 interface on the SPPDB-01 development board to communicate with MatLab

TM

V5.3 or MatLabTMV6.0 FIR filter coefficient library files

Appendix C of this manual has information on how to add field programming capabili­ty. A circuit diagram is provided that may be added to the field application of the SPPDM-01

which emulates the SPPDB-01 development board and permits field loading of new filter
coefficient sets.

1.1 Hardware Description

The SPPDM-01 has a double precision FIR filter algorithm programmed into its EEPROM that
provides two channels of FIR filtering. Each channel is independently programmed and the FIR
algorithm can be configured, shaped or altered in terms of; corner frequency, number of taps
(shape factor) and filter type simply by loading different sets of coefficients. The FIR filter data
comes from a dual 24-bit sigma-delta ADC on the SPPDM-01. This 24-bit data is left-shifted to
automatically become a 32-bit double word. The on-board DSP reads a 32-bit coefficient set
from Flash Memory for each channel according to the user’s selection. Finally, the digital output
of the DSP is filtered and fed sequentially into a dual 24-bit DAC for conversion of the now fil­tered analog signals. The 2 Megabits Flash Memory permits many coefficient sets to be stored
and user addressed for maximum flexibility.

Many FIR filter types can be implemented with the DSP algorithm, provided the MatLab

TM

utili-

ty converges mathematically and the user stays within the 100 Hz to 20.0 kHz frequency range.
The number of filter channel taps for each filter channel must be ≤300.

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SPPDF-01 Development Suite

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Introduction

Chapter I

See Figure 1 for SPPDF-01 hardware configuration:

Figure 1 - SPPDF-01 Hardware Configuration

An oscilloscope is recommended for troubleshooting and a network analyzer is presented

as an example of a frequency-magnitude, frequency-phase signal characteristic analyzer.

4

DB9

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SPPDF-01 Development Suite

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Introduction

Chapter I

1.2 Software Description

Users can define and configure filters using FREQUENCY DEVICES’ SPPDF-01 Filter

Coefficient Generator (FCG) software. The FCG - GUI is invoked from within the MatLab

TM

(User Supplied) environment and sends commands to the MatLabTMengine using the specific fil­ter values loaded into the FCG – GUI. The MatLab

TM

engine responds to FCG commands and
calculates coefficient sets for the indicated FIR filters. These coefficient sets are temporarily
stored in the MatLab

TM

workspace environment. The filter response is displayed graphically with-

in MatLab

TM

for verification of program convergence and acceptability. To prevent loss, the coeffi-

cients sets can be stored as files on the PC in a designated folder, before exiting MatLab

TM

.

Note: the FCG software is provided as a convenience to the user. It is a tool to

facilitate standard FIR filter design. Experienced MatLab

TM

users may design their own

custom FIR filters for the SPPDM-01 using the appropriate MatLab

TM

FIR design tools, as

long as SPPDF-01 design constraints are met.

Design constraints on the SPPDM-01 FIR Filter Platform are:

• Frequency Range: 100 Hz to 20 kHz

• Maximum Number of Taps: 300.
Note: Low-pass and high-pass filters are easily configured but some versions of band­pass and band-reject filters might not converge mathematically within some of the con­straints. User may be required to try other parameter combinations until a converging
implementation is found.

Chapter II of this document will be directed to MatLab

TM

users who wish to use Frequency

Devices’ FCG-GUI to design standard FIR filters for the SPPDM-01. The experienced MatLab

TM

filter designer may skip Chapter II and go right to Chapter III, the Filter Coefficient Loader (FCL)
section.

The FCG software is a design tool for FIR filters to be used within the MatLabTMenviron-

ment. The FCG software provides for the entry of specific filter parameters into the MatLab

TM

environment allowing the MatLabTMengine to calculate coefficients that approximate the given fil­ter descriptions.

User must first determine filter type, followed by selection of various specification parame-

ters. Based on the selected values, MatLab

TM

creates a best approximation set of coefficients.
This set of coefficients corresponds to a single or multiple number of filters and may be managed
in two modes: Immediate and Batch.

• Immediate Mode of operation relies on the MatLab

TM

workspace to present the set of

coefficients as an M x N matrix where M is the number of filters and N is the number
of coefficients for each filter. See Appendix A - Examples 2 and 3.

• Batch Mode of operation creates a text batch file where the system saves the set
of coefficients uniquely identified by the various filters. See Appendix A – Examples

4 and 5.

5

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Filter Coefficient Generator

Chapter II

2.1. FCG Installation and Startup:

Install the FCG software by inserting the CDDF-01 disk into the PC, CDRom drive.
Select the drive in Explorer or use the RUN menu.

CLICK on the Filter Coefficient Generator folder, then
CLICK on "SETUP" and follow the instructions on the installation window.

After installation of the software, two shortcuts will be inserted on the desktop, namely

FCG and FCGScript. Configure the software to run under the installed version of MatLab

TM

by
running the FCGConfig file located under the FCG directory, Program Files in the Windows direc­tory. The FCGConfig program will ask and set the location of your MatLab

TM

engine file:

matlab.exe.

