Altera FIR Compiler User Manual

Page 47

Chapter 4: Functional Description

4–5

FIR Compiler

Altera Corporation

FIR Compiler User Guide

where:

■

<FIR structure> is:

■

MCV—multicycle variable

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SER—fully serial

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MBS—multibit serial

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PAR—fully parallel

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<coefficient store> is:

■

LC—logic cells

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M512—M512 and MLAB blocks

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M4K—M4K and M9K blocks

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AUTO—Automatic memory block selection

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<allow or disallow symmetry> is:

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MSYM—Take advantage of symmetric coefficients

■

NOSYM—Use nonsymmetric coefficients

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<number of calculations for MCV|coefficient bit width for others> is:

■

for multicycle variable filters, the number of clock cycles to calculate the result

■

for all other filters, use the coefficient bit width

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<number of coefficient sets> is the user-specified number of coefficient sets

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<filter rate> is be specified as one of the following (SGL, INT, DEC)

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SGL—Single Rate FIR Filter

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INT—Interpolating FIR Filter

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DEC—Decimating FIR Filter

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<filter factor> is an integer value representing the rate-changing factor.

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For single-rate filters, this argument should be set to 1

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For multirate FIR filters, this argument should be an integer between 1 and 16

■

<coefficient bit width> is the integer value representing the user-specified coefficient
bit width, which ranges from 2-32

For example:

coef_seq.exe D:/FIR/coef_log.txt D:/FIR/coef_in.txt MCV M4K MSYM 4 1 SGL 1 8

The program checks for symmetry automatically, but you can force it to disallow
symmetry. Your specification should be consistent with the setting in the FIR
Compiler wizard.

The reloading capability allows you to change coefficient values. These filters may
contain optimizations for symmetrical filters. If you want a filter that may need both
symmetrical and non-symmetrical filters, turn on Force Non-Symmetrical Structures
in the Architecture Specification section of the Parameterize FIR Compiler page.