Texas Instruments C28 Series User Manual

Function Descriptions
3.11 Real Fast Fourier Transform with ADC Input (Unaligned)
Description:
This module computes a 32-bit floating-point real FFT with 12-bit ADC input including input bit
reversing. This version of the function does not have any buffer alignment requirements. If you
can align the input buffer, then use the RFFT_adc_f32 function for improved performance.
Header File:
FPU.h
Declaration:
void RFFT_adc_f32u (RFFT_F32_STRUCT
*
)
Usage:
A pointer to the following structure is passed to the RFFT_adc_f32u function:
typedef struct {
Uint16
*
InBuf;
void
*
Tail;
} RFFT_ADC_F32_STRUCT;
typedef struct {
float32
*
InBuf;
float32
*
OutBuf;
float32
*
CosSinBuf;
float32
*
MagBuf;
float32
*
PhaseBuf;
Uint16 FFTSize;
Uint16 FFTStages;
} RFFT_F32_STRUCT;
Table 3.14 describes each element of the structure RFFT_ADC_F32_STRUCT and table
3.15 describes the elements of RFFT_F32_STRUCT, but note that its InBuf pointer is not used.
Alignment Requirements:
None
Notes:
1. If you can align the input buffer to a 2*FFTSize, then consider using the
RFFT_adc_f32 function. This version of the function has input buffer alignment
requirements, but it is more cycle efficient
2. All buffers and stack are placed in internal memory (zero-wait states in data space).
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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