For example gigabit ethernet uses five voltage levels for data signalling.

 

I'm pretty sure the TS is not talking about signaling. Multi-level signaling has been around pretty much since day one. I believe the TS is talking about processors that fundamentally utilize greater than base-2 operations such that all signals within the processor are multi-level.

 

Sure. The Intel x86 parts and the ARM parts all have multiple voltage levels. Just have a look at the datasheets. Typical levels you might find are:

1. +5VDC
2. +3.3VDC
3. +2.7VDC
4. +1.8VDV
5. +0.8VDC

The higher voltages are used for interface to the I/O, and the lower voltages are used for the processor core.

EDIT: Sorry, while the above is true it does not answer the question. In communications is where multiple voltage level signaling is used. In terms of core logic for a processor there are almost no examples of multi-level logic. What is actually happening is voltage translation to lower levels as you approach the processor core. This is done primarily for power dissipation considerations.

Indeed....and some very robust systems use tri-state logic: -1,0,+1.

 

Indeed....and some very robust systems use tri-state logic: -1,0,+1.

But that is still just carrying binary information.
The "off"state is for bus applications to allow other chips to address the bus.

 

Indeed....and some very robust systems use tri-state logic: -1,0,+1.

Could you give an example of one that you have in mind? How is the tri-state information processed? What are the definitions of the fundamental operations on it?

 

Indeed....and some very robust systems use tri-state logic: -1,0,+1.

I think you misunderstand the nature of what is actually a misnomer.

 

I don´t see a problem with using true ternary or higher base logic based computations, the background behind the arithmetical and logical operations will work just about the same as binary. What I see as a problem is the hardware implementation where I doubt any contemporary cmos process could be readily used, and I fail to see how a three state logic could be more robust than a two state, given the same range of voltage levels - in terms of SNR etc the less levels you have the more your signal is immune to noise and interference.

 

Sound propagation is a series of pressure waves in a mechanical medium (gas or solid) whose amplitude represents the signal amplitude.
Neural impulses are a series of electrical (digitized) pulses that travel down nerve fibers whose frequency (not amplitude) is the encoded signal amplitude (for example, the more pulse per second down a pain nerve, the more pain you feel).
They are not at all alike.

I was thinking sound as in analog waveform, as opposed to digital, tone being frequency modulation.