"TMS320C55x DSP Library DSPLIB Programmer's Reference"

firDescriptionComputes the exponent of elements of vector x using Taylor series.Algorithm for (i 0; i nx; i ) y(i) e x(i) where –1 x(i) 1Overflow Handling MethodologyNot applicableSpecial Requirements Linker command file: you must allocate .data section (for polynomial coefficients)Implementation Notes Computes the exponent of elements of vector x. It uses the following Taylorseries:exp(x) c0 (c1*x) (c2*x 2 ) (c3*x 3 ) (c4*x 4 ) (c5*x 5 )wherec0 = 1.0000c1 = 1.0001c2 = 0.4990c3 = 0.1705c4 = 0.0348c5 = 0.0139ExampleBenchmarksSee examples/expn subdirectory(preliminary)Cycles † Core: 11 * nxOverhead: 18Code size(in bytes)57† 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).firFunctionArgumentsFIR Filterushort oflag = fir (DATA *x, DATA *h, DATA *r, DATA *dbuffer, ushort nx,ushort nh)x[nx]Pointer to input vector of nx real elements.h[nh] Pointer to coefficient vector of size nh in normal order.For example, if nh=6, then h[nh] = {h0, h1, h2, h3, h4,h5} where h0 resides at the lowest memory addressin the array.This array must be located in internal memory sinceit is accessed by the C55x coefficient bus.4-34