MikroElektronika
At the beginning of this chapter the functions used in this chapter will be described together with some other useful functions. Table 141 presents a list of the functions including a description of their parameters, results (functions only), and eventual restrictions on the parameter values
FIR_Radix
IIR_Radix
FFT
IFFT
BitReverseComplex
Vector_Set
VectorPower
Vector_Subtract
VectorScale
Vector_Negate
Vector_Multiply
Vector_Min
Vector_Max
Vector_Dot
Vector_Correlate
Vector_Convolve
Vector_Add
Matrix_Transponse
Matrix_Subtract
Matrix_Scale
Matrix_Multiply
Matrix_Add
FIR_Radix
Prototype 

Description  This function applies FIR filter to ptrInput. Input samples must be in Y data space.FilterOrder is order of the filter + 1.ptrCoeffs is address of filter coeffitients in program memory.BuffLength represents number of samples ptrInput points to.ptrInput is address of input samples.Index index of current sample. 
Returns  sum(k=0..N1)(coef[k]*input[Nk]) – Current sample of processed signal(B[n]) N – buffer length k – Current index 
IIR_Radix
Prototype  unsigned IIR_Radix (const int BScale, const int AScale, const signed *ptrB, const signed*ptrA, unsigned FilterOrder, unsigned *ptrInput, unsigned Input_Len, unsigned *ptrOutput,unsigned Index) 
Description  This function applies IIR filter to ptrInput. Input and output samples must be in Y data space.AScale A Scale factorBScale B Scale factorptrB Address of B coefficients (In program memory)ptrA Address of A coefficients (In program memory)FilterOrder is order of the filter + 1.ptrInput is address of input samples. Input_Len represents number of samples ptrInput points to.ptrOutput is address of output samples. Output length is equal to Input length.Index index of current sample. 
Returns  y[n]=sum(k=0..N)(Acoef[k]*x[nk]) – sum(k=1..M)(Bcoef[k]*y[nk]) 
FFT
Prototype  void Fft(unsigned log2N, const unsigned *TwiddleFactorsAddress, unsigned *Samples); 
Description  Function applies FFT transformation to input samples, input samples must be in Y data space.N – buffer length (must be the power of 2).TwiddleFactorsAddress is address of costant array which contains complex twiddle factors.The array is expected to be in program memory.Samples array of input samples.Upon completion complex array of FFT samples is placed in the Samples parameter. 
Returns  F(k) = 1/N*sum_n (f(n)*WN(kn)), WN(kn) = exp[(j*2*pi*k*n)/N] Fn – array of complex input samples n in {0, 1,… , N1}, and k in {0, 1,… , N1}, with N = 2^m, m element of Z. WN – TwiddleFactorsThe amplitude of current FFT sample is calculated as: F[k]=sqrt(Re[k]^2+ Im[k]^2) 
Note 
Complex array of FFT samples is placed in Samples parameter. Input Samples are arranged in manner Re,Im,Re,Im… (where Im is always zero). Output samples are arranged in the same manner but Im parts are different from zero. Output samples are symmetrical (First half of output samples (index from 0 to N/2) is identical to the second half of output samples(index from N/2 to N). Input data is a complex vector such that the magnitude of the real and imaginary parts of each of its elements is less than 0.5. If greater or equal to this value the results could produce saturation. Note that the output values are scaled by a factor of 1/N, with N the length of the FFT. input is expected in natural ordering, while output is produced in bit reverse ordering. 
BitReverseComplex
Prototype  void BitReverseComplex(unsigned log2N, unsigned *ReIm) 
Description  This function does Complex (inplace) Bit Reverse reorganization.N – buffer length (must be the power of 2).ReIm – Output Sample(from FFT). 
Note  Input samples must be in Y data space. 
