用dsplib库中fir2函数分段滤波，对每一段待滤波数据的长度有什么要求？

还有，fir2函数中的delaybuffer的意义是什么？

请问用的是哪款器件？

delaybuffer的意义：

dbuffer[nh+2] Pointer to delay buffer of length nh = nh + 2

In the case of multiple-buffering schemes, this array should be initialized to 0 for the first filter block only. Between consecutive blocks, the delay buffer preserves the previous elements needed.