"TMS320C55x DSP Library DSPLIB Programmer's Reference"

firinterpIoflagInterpolation factor. I is effectively the number ofoutput samples for every input sample. This routinecan be used with I=1.Overflow error flag If oflag = 1, a 32-bit data overflow occurred in anintermediate or final result.If oflag = 0, a 32-bit overflow has not occurred.DescriptionComputes an interpolating real FIR filter (direct-form) using coefficient storedin vector h. The real data input is stored in vector x. The filter output result isstored in vector r. This function retains the address of the delay filter memoryd containing the previous delayed values to allow consecutive processing ofblocks. This function can be used for both block-by-block and sample-bysamplefiltering (nx = 1).Algorithmr[t] nhk0h[k]x[tI k]0 j nrOverflow Handling MethodologyNo scaling implemented for overflow prevention.Special Requirements noneImplementation Notes noneExampleBenchmarksSee examples/decimate subdirectory(preliminary)CyclesCore:If I > 1nx*(2+I*(1+(nh/I)))If I=1 :nx*(2+nh)Overhead 72Code size(in bytes)164Function Descriptions4-43