Vector_Set
Prototype  void Vector_Set(unsigned *input, unsigned size, unsigned value); 
Description  Sets size elements of input to value , starting from the first element.Size must be > 0. Length of input is limited by available ram 
VectorPower
Prototype  unsigned VectorPower(unsigned N, unsigned *Vector); 
Description  Function returns result of power value (powVal) in radix point 1.15 
Operation  powVal = sum (srcV[n] * srcV[n]) with n in {0, 1,… , numElems1} 
Input  N = number of the elements in vector(s) (numElems)Vector = ptr to source vector (srcV) 
Note  AccuA used, not restored CORCON saved, used, restored 
Vector_Subtract
Prototype  void Vector_Subtract(unsigned *dest, unsigned *v1, unsigned *v2, unsigned numElems); 
Description  This procedure does substraction of two vectors. numElems must be less or equal to minimum size of two vectors.v1 – First Vectorv2 – Second Vectordest – Result Vector 
Operation  dstV[n] = srcV1[n] – srcV2[n] with n in {0, 1,… , numElems1} 
Note  AccuA used, not restored. CORCON saved, used, restored. 
VectorScale
Prototype  void VectorScale(unsigned N, int ScaleValue, unsigned *SrcVector, unsigned *DestVector); 
Description  This procedure does vector scaling with scale value.N – Buffer lengthSrcVector – original vectorDestVector – scaled vectorScaleValue – Scale Value 
Operation  dstV[n] = sclVal * srcV[n], with n in {0, 1,… , numElems1} 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Vector_Negate
Prototype  void Vector_Negate(unsigned *srcVector, unsigned *DestVector, unsigned numElems); 
Description  This procedure does negation of vector.srcVector – Original vectordestVector – Result vectornumElems – Number of Elements 
Operation  dstV[n] = (1)*srcV1[n] + 0, 0 <= n < numElems 
Note  Negate of 0x8000 is 0x7FFF. AccuA used, not restored. CORCON saved, used, restored. 
Vector_Multiply
Prototype  void Vector_Multiply(unsigned *v1, unsigned *v2, unsigned *dest, unsigned numElems); 
Description  This procedure does multiplication of two vectors.numElems must be less or equal to minimum size of two vectors.v1 – First Vectorv2 – Second Vectordest – Result Vector 
Operation  dstV[n] = srcV1[n] * srcV2[n] with n in {0, 1,… , numElems1} 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Vector_Min
Prototype  unsigned Vector_Min(unsigned *Vector, unsigned numElems, unsigned *MinIndex); 
Description  This function find min. value in vector.Vector – Original vector.numElems – Number of elementsMinIndex – Index of minimum value 
Operation  minVal = min {srcV[n], n in {0, 1,…numElems1} if srcV[i] = srcV[j] = minVal, and i < j, then minIndex = j 
Returns  minimum value (minVal) 
Vector_Max
Prototype  unsigned Vector_Max(unsigned *Vector, unsigned numElems, unsigned *MaxIndex); 
Description  This function find max. value in vector.Vector – Original vector.numElems – Number of elementsMaxIndex – Index of maximum value 
Operation  maxVal = max {srcV[n], n in {0, 1,…numElems1} } if srcV[i] = srcV[j] = maxVal, and i < j, then maxIndex = j 
Returns  maximum value (maxVal) 
Vector_Dot
Prototype  unsigned Vector_Dot(unsigned *v1, unsigned *v2, unsigned numElems); 
Description  Procedure calculates vector dot product.v1 – First vector.v2 – Second vectornumElems – Number of elements 
Operation  dotVal = sum (srcV1[n] * srcV2[n]), with n in {0, 1,… , numElems1} 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Vector_Correlate
Prototype  void Vector_Correlate(unsigned *v1, unsigned *v2, unsigned *dest, unsigned numElemsV1,unsigned numElemsV2); 
Description  Procedure calculates Vector correlation (using convolution).v1 – First vector.v2 – Second vectornumElemsV1 – Number of first vector elementsnumElemsV2 – Number of second vector elementsdest – Result vector 
Operation  r[n] = sum_(k=0:N1){x[k]*y[k+n]}, where: x[n] defined for 0 <= n < N, y[n] defined for 0 <= n < M, (M <= N), r[n] defined for 0 <= n < N+M1. 
