"TMS320C55x DSP Library DSPLIB Programmer's Reference"

negr[nx]Pointer to output data vector of size nx containingnx Number of elements of input and output vectors. Nx 4oflagOverflow flagIf oflag = 1, a 32-bit overflow has occurredIf oflag = 0, a 32-bit overflow has not occurredDescriptionAlgorithmThis function multiplies two 32-bit Q31 vectors, element by element, andproduces a 32-bit Q31 vector.for (i=0; i < nx; i++)z (i) = x (i) * y (i)Overflow Handling MethodologyScaling implemented for overflow prevention (user selectable)Special Requirements noneImplementation Notes noneExampleSee examples/add subdirectoryBenchmarksCycles Core: 4*nx + 4Overhead 21Code size(in bytes)73negFunctionVector Negateushort oflag = neg (DATA *x, DATA *r, ushort nx)(defined in neg.asm)Argumentsx[nx]r[nx]Pointer to input data vector 1 of size nx. In-place processingallowed (r can be = x = y)Pointer to output data vector of size nx. In-place processingallowedSpecial cases: if x[I] = –1 = 32768 , then r = 1 = 321767 with oflag = 1 if x= 1 = 32767 , then r = –1 = 321768 with oflag = 1Function Descriptions4-77