I awoke this morning with the thought that those three and four capital letters in the upper left hand corner of the diagram could be significant. I went to page 8 then 9 and 10. That's it. What does TQFP and QFN stand for? At second glance I see one is for a printed circuit and the other is for a socket. Details! Details!

Thank you for the PULSEIN suggestion. I think that is what I need.

I have not prototyped since 1973ish and then I had a technician to physically build the circuits. I am hesitant. First I should get the three power supplies (7.2V battery pack, 6.0V battery pack, 5.0V USB) installed, regulated and grounded. I wish I had an oscilloscope.
(Oh for the good old days of upright analog Tektronix.) You'd think they'd be on the yard sale/antique market.

I shall keep you all in touch.
Thank you for being there.

Ken