Logic

Digital logic uses the boolean logic represented with high and low voltage values: depending on what voltage represents the /true/ value the logic is active high or active low.

With technology improvement the voltage ranges used to represent logic level has changed

Technology	L Voltage	H Voltage	Notes
CMOS	0V to 1/3VDD	2/3 Vdd to Vdd	Vdd = supply voltage
TTL	0V to 0.8V	2V to Vcc	Vcc = 5 +/- 10%

Combinatorial logic

• CMOS Gate Circuitry

Sequential logic

• Sequential Logic Circuits

TTL

• 1988 TTL Logic Standard Data Book

Tri-state logic

• Tri-state logic: Connecting multiple outputs together - 8 bit register - Part 2 video

Links

• Making logic gates from transistors video