Enable and Disable Functions

AND and OR gates can both be used to enable or disable a transmitted waveform.
For a two input AND gate, one input is the signal and the other input is the enable pulse.
The enable of an AND gate is high active. That is, when the enable is high the input signal will appear on the output.
When the AND gate enable input is low, the output will remain a constant low signal.
A two input OR gate can also be used with one input the desired signal and the other input is the enable.
The enable input of an OR gate is low active. This means that the output will be a copy of the input signal when the enable is low.
When the enable input of an OR gate is high, the output of the gate will be a constant high signal.