At the beginning of this chapter the functions and procedures used in this chapter will be described together with some other useful functions and procedures. Table 14-1 presents a list of the functions and procedures including a description of their parameters, results (functions only), and evenual restrictions on the paremeter 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	function FIR_Radix(FilterOrder: Word; ptrCoeffs: LongInt; BuffLength: Word; ptrInput: Word; Index: Word): Word;
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..N-1)(coef[k]*input[N-k]) - Current sample of processed signal(B[n]) N - buffer length k - Current index

IIR_Radix

Prototype	function IIR_Radix(BScale: Integer; AScale: Integer; ptrB: Word; ptrA: Word; FilterOrder: Word; ptrInput: Word; Input_Len: Word; ptrOutput: Word; Index: Word) : Word;
Description	This function applies IIR filter to ptrInput. Input and output samples must be in Y data space. AScale A Scale factor BScale B Scale factor ptrB 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[n-k]) - sum(k=1..M)(Bcoef[k]*y[n-k])

FFT

Prototype	procedure FFT(log2N: word; TwiddleFactorsAddress: LongInt; var Samples: array[1024] of word);
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,... , N-1}, and k in {0, 1,... , N-1}, 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.

IFFT

Prototype	procedure IFFT(log2N: word; TwiddleFactorsAddress: LongInt; var Samples: array[1024] of word);
Description	Function applies IFFT 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 IFFT samples is placed in the Samples parameter.
Operation	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,... , N-1}, and k in {0, 1,... , N-1}, with N = 2^m, m element of Z. WN - TwiddleFactors
Note	Complex array of IFFT samples is placed in Samples parameter. Input Samples are arranged in manner Re,Im,Re,Im... (where Im is always zero). 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 IFFT. Input is expected in bit reverse ordering, while output is produced in natural ordering.

BitReverseComplex

Prototype	procedure BitReverseComplex(log2N: word; var ReIm: array[1024] of word);
Description	This function does Complex (in-place) Bit Reverse re-organization. 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	procedure Vector_Set(var input: array[1024] of word; size, value: word);
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	function VectorPower(N: word; var Vector: array[1024] of word): word;
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,... , numElems-1}
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	procedure Vector_Subtract(var dest, v1, v2: array[1024] of word; numElems: word);
Description	This procedure does substraction of two vectors. numElems must be less or equal to minimum size of two vectors. v1 - First Vector v2 - Second Vector dest - Result Vector
Operation	dstV[n] = srcV1[n] - srcV2[n] with n in {0, 1,... , numElems-1}
Note	AccuA used, not restored. CORCON saved, used, restored.

VectorScale

Prototype	procedure VectorScale(N: word; ScaleValue: integer; var SrcVector, DestVector: array[1024] ofword);
Description	This procedure does vector scaling with scale value. N - Buffer length SrcVector - original vector DestVector - scaled vector ScaleValue - Scale Value
Operation	dstV[n] = sclVal * srcV[n], with n in {0, 1,... , numElems-1}
Note	AccuA used, not restored. CORCON saved, used, restored.

Vector_Negate

Prototype	procedure Vector_Negate(var srcVector, destVector: array[1024] of word; numElems: word);
Description	This procedure does negation of vector. srcVector - Original vector destVector - Result vector numElems - 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	procedure Vector_Multiply(var v1, v2, dest: array[1024] of word; numElems: word);
Description	This procedure does multiplication of two vectors. numElems must be less or equal to minimum size of two vectors. v1 - First Vector v2 - Second Vector dest - Result Vector
Operation	dstV[n] = srcV1[n] * srcV2[n] with n in {0, 1,... , numElems-1}
Note	AccuA used, not restored. CORCON saved, used, restored.

