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tap

One of the weights a FIR filter multiplies its recent inputs by.

A tap is a coefficient h_i of a FIR filter, the weight applied to the input i samples ago; on a microcontroller taps are often stored in Q15.

Examples

  • The 5-tap low-pass's taps 1/8, 1/4, 1/4, 1/4, 1/8 add up to 1, which is why its 32-bit accumulator can't overflow.

  • Stored in Q15, a tap of 1/4 is the integer 8192 and a tap of 1/8 is 4096.

See also

FIR filter Q format fixed-point number
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