Sundance FC108 v.1.1 - Manual (Page 5)

FC108 - Polyphase filterbank v1.1
Fast
Polyphase filterbank product manual
December 2005 www.sundance.com - 5 -
I_in 16 Input Input data bus: In Phase component
Q_in 16 Input Input data bus: Quadrature Phase component
I_out 16 Output Output data bus: In Phase component
Q_out 16 Output Output data bus: Quadrature component
data_valid 1 Output Data valid signal: data on the I_out and Q_out bus are valid
overflow 1 Output Overflow: indicates if the FFT calculation has overflowed
during processing. If an overflow is detected the results
should be discarded and it is recommended to increase the
FFT scaling factor (FFT_scaling) for further processing.
Table 1 : Ports definition
Number of channels
The Number of channels is a parameter fed to the core. This parameter can be either constant
or can be changed on the fly in order to perform calculations with a different number of
channels. The following table shows the FFTlength code for a given transform length:
Number of Channels NB_CH code
8 00011
16 00100
32 00101
64 00110
128 00111
256 01000
512 01001
1024 01010
2048 01011
4096 01100
Table 2 : NB_CH codes