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C51S and movx/xdata

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

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  • To the best of my knowlege, the answer is no. The small model is what you choose, for example, if you have a stand-alone design with no external RAM. In selecting this mode, all variable declarations (unless explicitly cast to a different memory type) are of type "data". Thus, all code and parameter passing is performed using internal data memory.

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  • To the best of my knowlege, the answer is no. The small model is what you choose, for example, if you have a stand-alone design with no external RAM. In selecting this mode, all variable declarations (unless explicitly cast to a different memory type) are of type "data". Thus, all code and parameter passing is performed using internal data memory.

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