/*******************************************/ /*Name：Main Function */ /* Memory model: LARGE */ unsigned char Temp; unsigned char *pTemp; void func(void); void main(void) { unsigned char i = 6; pTemp = &Temp; *pTemp = 98; func(); i = *pTemp; } /*************************************************/ /*-------------------------------------- compile following program to assembly , then link with the main function.No Error! But the " i " cannot get the number "0xdd". Why and how to chang the assembly . please help me,thank you.! ------------------------------------------*/ #pragma src(MYPTR.A51) large extern unsigned char *pTemp; void func(void) { *pTemp = 0xdd; }
Is it possible that the compiler has optimized the variable i out? Since the value assigned to it is never used the compiler has the right to do so. You can try and disable optimizations or use the variable i somehow. Anyway, why not have a look at the generated code? Regards, - Mike
When I had compiled in SMALL memory model,it was OK. But when in LARGE memory model,the compiler generated wrong code for "i = *pTemp;". Is this a bug in Keil? -Bird
Are both files compiled for the same memory model? Jon
"the compiler generated wrong code for 'i = *pTemp;'." In what way was it "wrong?"
If you have optimizations on, doing absolutely nothing IS correct for "i = *pTemp;". Does your code fail if you compile it with no optimizations?
Thanks very much!Thanks Mike,Thanks Jon! Thanks all of you! My program is OK.