使用xdata遇到的问题

linkin8834

我写了一段代码，然后在KEIL开发环境下使用了不同的MEMORY MODEL: SMALL和LARGE(variaties in xdata)。使用SMALL时功能正确，但是用LARGE时却无法实现正确的功能。而且我将某些变量定义为xdata，功能也无法实现，编译倒能通过。请问问题何在？xdata是不是一定要间接寻址的？

hominidlee

There are 3 memory models available for programs using the Keil C compiler – SMALL, COMPACT and LARGE. In the SMALL memory model the default storage location is the 126 Bytes of internal memory while in the LARGE memory model the default storage location is the externally addressed memory. The choice of which memory model to use depends on the program, the anticipated stack size and the size of data. If the stack and the data cannot fit in the 128 Bytes of internal memory, then the default memory model should be LARGE; otherwise, SMALL should be used.

linkin8834

谢谢！已经解决了，我把一些变量定义到了XDATA中去，然后还是用small，功能正常了。