tri state

hardware A feature of some digital electronic devices

which allows a connector (pin) to either act as a normal

output, driving a signal onto a line, or to be "tri stated" -

set to a high-impedance ("high Z") condition. This allows

other outputs to drive signals onto the line. Often the same

connector also functions as an input when its output circuitry

is tri stated.

Tri-state outputs are typically used for the connection of

several digital circuits to a shared bus onto which any one

of them may output data for the others to input.

(1996-07-26)