This paragraph is from my SAB 80C537 user's manual:

"The main function of ALE is to provide a properly timed signal to latch the low byte of an address from P0 into an external latch
during fetches from external memeory. ...For that purpose, ALE is activated twice every machine cycle. The activation takes place
even if the cycle involves no external fetch. The only time no ALE pulse comes out is during an access to external data memory when RD/WR signals are active."