Decimation Filter Details (Gen 1/Gen 2) - 2.6 English

Zynq UltraScale+ RFSoC RF Data Converter v2.6 Gen 1/2/3/DFE LogiCORE IP Product Guide (PG269)
Document ID
PG269
Release Date
2024-11-13
Version
2.6 English

The decimation filter chain consists of three FIR filters: FIR2, FIR1, and FIR0, which can be enabled to give successive decimation by a factor of two per stage. The filter transfer functions are as shown in the following figures.

Figure 1. FIR2 and FIR1 Frequency Response (Gen 1/Gen 2)
Figure 2. FIR0 and 2x Decimation Frequency Response (Gen 1/Gen 2)
Figure 3. 4x Decimation and 8x Decimation Frequency Response (Gen 1/Gen 2)

The filter coefficients for the decimation filters are shown in the following tables.

Table 1. FIR2—80% Pass-Band, 59-tap (Gen 1/Gen 2)
FIR2 1st Half 5 0 -17 0 44 0 -96 0 187 0 -335 0 565 0 -906
0 1401 0 -2112 0 3145 0 -4723 0 7415 0 -13331 0 41526  
Center Tap 65536  
2nd Half 5 0 -17 0 44 0 -96 0 187 0 -335 0 565 0 -906
0 1401 0 -2112 0 3145 0 -4723 0 7415 0 -13331 0 41526  
Table 2. FIR1—40% Pass-Band, 23-Tap (Gen 1/Gen 2)
FIR1 1st Half -12 0 84 0 -337 0 1008 0 -2693 0 10142
Center Tap 16384  
2nd Half -12 0 84 0 -337 0 1008 0 -2693 0 10142
Table 3. FIR0—20% Pass-Band, 15-Tap (Gen 1/Gen 2)
FIR0 1st Half -6 0 54 0 -254 0 1230
Center Tap 2048  
2nd Half -6 0 54 0 -254 0 1230