Vector_Min

Prototype	function Vector_Min(var Vector: array[1024] of word; numElems: word; var MinIndex: word): word;
Description	This function find min. value in vector. Vector - Original vector. numElems - Number of elements MinIndex - Index of minimum value
Operation	minVal = min {srcV[n], n in {0, 1,...numElems-1} if srcV[i] = srcV[j] = minVal, and i < j, then minIndex = j
Returns	minimum value (minVal)

Vector_Max

Prototype	function Vector_Max(var Vector: array[1024] of word; numElems: word; var MaxIndex: word): word;
Description	This function find max. value in vector. Vector - Original vector. numElems - Number of elements MaxIndex - Index of maximum value
Operation	maxVal = max {srcV[n], n in {0, 1,...numElems-1} } if srcV[i] = srcV[j] = maxVal, and i < j, then maxIndex = j
Returns	maximum value (maxVal)

Vector_Dot

Prototype	function Vector_Dot(var v1, v2: array[1024] of word; numElems: word): word;
Description	Procedure calculates vector dot product. v1 - First vector. v2 - Second vector numElems - Number of elements
Operation	dotVal = sum (srcV1[n] * srcV2[n]), with n in {0, 1,... , numElems-1}
Note	AccuA used, not restored. CORCON saved, used, restored.

Vector_Correlate

Prototype	procedure Vector_Correlate(var v1, v2, dest: array[1024] of word; numElemsV1, numElemsV2: word);
Description	Procedure calculates Vector correlation (using convolution). v1 - First vector. v2 - Second vector numElemsV1 - Number of first vector elements numElemsV2 - Number of second vector elements dest - Result vector
Operation	r[n] = sum_(k=0:N-1){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+M-1.

Vector_Convolve

Prototype	procedure Vector_Convolve(var v1, v2, dest: array[1024] of word; numElemsV1, numElemsV2: word);
Description	Procedure calculates Vector using convolution. v1 - First vector. v2 - Second vector numElemsV1 - Number of first vector elements numElemsV2 - Number of second vector elements dest - Result vector
Operation	y[n] = sum_(k=0:n){x[k]*h[n-k]}, 0 <= n < M y[n] = sum_(k=n-M+1:n){x[k]*h[n-k]}, M <= n < N y[n] = sum_(k=n-M+1:N-1){x[k]*h[n-k]}, N <= n < N+M-1
Note	AccuA used, not restored. CORCON saved, used, restored.

Vector_Add

Prototype	procedure Vector_Add(var dest, v1, v2: array[256] of word; numElems: word);
Description	Procedure calculates vector addition. v1 - First vector. v2 - Second vector numElems - Number of vector elements dest - Result vector
Operation	dstV[n] = srcV1[n] + srcV2[n], with n in {0, 1,... , numElems-1}
Note	AccuA used, not restored. CORCON saved, used, restored.

Matrix_Transponse

Prototype	procedure Matrix_Transponse(var src, dest: array[1024] of word; numRows, numCols: word);
Description	Procedure does matrix transposition. src - Original matrix. dest - Result matrix numRows - Number of matrix rows numCols - Number of matrix columns
Operation	dstM[i][j] = srcM[j][i]

Matrix_Subtract

Prototype	procedure Matrix_Subtract(var src1, src2, dest: array[1024] of word; numRows, numCols: word);
Description	Procedure does matrix substraction. src1 - First matrix. src2 - Second matrix dest - Result matrix numRows - Number of matrix rows numCols - 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	procedure Matrix_Scale(ScaleValue: word; var src1, dest: array[1024] of word; numRows, numCols: word);
Description	Procedure does matrix scale. ScaleValue - Scale Value src1 - Original matrix dest - Result matrix numRows - Number of matrix rows numCols - Number of matrix columns
Operation	dstM[i][j] = sclVal * srcM[i][j]
Note	AccuA used, not restored. CORCON saved, used, restored.

Matrix_Multiply

Prototype	procedure Matrix_Multiply(var src1, src2, dest: array[256] of word; numRows1, numCols2, numCols1Rows2: word);
Description	Procedure does matrix multiply. src1 - First Matrix src2 - Second Matrix dest - Result Matrix numRows1 - Number of first matrix rows numCols2 - Number of second matrix columns numCols1Rows2 - 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, ..., numRows1-1} j in {0, 1, ..., numCols2-1} k in {0, 1, ..., numCols1Rows2-1}
Note	AccuA used, not restored. CORCON saved, used, restored.

Matrix_Add

Prototype	procedure Matrix_Add(var src1, src2, dest: array[1024] of word; numRows, numCols: word);
Description	Procedure does matrix addition. src1 - First Matrix src2 - Second Matrix dest - Result Matrix numRows - Number of first matrix rows numCols - Number of second matrix columns
Operation	dstM[i][j] = srcM1[i][j] + srcM2[i][j]
Note	AccuA used, not restored. CORCON saved, used, restored.