Yes initializing the stack in the Indirect RAM is a standard instruction that I use.

This almost became a dafult line in all the code that I did. There was this instance where the purchase guy came up and said 89c52 is out of stock and can we go in 89c51 ? Checked and found that the code was around 2.8K and said yes.

And the 89c51 never worked of course. Check hardware, doubt the MCU, blame it on bad luck till the realisation dawned ( 1 day later ) that the offending first line was MOV SP, #80H. !


Raghu