"TMS320C55x DSP Library DSPLIB Programmer's Reference"

sqrt_16DescriptionComputes the sine of elements of vector x. It uses Taylor series to computethe sine of angle x.Algorithm for (i 0; i nx; i ) y(i) sin(x(i)) where x(i) xradpiOverflow Handling MethodologyNot applicableSpecial Requirements noneImplementation Notes Computes the sine of elements of vector x. It uses the following Taylor seriesto compute the angle x in quadrant 1 (0–pi/2).sin(x) = c1*x + c2*x^2 + c3*x^3 + c4*x^4 + c5*x^5c1 = 3.140625xc2 = 0.02026367c3 = – 5.3251c4 = 0.5446778c5 = 1.800293The angle x in other quadrant is calculated by using symmetries that map theangle x into quadrant 1.ExampleBenchmarksSee examples/sine subdirectory(preliminary)Cycles † Core: 19 * nxOverhead: 17Code size(in bytes)93 program; 3 data† 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).sqrt_16FunctionSquare Root of a 16-bit Numberushort oflag = sqrt_16 (DATA *x, DATA *r, short nx)(defined in sqrtv.asm)Argumentsx[nx]r[nx]Pointer to input vector of size nx.Pointer to output vector of size nx containing the sqrt(x).Function Descriptions4-89