What is ALE in 8086 in microprocessor?

Answer 1

ALE is a signal that means that the data bus contains the lower order address bus values. External hardware should strobe the data bus during ALE time, and lock it on the falling edge of ALE.

Answer 2

ALE stands for Address Latch Enable. Since lines AD0-AD15 are both address and data lines we need to make a distinction between when address lines are accessed and when data lines are accessed. Whenever address lines need to be accessed the Address Latch Enable line will be asserted (high/1). This tells the processor that we are sending an address to the rest of the system.

While ALE is for address access, DEN and DT/!R are used for data access and direction (since data is bi-directional), respectively.

Answer 3

The ALE pin in the 8085 is used to latch the multiplexed low-order address value from the address/data bus AD0-AD7.

The bus becomes valid for address sometime in the middle of ALE. Setup and hold time is guaranteed on the falling edge of ALE, and external logic is expected to latch that value. Somewhat after ALE - about a quarter clock cycle - the bus becomes the data bus and either floats for a read, or drives the data value for a write.

Answer 4

ALE, or Address Latch Enable, is a signal emitted by the 8086/8088 in minimum mode, or by the 8288 Bus Controller in maximum mode. ALE signals external bus logic that the data bus contains address data, and that it should latch it for later use in the read or write cycle.