Texas Instruments C28 Series User Manual

Function Descriptions
3.16 Finite Impulse Response Filter
Description:
This routine implements the non-recursive difference equation of an all-zero filter (FIR), of
order N. All the coefficients of all-zero filter are assumed to be less than 1 in magnitude.
Header File:
FPU.h
Declaration:
void FIR_FP_calc(FIR_FP_handle)
Usage:
A pointer to the following structure is passed to the FIR_f32 function:
typedef struct {
float
*
coeff_ptr;
float
*
dbuffer_ptr;
int cbindex;
int order;
float input;
float output;
void (
*
init)(void
*
);
void (
*
calc)(void
*
);
}FIR_FP;
Table 3.21 describes each element
Item Description Format Comment
coeff_ptr Pointer to Filter coefficient Pointer to 32-bit float array Place the coefficients in a section (e.g.
“coeffilt”) aligned to 2x number of coef-
ficients
dbuffer_ptr Delay buffer ptr Pointer to 32-bit float array Place the Delay in a section (e.g.
“firldb”) aligned to an even number of
words
cbindex Circular Buffer Index Uint16 Index to the delay buffer
order Order of the Filter Uint16 Order is number of coefficients minus
one
input Latest Input sample 32-bit float can be assigned to an ADC input
output Filter Output 32-bit float
*init Pointer to Init funtion n/a Points to FIR_FP_init
*calc Pointer to calc funtion n/a Points to FIR_FP_calc
Table 3.21: Elements of the Data Structure
Sep 10, 2012 46

Texas Instruments C28 Series Specifications

General

Architecture	32-bit
Core	TMS320C28x
Operating Voltage	3.3 V
Operating Temperature	-40°C to 125°C
ADC	12-bit
Communication Interfaces	CAN, SPI, I2C, SCI
Peripherals	Timers
Package	Various (e.g., LQFP, BGA)

Summary

Introduction to C28x FPU Library

C28x FPU Library Structure

Library Build Options

Details the compiler options used to build the FPU library.

FPU Library Header Files

Explains the purpose and content of the library's header files.

C Functions and IQMath Integration

Discusses the use of C functions and IQMath in the FPU library.

C28x FPU Library Function Descriptions

DSP Routines Overview

Covers Fast Fourier Transforms (FFT) and related functions for signal processing.

Vector and Matrix Operations

Provides functions for element-wise operations on complex and real vectors.

Core Math Functions

Includes fundamental math operations like square root.

Optimized Utility Functions

Offers optimized memory copy and set operations.

FPU Library Revision History

Important Notice and Disclaimers