TM4C123GH6PM: Which Inverter for Dual-SPI Emulating I2S?

Hello Bob, Bruno's suggestion for using vendor's ICs due to their exceptional functionality is your best clean option. Easy to select the right product. Alternatively, a 2N2222 with ~100 Ohm at the base (input) and 220~620 Ohm at the collector should also do the job.
John

P.S. Don't forget the not so optional 100nF capacitor from 3.3 to ground soldered very close to 2N22222

Let it be noted that REAL "I2S capable MCUs" dwell this earth. Such I2S "engines" always outperform "massaged into (some) compliance" lesser devices.

You may/may not explore this (superior) path - at least you now have a "fuller picture."

Your highlight of "Dual-SPI" may further exploit the many benefits of a proper I2S Engine.    (and further challenge the "massage job.")

Interesting enough, it seems that the predecessor of our beloved Tiva's had the dedicated hardware!

I came across this link (not sure if it will work for long):

www.ti.com/.../mculuminaryfeatures.tsp

Perhaps customers did not buy enough?

Which LM3S was this?    You may recall that predecessor firm (LMI) was without a chip foundry - employed a 3rd party - which was reported to "cause issues."    We're told (by our market "spies") that REAL "I2S Engine Equipped MCUs" sell (and perform) very nicely!

Let me first say that it never ceases to amaze me how helpful you all on this forum have always been.  Big thanks.  When I've found myself stumped on a technical detail while working on a TM4C123G project late at night and can't find my question asked before here or elsewhere on the web, I've posed my question here only to find a number of helpful responses to my question the following evening.  I indeed owe you gents a debt of gratitude.

Bruno Saraiva said:

Take a look at this application note, it has some good explanation about logic gates, and a nice selection chart:
www.ti.com/.../scyt129f.pdf I'm pretty sure you'll like to add this extra knowledge into your luggage.

Yes, indeed.  Just read the document and found it helpful in narrowing down my choices.  Thanks, Bruno.

John Piliounis said:

a 2N2222 with ~100 Ohm at the base (input) and 220~620 Ohm at the collector should also do the job.

P.S. Don't forget the not so optional 100nF capacitor from 3.3 to ground soldered very close to 2N22222

Thanks, John.  I will probably go the vendor-IC route as suggested, but after this post I plan to rummage through my stash of components and see if I can build this simple circuit (I know I have a couple of NPN transistors around here somewhere).  I am confused about the "not so optional 100nF cap" comment though.  I just Googled "2N2222 not gate" and the top three results all just show the transistor and two resistors.  Can you provide any additional info on the need for the capacitor?  Thank you.

cb1_mobile said:

Let it be noted that REAL "I2S capable MCUs" dwell this earth. Such I2S "engines" always outperform "massaged into (some) compliance" lesser devices. You may/may not explore this (superior) path - at least you now have a "fuller picture."

cb1 - Thanks for pointing that out.  I want to stick with my TM4C123G for now as I'm still interested in doing more projects with it, but I've definitely been perusing other development boards recently and I will certainly be looking for an MCU w/ I2S support when I'm ready for this next board.

Bob Crosby said:

Did that answer your question? While there are many options, if you are overwhelmed consider the SN74LVC1G04.
www.ti.com/.../sn74lvc1g04.pdf 

Thanks for the suggestion, Bob.  I'm not seeing this exact one offered in DIP package though, but on Mouser I'm seeing other SN74's in DIP that should fit the bill.  Gonna dig through those some and make a choice.

Bruno Saraiva said:

Interesting enough, it seems that the predecessor of our beloved Tiva's had the dedicated hardware!

I came across this link (not sure if it will work for long):

www.ti.com/.../mculuminaryfeatures.tsp

That is interesting.  I have to say, I have been a little surprised at the lack of audio related projects being done with the TM4C123 boards.  I am not sure if that is at all b/c they do not have I2S or if audio projects have always been in the minority so that's why TI removed I2S from these boards.  There are of course millions of things you can do with these boards and they are clearly quite popular judging by the number of projects out there when Googling and how active this forum is.

Greetings - as you acknowledge the assistance shown to you - we must (likewise) confirm that your posts are clear, well composed - and inspire response.   (always preferable to the (exhaustingly prep'ed/considered) "Does NOT Work!" ... which implies - somehow - that's (our) fault!)

Now - to avoid (another) claim of "blasphemy" - your search/find - then read/review of MCU equipped w/I2S Engine is likely to better highlight the key/critical "differences" between a "Real Engine" and an, "emulated" version.     Such may allow you to "tweak" your design - to best satisfy your unique requirements.

It proves always interesting to see how different (skilled) vendors attack implementation & function inventory.    Confining your curiosity to "just one" vendor deprives you of that "extra insight" - which may, "Speed, Ease, Enhance" your unique designs...    To best accommodate such (more diverse) methods/exploration - you may consider a, "more vendor inclusive IDE" (IAR, Keil) both available at no cost - but w/limitations - which should (still) enable (most) of your projects to succeed.      (and accept most any vendor's ARM MCU!)