While I understand quite well the excessive demands on Vignesh's resources, both time and money, it looks as though things are becoming muddled.

In order to sample a digital waveform of 1 MHz frequency, one has to sample at a minimum of 2 MHz. Within that half-microsecond interval, a microcontroller has to fetch the data, put it somewhere, increment the pointer to where he puts it, check to see whether he's done yet, then go back and do it all again.

It's not trivial to get around the horn in 10 instructions or so, though it might be do-able.

The problem arises when one realizes he has to figure out when to start and when to stop.

A useful logic analyzer has to be able to sample at twice the frequency at which his intended subject system operates. Since, in general, we limit most of what's done with our micro's to the operating frequency of common SSI/MSI logic, which is about 25 MHz. Well, that means a generally useful LA has to sample at up to 50 MHz in order to be generally useful. Now, that doesn't rule out special-purpose tools, and one has to go back and consider what the OP's (Vignesh's) original goal was. Maybe a fast microcontroller can manage what he originally wanted. I'd be interested in finding that out.

RE