The NAND gates can be used to design any digital function. Exclusive OR gates XOR are not so useful. If you are given a million XOR gates, you cannot design a single 2 input NAND gate using them. It is logically impossible.
There was a Fairchild effort called (?) CML (current-mode logic) that was kinda like ECL, but without inversion. So, all the logic was followers, no inverters and only wired-OR. Logic margin dropped at each stage. The way to make it work, is every three or so stages, you had to have a latch or flipflop, which had positive feedback and both polarities of output.
The 'gates' were useful as analog followers, but I never saw any logic systems built of that technology.
Integrated injection logic and majority logic were also interesting, but mainly just footnotes nowadays.
NAND is a pseudo-idempotent operator (A NAND A = not A) but, by inductive argument, all XOR-derived structures are either idempotent or non-idempotent.
That may be, but what made you even think of this? XOR gates are more transistor intensive than simple NAND or NOR gates. Why would you want to use XOR gates as your primary logic gate?
Rick C.
- Get 6 months of free supercharging - Tesla referral code -
It is as promising as, well, promised; it just got taken over by the easier-to-use CMOS.
I've applied IIL principles in a few analog circuits, for example a comparator and level translator with current consumption a fraction of an off-the-shelf gate drive IC.
IIL was said to allow transistors to overlap slightly but I don't remember anything else about it. What principles could you apply to a discreet circuit?
The OP didn't restrict the choice of XOR gate, or specify that ideal XOR gates had to be used. He said that it's impossible to make a NAND function out of XOR gates, so I did it.
Come on, play the game and give it a try. There are several other ways to do it, some even legal according to data sheets.
--
John Larkin Highland Technology, Inc
lunatic fringe electronics
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.