Hello Everyone,
I wonder whether anyone could shed some light on the meaning of "clock_times"
for me in the context of Rx_Use_Clock_Input.
The clock_times section on pg. 229 includes the following statements:
"The clock times are exactly symbol_time/2 before the input data signal is
sampled."
and
"Each valid value in the clock_times vector shall be used to sample the output
waveform by adding to it symbol_time/2"
The section on Rx_Use_Clock_Input (on pg. 253) only provides a brief reference
to
the clock_times input of the GetWave function without further detail related to
my
question:
"Specifies the content of the Data Rx AMI_GetWave clock_times input supported
by the model."
Let me ask my question with an example. Consider an clocked Rx AMI model which
is operated in the "Wave" mode. In this case the (unstated) assumption seems
to be
that the waveform is a difference signal, and the clock ticks occur at the zero
crossings
of that difference signal. (It would be nice to state that the assumption is
that this is
a difference signal, otherwise we would need to provide parameters for threshold
values too)... Aside from that, what clock times should the Rx AMI model
return to
the EDA tool in the clock_times vector (output)? The times of the zero
crossings, or
(zero crossings) - (0.5 * UI)?
Now change the above example so that there is a clock Rx AMI model that converts
the waveform into clock times and EDA tool passes those values into the data Rx
model's
clock_times vector. Is the clock Rx model supposed to just output the times of
those
zero crossings for the data Rx model, or is it supposed to generate values as:
(zero crossings) - (0.5 * UI)?
Keep in mind that "clock_times" is defined as:
"The clock times are exactly symbol_time/2 before the input data signal is
sampled."
If the clock Rx AMI model would generate zero crossing times for the data Rx
model's
clock_times input vector, isn't it generating "sampling times" instead of
"clock times"?
And, if this were the case, would the data Rx model need to convert these
sampling times
to clock times for the EDA tool by subtracting 0.5 * UI from each value before
putting
them into the clock_times vector (output)?
Either way, what was the intent of BIRD204/209? I feel that this needs to be
clarified
(unless I am missing something obvious)...
Thanks,
Arpad
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