Q5Microprocessor and Microcontroller

The Address Latch Enable (ALE) is a critical, positive-going timing control signal generated directly by the 8085 during the very first clock cycle ($T_1$) of every machine cycle. It explicitly commands an external latch IC (like the 8230) to instantaneously capture and hold the lower 8-bit address present on the multiplexed $A{D}_0-A{D}_7$ lines, freeing those physical lines to act as the Data Bus in subsequent clock cycles.