in digital 1 is +5 or gnd?!!!?

Question

whats correct:
1=+5 & 0=gnd
OR
0=+5 & 1=gnd

Answer 1

This depends on the logic family employed. For "standard CMOS" which is common today, +5V is 1 and 0V or ground is 0. However, other systems use other voltages. Lower voltages are common today for a few reasons. 3.3V logic, for example, is widely used where 3.3V is a 1 (and 0V is 0). However, it is possible to have negative logic. In addition, some high speed systems like ECL use voltages like -1.75V for a 0 and -0.9V for a 1 (this allows transistors to stay out of saturation which makes for fast switching but poor noise immunity and difficult design).

Answer 2

It's a matter of convention. In the USA, a HI = 1 = Vcc; a LO = 0 = GND. I taught a few Chinese students who had a difficult time in my class, until I figured out that in China, HI = 0 and LO = 1.

Answer 3

If you are using 5V logic levels:



1 = +5V

0 = GND

Answer 4

usually 1=+5v .. and 0=gnd .. but it differs from system to another ... but always the voltage of logic one is higher than logic zero

Answer 5

1=+5 & 0=gnd

1=x & 0=0

normally....