| # |
setup |
A/D rms |
Relative
noise power vs fftlen |
8192 1fff |
4096 fff |
2048 7ff |
1024 3ff |
512 1ff |
256 ff |
||||
| 8k |
4k |
2k |
1k |
.5k |
|||||||||
| 1 |
jun08 standard 9 shifts then 0,1... |
30 |
1/2 |
1 |
1/2 |
1 |
1/2 |
0x1ff5 1 1111 1111 0101 shifts=11 |
0xffa 1111 1111 1010 shifts=10 |
0x7fd 111 1111 1101 shifts=10 |
0x3fe 11 1111 1110 shifts=9 |
0x1ff shifts=9 |
0xff shifts=8 |
| 2 |
9 shifts then 0,1 |
15 |
1/8 |
1/4 |
1/8 |
1/4 |
1/8 |
.. |
.. |
.. |
.. |
.. |
.. |
| 3 |
10 shifts then 0,1,0,1 |
30 |
1/2 |
1/4 |
1/2 |
1/4 |
1/2 |
0x1ffa 1 1111 1111 1010 shifts=11 |
0xffd 1111 1111 1101 shifts=11 |
0x7fe 111 1111 1110 shifts=10 |
0x3ff 11 1111 1111 shifts=10 |
0x1ff shifts=9 |
0xff shifts=8 |
| 4 |
butterfly 1,
no shift then 9 shifts, then 0,1 |
15 |
1/2 |
1 |
1/2 |
1/4 |
2 |
0x0ffa 0 1111 1111 1010 shifts=10 |
0x7fd 0111 1111 1101 shifts=9 |
0x3fe 011 1111 1110 shifts=9 |
0x1ff 01 1111 1111 shifts=9 |
0x0ff 0 1111 1111 shifts=8 |
0x7f 0111 1111 shifts=7 |
| 5 |
butterfly 1, no shift then 10 shifts then 0,1 |
15 |
1/8 |
1/4 |
1/8 |
1/4 |
1/2 |
0x0ffd 0 1111 1111 1101 shifts=11 |
0x7fe 0111 1111 1110 shifts=10 |
0x3ff 011 1111 1111 shifts=10 |
0x1ff 01 1111 1111 shifts=9 |
0xff 0 1111 1111 shifts=8 |
0x7f 0111 1111 shifts=7 |
| date |
mode |
8k |
4k |
2k |
1k |
.5k |
| 02jul08(285,10) |
1 rms=30 |
no pfb ovdrflows, 0x1ff5 |
pfb overflow, 0xffa |
|||
| 02jul08 |
2 rms=15 |
no pfb overflows, 0x1ff5 |
pfb overflow, 0xffa |
|||
| 02jul08 |
4 rms=15 |
pfb overflow, 0x7fd |
||||
| 02jul08 |
rms=30 |
|||||
| 03jul08(285,10) |
1 rms=30 |
no pfb overflow, 0x1ff5 |
no pfb overflow, 0xffa |
pfb&adc overflows,0x3fe |
||
| 03jul08 |
2 rms=15 |
no pfb,noadc overflows,0x3fe |
||||
| 03jul08 |
3 rms=30 |
no pfb overflows,0x1ffa |
no pfb overflows,0xffd |
no pfb overflows, yes
adcOver.0x3ff |
||
| 03jul08 |
4 |