After configuring the environment, DOUBLE CLICK on the new short cut called FCG on

the PC desktop to start the program.

The experienced user may skip the above steps by loading the MatLab

TM

environment,
going to the specific directories, and making the necessary initializations and M-file calls from
within MatLab

TM

. This will automatically invoke the FCG main panel GUI.

2.2 FCG GUI Control Group Descriptions

The components of the main panel are shown in the Figure 2 below:

Figure 2 – Filter Coefficient Generator Main Panel

6

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Chapter II

The main panel GUI is divided into five functional groups. Note: All entries or selections must

be completed in all groups before the "Apply" command (which initiates the filter coeffi­cient generation) is executed.

2.2.1 Group A, Filter (Items 1 - 5) - contain the controls necessary to specify the parameters

used in the generation of sets of coefficients for single or multiple filters over a predefined
bandwidth.

1. Filter Type List Control: Is used to select filter type. Select Low-Pass, High-Pass,

Band-Pass or Band-Stop. The default value shown at startup is Low-Pass. When

selecting Low-Pass or High-Pass Filter Type, the Second Pass-band Cutoff Input
Control (Fp2) and the Second Stop-band Cutoff Input Control (Fs2) will be disabled.

2. Sampling Frequency Input Control: Specifies the sampling frequency. Sampling fre­quency must be entered. Required sampling rate for the SPPDM-01 family of prod-

ucts is always 48000Hz.

3. Frequency Step Input Control: Enters a constant that represents the frequency steps

for the generation of the sets of filter coefficients over the bandwidth for a particular fil­ter. Since there is a limit to the maximum number of steps, small step sizes may limit
bandwidth. The Frequency Step (Fstep) represents a positive number limited by
SPPDM-01 family parameters such as the Maximum Bandwidth (MB) (100 to 20,000
Hz) and the Maximum Number of Filters (MNF = 512). For a specific filter, the Per Step
Maximum Number of Filters (PSMNF) is calculated to be PSMNF = MB / Fstep. This
value must be greater than one and less than MNF. The frequency step value is mean­ingless when only one set of filter coefficients is generated. A valid Fstep must be

entered.

4. From: Range Input Control is used to enter a numeric value for the lowest bandwidth

limit. It represents the starting point in the generation of the sets of filter coefficients.
The “To” (Item 5) is enabled when a valid number is entered into From. The number
must be between 1 and the MNF of 512.

5. To: Range Input Control enters a numeric value for the highest bandwidth limit. It rep­resents the end point used in the generation of the sets of filter coefficients. The num­ber must be between 1 and 512 for the frequency step. The number must be equal or
greater than the “From” number (Item 4). This control remains disabled until a valid

From value is entered. Then a valid To value can be entered.

2.2.2 Group B, Signal (Items 6 - 11) - are the controls used to input the relative specifications

for the filter(s) described in Group A.

6. Fp/Fp1: First Pass-band Cutoff Input Control enters a numeric value interpreted as

Pass-band Cutoff Frequency (Fp in Hz) for low-pass and high-pass type filters and as
First Pass-band Cutoff (Fp1) frequency for band-pass and band-stop type filters.

7. Fp2: Second Pass-band Cutoff Input Control enters a numeric value interpreted as

Second Pass-band Cutoff Frequency (Fp2 in Hz) for band-pass and band-stop type fil­ters. This control is enabled only when the Filter Type (Item 1, Figure 1) selected is
either Band-Pass or Band-Stop.

7

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Chapter II

8. Rp: Pass-band Ripple Input Control enters a numeric value interpreted as the Pass-

band Ripple (Rp in dB) for every type of filter selected. When entering values, a good
ripple value is one that produces convergence in the FIR coefficient generation algo­rithms when combined with the other relative specifications. Common values of ripple
for convergence are from 0.01 to 0.1 dB.

9. Fs/Fs1: First Stop-band Cutoff Input Control enters a numeric value interpreted as

Stop-band Cutoff Frequency (Fs in Hz) for low-pass and high-pass type filters and as
First Stop-band Cutoff Frequency (Fs1) for band-pass and band-stop type of filters.

10. Fs2: Second Stop-band Cutoff Input Control enters a numeric value interpreted as

Second Stop-band Cutoff Frequency (Fs2 in Hz) for band-pass and band-stop type of
filters. This control is enabled only when the Filter Type (Item 1, Figure 1) selected is
either Band Pass or Band Stop.

11. Rs: Stop-band Attenuation Input Control enters a numeric value interpreted as the

Stop-band Attenuation (Rs in dB) for every type of filter selected. The stop-band atten­uation must be less than or equal to the maximum bandwidth. Valid stop-band atten-

uation must be entered.

2.2.3 Group C, Coefficient Location (Items 12 - 14) - manages the two available modes of

operation: Immediate mode and Batch mode.

