1) Ajar171 thank you for the New Year's wishes, may we be successful.
The next questions may be lame, but I think that you need to know the block structure of the tool to use it well and interpret data (errors). I am interested in the problem of trigger(s) and memorizing samples from ADCs (DFSDM). Synchronization of these blocks, because I see a big hardware and software problem here (not eliminated by the programmer of this device).
2) ad3 "
All filtering, averaging is done in HW, see the DFSDM block diagram (ignore the serial and parallel ADC part, the data is coming from the bus) " I attached your drawing and led in Red the processing in Oscilloscope mode. In Blue DMM. I did this to make sure I understand you correctly. And I have further questions:
ad3.1 Where is the 128 kB of memory, I understand that it is a circular buffer (filled with DMA packets, where is the grouping of this data)?
ad3.2 Does HW supervise this (it has to, but how?
)?.
ad3.3 I mean how is the data in this memory synchronized with time (is time measured successively by adding the ADC sampling time value?).
Ad3.4 Is this buffer filled all the time even when no trigger has occurred (I think so)
Ad3.5 How does HW know (synchronize) the trigger occurrence… but this problem after explaining how the trigger circuit works.
3T) In your list you wrote a few things about triggering in this device:
3T.1 You wrote that this is software triggering. Then that there are simple comparators there. How is that?
3T2 I imagine that the comparator detects exceeding the threshold (UweTrig). The HW circuit has a setting on the pin to interrupt the transition from state 0 to 1 or vice versa. And then it is necessary to precisely determine the current position of the data recording in the 128 kB buffer, i.e. precisely synchronize: the data positions at the time of the trigger. Then determine how many ADC samples must be saved after the trigger (here the position of the time trigger) to interrupt the measurement at the right time. If this time is too long, then the data is overwritten at the beginning of the samples, if the old data is too small. And this sometimes happens in the meter. This very very difficult for hardware and SW.
4) Here I would like to describe my observations of the measurement in the oscilloscope mode, one channel, single trigger. I know that you do not care how this software works, but if you specified the sampling frequency (maybe the amount of data), it would be a sure source of knowledge for us. In addition, I always think that a person can learn from the mistakes of others.
4.1 The oscilloscope with small time bases from 10 ns to 10 us always records 128 kB samples with the highest possible frequency (I think so). This gives an approximate recording time of +- 300 us (time trigger in the middle). You can see this by pressing the hold key, and then increasing the time base. Picture 2 and 3.
4.2 The problem with this meter is as follows:
4.2.1 when several triggers occur in a row, it incorrectly determines the data copying positions from the buffer;
4.2.2 if the trigger is triggered before the time of 320 us, the data is initially zeroed.
4.2.3 when the time base is less than 500 ns, there is a shift between the trigger position and the data (this situation can also occur on other bases).
4.2.4 I generally stopped going below 1 us with the time base, because the same data is recorded anyway, which I can later see in Hold mode.
AD4 "
280MSPS is electrically possible only on channel 1 (it is still 140MHz ADC clock, but with a 180° clock phase shift)", does this mode require the same signal to be applied to the CH2 ADCs input or is it done internally
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