In Reply to: I need help on two study questions!!! posted by Ernie on 06/02/00 at 4:14 PM:
: I am cramming for 3 electronic tests to be taken three days from today. In my (extremely abbreviated) study guides, there are two questions for which I cannot find the answer, no matter how hard I research. The first could be answered so simply - until one realizes that the simple answer can also pertain as easily to the NOR gate. Any help I may be able to get ASAP would be DEEPLY appreciated. My head is throbbing with everything from logic circuits to extensive miscellaneous information on computer processing, peripherals, and general electronics.
: 1) EXPLAIN WHY THE NAND GATE IS USED AS A UNIVERSAL GATE.
: 2) EXPLAIN THE CONSTRUCTION AND CHARACTERISTICS OF AN IC RAM.
: I would appreciate a short E-Mail if you know the answer to either of these questions: firstname.lastname@example.org
: Thanks a bunch!!!
In short, all logic functions, NOT, AND, NAND, OR, NOR, Exclusive OR and Exclusive NOR can be synthesizied from NAND gates. It's sometimes considered useful to have only one logic circuit to do everything, but it's not a universal practice. Also, the same statement COULD also be made about NOR gates.
Static RAM cells are bistables or flip-flops. Dynamic RAM cells are different; they store bits in charged capacitors which require refresh cycles to keep their data valid.
I hope this helps!
John Dunn - President