multirate and DC source
Hello everybody,
i'm using the multirate blocks on adau1452 and i noted that the project cannot be compiled and stops with an "invalid samplerate detected" if i use any DC source.
More in detail, it seems that every block following the downsampler, correctly, acquires the new samplerate, except
any DC source eventually connected to the blocks following the downsampler.
If then i manually change the DC source samplerate, the graph compiles correctly.
First question: is this a bug ?
Second question: has it any sense, for a DC source, so a constant number , to have a sample rate specified?
Third question, but i don't know if this is the right place to ask: could be implemented, on the sigmastudio's graphical editor, a way to search the schematic diagram ? If you get any error, finding the faulty block or connection can be tedious, expecially on large projects. The best way could be to have the error message clickable, so clicking it, it can show directly the erroneous part on the graphical editor.
Thanks.
Tom
Audio Signal Processors
adau1452
SigmaDSP Audio Processors
Hi Tom,
Even though a DC source seems like it should be "rateless", all blocks within SigmaStudio still must have a specified sample rate, due to chip architecture. So, this is not a bug, even though it seems a little unnecessary.
As for the error message highlighting the faulty block, I'll pass that idea along to our software team! I agree that it would be a useful feature.
Regards,
Tyler
Hello Tom,
Let me add to Tyler's response that all sources in SigmaStudio must specify a sample rate and that gets propagated down to all the cells that are connected to this source. This makes sense for oscillators and other function generators that need a sample rate to function but you are right it is not needed by the DC cell itself/ However, blocks downstream may need the information. So this is a requirement for all sources to supply a sample rate.
Good suggestion about the error reporting.
Dave T
Hello Dave and Tyler,
thanks for answering.
Ok, all blocks must have a sample rate, but it seems that the sample rate change due to an up/downsampler is not well "propagated" to each different-rate block.
If you, for example, connect a downsampler to an adder block input and the second adder input is connected to a dc source, you get the error, because the adder gets the scaled sample rate, but not the dc source:this is the reason why i think it is a bug.
As i wrote, if i change the DC source samplerate manually, everything works fine, also if the DC source is then shared with other different samplerate blocks.
It seems like the DC source sample rate is checked, and error reported, only if it is related to a multirate block and this is weird.
Bye
Tom
Yes, I would also find a "go to error" search quite useful when debugging large projects. Sometimes in the rush of trying various constructs, a misconnected block ends up underneath others -- especially tough to find.
Please log in to reply.