Tristate Logic and buses Flashcards
What is a tri-state?
A device with a third state which has a high impedance output (Hi Z)
What is a tri-state buffer
an input controlled switch with an output that can be turned on and off by an external ‘enable’ signal
How is the third state Hi Z achieved?
by switching off both pull-up and pull-down transistors
Define data bussing
when data is passed over sets of parallel interconnections
Define bus connection
high speed internal connections that send control signals
What are the applications of a tri-state buffer
-allows multiple logic devices to be connected to the same wire/bus without causing damage to data
-can be used to isolate devices from the data bus
What does Hi Z do?
stops current being drawn from the device and disconnects it from the data bus.
