"TMS320C55x DSP Library DSPLIB Programmer's Reference"

convol1Figure 4–6. h Array in Memoryh(0)h(1)•h(nh–2)h(nh–1)lowest memory addresshighest memory addressExampleBenchmarksSee examples/convol subdirectory(preliminary)Cycles † Core: nr * (1 + nh)Overhead: 44Code size(in bytes)88† 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).convol1FunctionConvolution (fast)ushort oflag = convol1 (DATA *x, DATA *h, DATA *r, ushort nr, ushort nh)Argumentsx[nr+nh–1]h[nh]r[nr]nrPointer to input vector of nr+nh–1 real elements.Pointer to input vector of nh real elements.Pointer to output vector of nr real elements. In-placecomputation (r = x) is allowed (see Description section forcomment).Number of elements in vector r. Must be an even number.nh Number of elements in vector h.oflagOverflow error flag (returned value) If oflag = 1, a 32-bit data overflow occurred in an intermediateor final result.If oflag = 0, a 32-bit overflow has not occurred.Function Descriptions4-25