On 1/24/2006 at 8:00 PM Jim Battle wrote:
No, my memory was that it used 4-state cells to encode
two bits per cell
in the microcode rom. Rather than transistor/no transistor to represent
0/1, it used no transitor = 00, weak transistor=01, normal
transistor=10, strong transistor=11, or something akin to that.
Quite correct! I found a couple of citations in the IEEE online archives.
My muddled mind had it as (zero, one and neither). I understand that some
flash memories also use 4-valued (quaternary) memory cells "under the
hood".
I wonder if eventually multi-valued logic may have its biggest potential
not in speed or conservation of chip space, but rather in decreasing the
number of I/O pins.
Cheers,
Chuck