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is there easy way to know which decimation phase got selected?

Started by bharat pathak September 30, 2010
Assume that i am doing decimation by 64, first by filtering and
then throwing. This is implemented the same way in RTL and C.

But there might be a data shift in input. Maybe one more or one less.
This would essentially be same as selecting a different phase of the
filter. Assuming that the input I feed is sine wave, is there a
way to know which phase got selected? Observability points are only
outputs.

-Bharat

On Sep 30, 9:45&#4294967295;am, "bharat pathak" <bharat@n_o_s_p_a_m.arithos.com>
wrote:
> Assume that i am doing decimation by 64, first by filtering and > then throwing. This is implemented the same way in RTL and C. > > But there might be a data shift in input. Maybe one more or one less. > This would essentially be same as selecting a different phase of the > filter. Assuming that the input I feed is sine wave, is there a > way to know which phase got selected? Observability points are only > outputs. > > -Bharat
A data shift: 1) from the beginning? OR 2) dropping or repeating a sample after the filtering has started? OR 3) dropping or repeating a sample after the transient has died out? Would this happen once or multiple times? Dirk