DIGITAL ICs ARE 2-STATE DEVICES. ONE STATE IS NEAR 0 VOLTS OR GROUND (LOW OR L) AND THE OTHER IS NEAR THE IC’s SUPPLY VOLTAGE (HIGH OR H). SUBSTITUTE 0 FOR L AND 1 FOR H AND DIGITAL ICs CAN PROCESS INDIVIDUAL BINARY DIGITS (BITS) OR MULTIPLE BIT WORDS. A 4-BIT WORD IS A NIBBLE AND AN 8-BIT WORD IS A BYTE.
THE BINARY SYSTEM
IT’S VERY HELPFUL TO KNOW THE FIRST 16 BINARY NUMBERS. IF 0=L AND 1 = H, THEY ARE:
NOTE THAT LLLL (0) IS AS MUCH A NUMBER AS ANY OTHER NUMBER.
LOGIC GATES
LOGIC CIRCUITS ARE MADE BY INTER-CONNECTING TWO OR MORE OF THESE BASIC LOGIC GATES: