Altera FIR Compiler II MegaCore Function User Manual
Page 50
Figure 4-20: Correct Input Format (15 valid cycles, 17 invalid cycles)
areset
clk
xin_v[0]
xin_c[7:0]
xin_0[7:0]
xout_v[0]
xout_c[7:0]
xout_0[17:0]
xout_1[17:0]
xout_2[17:0]
xout_3[17:0]
xout_4[17:0]
1
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
8
1
2
3
4
5
1
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
8
16 24 6 12 18
0
3FFF93FFF23FFEB
32 40 48 24 30 36
0
3FFE43FFDD3FFD6
56 64 72 42 48 54
0
3FFCF3FFC83FFC1
80 88 96 60 66 72
0
3FFBA3FFB33FFAC
104 112 120 78 84 90
0
3FFA53FF9E3FF97
Figure 4-21: Incorrect Input Format (15 valid cycles, 0 invalid cycles)If the number of invalid cycles is
less than 17, the output format is incorrect,
areset
clk
xin_v[0]
xin_c[7:0]
xin_0[7:0]
xout_v[0]
xout_c[7:0]
xout_0[17:0]
xout_1[17:0]
xout_2[17:0]
xout_3[17:0]
xout_4[17:0]
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
1
0
1
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
8
16 24 6
12 18
0
32 40 48 24 30 36
0
56 64 72 42 48 54
0
80 88 96 60 66 72
0
104 112 120 78 84 90
0
Figure 4-22: Correct Input Format (15 valid cycles, 20 invalid cycles)
areset
clk
xin_v[0]
xin_c[7:0]
xin_0[7:0]
xout_v[0]
xout_c[7:0]
xout_0[17:0]
xout_1[17:0]
xout_2[17:0]
xout_3[17:0]
xout_4[17:0]
1
0
1
2
3
4
5
6
7
8
9
10 11
12 13 14
15
8
1
1
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
2
0
1
8
16
24 6
12
18
0
3FFF9 3FFF2
32 40
48 24 30
36
0
3FFE4 3FFDD
56 64
72 42
48 54
0
3FFCF 3FFC8
80 88
96 60
66 72
0
3FFBA3FFB3
104 112 120 78
84 90
0
3FFA53FF9E
22 Channels with 11 Valid Cycles and 9 Invalid Cycles
An example where the clock rate = 200, sample rate = 10 yields a TDM factor of 20, inputChannelNum =
22 and interpolation factor is 10. In this case, the TDM factor is less than inputChannelNum. The
optimization produces a filter with PhysChanIn = 2, ChansPerPhyIn = 11, PhysChanOut = 11, and
ChansPerPhyOut = 2.
The input format in this case is 20 cycles long, which comes from the TDM factor. The number of
channels is 22, so the filter expects 11 (ChansPerPhyIn) valid cycles, followed by 9 invalid cycles (TDM
factor – ChansPerPhyIn = 20 – 11). Y
UG-01072
2014.12.15
22 Channels with 11 Valid Cycles and 9 Invalid Cycles
4-17
FIR II IP Core Functional Description
Altera Corporation