Since Keil (as opposed to some other compilers) do not supply the library in source, I have a question: I am tasked with debugging some glitches in a very strange design: External memory is used and ALE is disabled. To access external RAM one must latch the low address in an external latch by toggling a p1 pin before executing external RAM access (movx). My question thus is: do the routines in C51S EVER execute movx. I have no possibility of replacing thousands of hardware units, and already have the next version concept so I need the above question answered. Thanks in advance Erik
I did a little more checking, and in the Phillips versions of 8051, if ALE is disabled, it is still activated when a MOVX instruction is executed. It is turned off for any on-chip access.