"TMS320C55x DSP Library DSPLIB Programmer's Reference"

subr[nx]nxscaleoflagPointer to output data vector of size nx containing (x–y) if scale =0 (x–y)/2 if scale =1Number of elements of input and output vectors.nx ≥ 4Scale selection If scale = 1, divide the result by 2 to prevent overflow. If scale = 0, do not divide by 2.Overflow flag. If oflag = 1, a 32-bit overflow has occurred. If oflag = 0, a 32-bit overflow has not occurred.DescriptionThis function subtracts two vectors, element by element.Algorithm 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 noneExampleBenchmarksSee examples/sub subdirectory(preliminary)Cycles † Core: 3 * nxOverhead: 23Code size(in bytes)60† Assumes all data is in on-chip dual-access RAM and that there is no bus conflict due to twiddletable reads and instruction fetches (provided linker command file reflects those conditions).Function Descriptions4-91