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SPPDF-01 Development Suite
User’s Manual
Filter Coefficient Generator
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 algo-
rithms 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 atten-
uation 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
M x N matrix variable that will contain the coefficient data where M is the number of fil-
ters 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 struc-
ture 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 follow-
ing format: filt1 tab-character coefficient1 tab-character coefficient2 tab-character …
coefficientN newline filt2 …
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