Address Latch Enable pin (ALE) tutorial

Question

Based on the following ALE waveform, what are the data that flow through AD0-AD7 at cycle T3 until T4.

Answer

AD-AD7 can carry both Address and Data type of data. ALE is the pin that indicate what is the type of data that currently flow through AD-AD7 pin.

ALE = 0 ( address latch disabled --> data )
ALE = 1 ( address latch enabled --> address )


At cycle T3 until T4 ALE=0 therefore the data that flowing through AD0-AD7 is Data.