• In addition to the 0 and 1 logic levels, three-state, tri-state, or 3-state logic allows an output or input pin/pad to assume a high impedance state, thereby removing the output from the circuit.
• Many electrical and microprocessor circuits employ the Tri-state Buffer because it allows numerous logic devices to be connected to the same wire or bus without causing data loss or damage. As an example, consider a data line or data bus that is connected to memory, peripherals, I/O, or a CPU.
• Most bus drivers, registers, and flip-flops in the 4000 and 7400 series, as well as many others, use three-state logic. Many integrated circuits, such as microprocessors, RAM or memory, as well as many chips used in peripheral devices, use three-state logic internally.

Read More: Features of Microprocessor