FIR filter with counting function

Abstract

The invention discloses an FIR (Finite Impulse Response) filter with an automatic counting function. The FIR filter comprises a read-write control module, a filtering calculation module, a data cache space and a filter coefficient memory, the read-write control module is used for sequentially reading the to-be-filtered data from the data cache space by using read addresses generated by counting according to the size relationship between the number of the to-be-filtered data written into the data cache space and a transposition enabling counting threshold value of the FIR filter, and sending the to-be-filtered data to the FIR filter; the read data to be filtered is transmitted to the filtering calculation module; the filtering calculation module is used for controlling the to-be-filtered data output by the data cache space and the filter coefficient output by the filter coefficient memory to perform filtering calculation; wherein the filtering calculation mode is matched with the size relation between the number of the data to be filtered written into the data cache space and the transposition enabling counting threshold value of the FIR filter.

Description

technical field [0001] The invention relates to the technical field of finite impulse response filters, in particular to an FIR filter with a counting function. Background technique [0002] Among the digital filters, the FIR (Finite Impulse Response) filter is a finite-length unit impulse response digital filter, which is the most basic component in a digital signal processing system. It can guarantee arbitrary amplitude-frequency characteristics while having strict Linear phase-frequency characteristics, and its unit sampling response is finite. Therefore, FIR filters are widely used in communication, image processing, pattern recognition and other fields. [0003] The order of the FIR filter refers to the number of filtered harmonics; the length of the FIR filter reflects the frequency band range of the filter; the sum of the order of the FIR filter and the value 1 is equal to the number of coefficients of the FIR filter, which is also equal to the filter The number of t...

AI Technical Summary

Problems solved by technology

[0005] Filter the noise and extract the sampled signal to filter the signal to obtain a signal with a low sampling rate or a high sampling rate and a high-quality signal for audio decoding, adaptive processing, etc. to achieve down-conversion or up-conversion Purpose, in the above process, the FIR filter transmits data serially. For an N-order FIR filter, each data read from its internal buffer is the same as the previous N-1 needs from the same buffer. The data sequence for filtering calculation is related. In the FIR filter existing in the prior art, the capacity of the storage space is often ignored, and in order to overcome the problem of inserting noise signals in the prior art, the data involved in the calculation between different clock cycles will be controlled. The sequence periodically suspends transmission, but it will affect the continuity or correlation between new data and old data, and it is difficult to filter and process effective results from valid data

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