朱铭雷的日记本

 Absolute Variable LocationVariables may be located at absolute memory locations in your C programsource modules using the _at_ keyword. The usage for this feature is:type _memory_space_ varia

XBYTEThe XBYTE macro allows you to access individual bytes in the external datamemory of the 8051. You may use this macro in your programs as follows:rval = XBYTE [0x0002];XBYTE [0x0002] = 57;