DSP Functions in Shieldbuddy

The TriLib is a DSP Library for Aurix/TriCore and is C-callable.  It consists of hand-coded assembly, general purpose signal processing routines. These routines are extensively used in real-time applications where speed is critical.

The TriLib includes more than 60 commonly used DSP routines. The throughput of the system using the TriLib routines is considerably better than those achieved using the equivalent code written in ANSI C language. The TriLib significantly helps in understanding the general purpose signal processing routines, its implementation on TriCore. It also reduces the DSP application development time. The TriLib also provides the source code. Some example applications are also provided as part of TriLib to demonstrate the usage of functions.

The routines are broadly classified into the following functional categories:

• Complex Arithmetic
• Vector Arithmetic
• FIR Filters
• IIR Filters
• Adaptive Filters
• Fast Fourier Transforms
• Discrete Cosine Transform
• Mathematical functions
• Matrix operations
• Statistical functions

Specific Features
• Covers the common DSP algorithms with Source codes
• Hand-coded and optimized assembly modules
• Bit-exact reference C codes for easy understanding and verification of the algorithms
• Assembly implementation tested for bit exactness against model C codes
• Examples to demonstrate the usage of functions

The DSP functions are all accessible through the Arduino IDE:

void setup1() {
// put your setup code for core 1 here, to run once:


}


void loop1() {
// put your main code for core 1 here, to run repeatedly:

short NF;

// Generate the Twiddle factors
FFT_TF_32( TF1,nX1 );

// Real Fast Fourier Transform Forward with two real sequences
// Xa and Xb in real and imaginary parts of X1 respectively.
// Output will have first block FFT of Xa results of length N
// followed by second block FFT of Xb complex results of length N
digitalWrite(1,HIGH);
NF = FFTReal_2_32(R1, X1, TF1, nX1); // 4.6us on core0, 3.8us on core1
digitalWrite(1,LOW);

// Generate the Twiddle factors
FFT_TF_32( TF2, nX2 );


// The input is is arranged in Xa[0],Xa[1]....Xa[n-1],Xb[0],
// Xb[1]...Xbn-1] in a 2N length complex array and o/p is alternated
// by Xa[0], Xb[0]..Xa[N-1], Xa[N-1] in a N length complex input array.

digitalWrite(2,HIGH);
NF = IFFTReal_2_32(R2, X2, TF2, nX2, 0); // 5.5us on core0, 4.2us on core1
digitalWrite(2,LOW);

StopPoint = 1; //Only to set breakpoint


}