Vector_Convolve
Prototype  void Vector_Convolve(unsigned *v1, unsigned *v2, unsigned *dest, unsigned numElemsV1, unsignednumElemsV2); 
Description  Procedure calculates Vector using convolution.v1 – First vector.v2 – Second vectornumElemsV1 – Number of first vector elementsnumElemsV2 – Number of second vector elementsdest – Result vector 
Operation  y[n] = sum_(k=0:n){x[k]*h[nk]}, 0 <= n < M y[n] = sum_(k=nM+1:n){x[k]*h[nk]}, M <= n < N y[n] = sum_(k=nM+1:N1){x[k]*h[nk]}, N <= n < N+M1 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Vector_Add
Prototype  void Vector_Add(unsigned *dest, unsigned *v1, unsigned *v2, unsigned numElems); 
Description  Procedure calculates vector addition.v1 – First vector.v2 – Second vectornumElems – Number of vector elementsdest – Result vector 
Operation  dstV[n] = srcV1[n] + srcV2[n], with n in {0, 1,… , numElems1} 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Matrix_Transponse
Prototype  void Matrix_Transpose(unsigned * src, unsigned * dest, unsigned num_rows, unsigned num_cols); 
Description  Procedure does matrix transposition.src – Original matrix.dest – Result matrixnumRows – Number of matrix rowsnumCols – Number of matrix columns 
Operation  dstM[i][j] = srcM[j][i] 
Matrix_Subtract
Prototype  void Matrix_Subtract(unsigned * src1, unsigned * src2, unsigned * dest, unsigned num_rows,unsigned num_cols); 
Description  Procedure does matrix substraction.src1 – First matrix.src2 – Second matrixdest – Result matrixnum_rows – Number of matrix rowsnum_cols – Number of matrix columns 
Operation  dstM[i][j] = srcM1[i][j] – srcM2[i][j] 
Note  AccuA used, not restored. AccuB used, not restored. CORCON saved, used, restored. 
Matrix_Scale
Prototype  void Matrix_Scale(unsigned scale_value, unsigned *src1, unsigned *dest, unsigned num_rows,unsigned num_cols); 
Description  Procedure does matrix scale.ScaleValue – Scale Valuesrc1 – Original matrixdest – Result matrixnum_rows – Number of matrix rowsnum_cols – Number of matrix columns 
Operation  dstM[i][j] = sclVal * srcM[i][j] 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Matrix_Multiply
Prototype  void Matrix_Multiply(unsigned * src1, unsigned * src2, unsigned * dest, unsigned numRows1,unsigned numCols2, unsigned numCols1Rows2); 
Description  Procedure does matrix multiply.src1 – First Matrixsrc2 – Second Matrixdest – Result MatrixnumRows1 – Number of first matrix rowsnumCols2 – Number of second matrix columnsnumCols1Rows2 – Number of first matrix columns and second matrix rows 
Operation  dstM[i][j] = sum_k(srcM1[i][k]*srcM2[k][j]), with i in {0, 1, …, numRows11} j in {0, 1, …, numCols21} k in {0, 1, …, numCols1Rows21} 
Note  AccuA used, not restored. CORCON saved, used, restored. 
Matrix_Add
Prototype  void Matrix_Add(unsigned * src1, unsigned * src2, unsigned * dest, unsigned numRows, unsignednumCols); 
Description  Procedure does matrix addition.src1 – First Matrixsrc2 – Second Matrixdest – Result MatrixnumRows – Number of first matrix rowsnumCols – Number of second matrix columns 
Operation  dstM[i][j] = srcM1[i][j] + srcM2[i][j] 
Note  AccuA used, not restored. CORCON saved, used, restored. 