Check the micro. Most new 8051 will initialize in ALE generation mode *but* they can be disabled to reduce EMI.

In my choice of micro, the control is in address 8Eh, named AUXR, bit 0, named AO.

Also, if you clock via ALE, be mindful that the rate of pulses changes when you execute MOVX instructions. That might not be a concern, but you need to know.
I used ALE clocking with an external ADC on a prototype design once. I ran the driver out of internal memory and avoided MOVX instructions while the data was being converted. It not a bad design practice though I no longer use it in my designs.

aka j