12. Workspace: CLICK this button whenever the set/sets of filter coefficients are to be

dumped into the MatLab

TM

Workspace. This provides immediate access of the coeffi-

cients through a matrix data structure in the workspace. User may want to initialize an
Mx Nmatrix variable that will contain the coefficient data where M is the number of fil­ters and N is the number of coefficients per filter. Note: data will be lost if the work-

space is cleared, or in quitting the MatLab

TM

environment without saving the vari-

able contents.

13. Other Location: CLICK this button whenever the set/sets of filter coefficients are to be

down loaded to a specific text file. This provides access to the coefficients at a later
time. For example, the file may be accessed and its contents read into a matrix struc­ture in the workspace. The inexperienced user should use this mode of operation
when attempting to use the FCG - FGL setup. The experienced user may accomplish
every task from within MatLab

TM

, allowing the use of the systems in immediate mode.

Selecting this control enables the Batch Mode Input Control Window next to the

Other Location button.

14. Batch Mode Input Control Window: This window is enabled whenever the Other
Location button is selected. This window allows entry of files from any other location

different from the MatLab

TM

workspace. Complete pathname must be entered for the

file destination. The name of the file must have the ".coe" suffix, otherwise it will
not be validated. The file created will identify each set of coefficients using the follow­ing format: filt1 tab-character coefficient1 tab-character coefficient2 tab-character …
coefficientN newline filt2 …

8

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Chapter II

2.2.4 Group D, Message (Items 15 - 16) - contains an indicator that shows system status, and

generation process information at specific instances. This group also presents controls’
(tooltips) about functional characteristics.

15.Message Text Box Window: This window continuously shows messages and process

status conditions. It provides next step usage indications to help user/system interaction.
It serves as a tool to obtain information about the system status and the coefficients gen­eration process.

16.Tooltip Indicator: Placing the cursor over any message or status line in the window, will

produce a drop down text with an explanation. To obtain next step; process instructions,
controls, indicator purpose, functions, or descriptions, place cursor over any control or
indicator in the FCG panel. This tool is used to learn about a control or indicator function
before its use.

2.2.5 Group E, Command (Items 17 - 20) - allows the user to initiate certain process/system

commands.

17. Apply: Using this command button starts the filter generation process using the entered

group of parameters. It also initiates plots of filter amplitude and phase for each set of
coefficients generated. The command enables execution only after appropriate parame­ters have been entered and validated. After completion, it sends the coefficients to the
location specified in the Coefficients’ Location Group (Group C, Items 12, 13 and 14).

18. "Undo" & 19. "Clear" Command Buttons: These command buttons are "dummy" but-

tons. They are for features yet to be implemented. They are provided as tools for an
experienced programmer who wishes to add commands to start a specific sequence of
instructions. Their default function is to present a message to the user.

20. Exit: Use this command button to exit the software. It closes any open windows and

quits the FCG system. The MatLab

TM

environment may continue to be used after exiting

the FCG software.

9

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SPPDF-01 Development Suite

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Filter Coefficient Loader

Chapter III

The Filter Coefficients Loader (FCL) Software is a tool that performs the interface, com-

munication, translation, and formatting functions for single or multiple sets of coefficients and dif­ferent filter types for loading into an SPPDM-01 platform using the SPPDB-01 development
board. The FCL also reformats and initiates the translation of FIR filter coefficient data into a for­mat that is recognized by the SPPDM-01 hardware as coefficients that influence the imbedded
FIR filter algorithm.

FCL allows the user to issue a single command to select and load mode of operation, seri­al communication parameters, and filter addresses in memory space. The user starts the
process that implements the SPPDB-01, RS232 serial communication port, using a translation­formatter to transform the "raw" coefficient data into FIR specifications recognized by the
SPPDM-01 FIR filter algorithm. For this to occur, the FCL uses a "software plug" (see Appendix
B) that groups a set of dynamically linked subroutines for translation formatting of coefficient data
into a recognizable pattern of information. It also uses a graphical user interface that implements
a serial communication protocol for the loading of coefficients into the SPPDM-01.

The FCL’s role in FIR design and application is to provide the means for the filter coeffi­cients generated, from relative specifications, to be interpreted as valid frequency-magnitude/fre­quency-phase characteristics by the SPPDM-01. This allows performance of real time analysis,
experiments, decision-making, etc. in an easy, fast, reliable and repeatable way.

3.1 Equipment Required:
Provided by Frequency Devices

3.1.1 SPPDF-01 FIR Filter Development Suite

• SPPDM-01 FIR filter platform

• SPPDB-01 Design/Development Board

3.1.2 Filter Coefficients Generator and Loader Software Installation Disk, CDDF-01

3.1.3 RS232 cable and connectors, provided with SPPDF-01
Provided by Customer

3.1.4 PC Test Station (Windows 9x or more) MatLabTMV5.3 or higher

3.1.5 ±15Vdc, +5Vdc Power Supply

3.2 Installation and Startup:

To install the FCL software, insert the CDDF-01 disk provided with the Development Suite
in the appropriate CDRom drive.

• Select the Filter Coefficient Loader folder

• RUN setup and follow instructions on the installation window.

10