108 tiny-fir
108 : tiny-fir
- Author: Tom Schucker
- Description: 4bit 2-stage FIR filter
- GitHub repository
- Clock: 0 Hz
How it works
Multiplies the input by the tap coefficient for each stage and outputs the sum of all stages
How to test
Load tap coefficients by setting the value and pulsing 2 times, then repeat for second tap. Change input value each clock to run filter. Select signals change output to debug 00(normal) 01(output of mult 2) 10(tap values in mem) 11(output of mult 1). FIR output discards least significant bit due to output limitations
External hardware
Arduino or FPGA
IO
| # | Input | Output |
|---|---|---|
| 0 | clock | fir1/mult0/tap10 |
| 1 | data0/tap0 | fir2/mult1/tap11 |
| 2 | data1/tap1 | fir3/mult2/tap12 |
| 3 | data2/tap2 | fir4/mult3/tap13 |
| 4 | data3/tap3 | fir5/mult4/tap20 |
| 5 | select0 | fir6/mult5/tap21 |
| 6 | select1 | fir7/mult6/tap22 |
| 7 | loadpulse | fir8/mult7/tap23 |