I have a problem. I write a function in another c source file not main file, in this function nothing do, and I declare the function as extern. In main function I invoke it 200 times. However, the compiler does not use registerbank as counter. Why?
extern void func1(void); void func2(void) { unsigned char data i; for(i=200;i;i--); } main() { unsigned char data i,j; for(i=200;i;i--) // store i in 0x08 { func1(); } for(j=200;j;j--) // store j in R6 { func2(); } } the assembly code: C:0x0003 7508C8 MOV 0x08,#TMR2CN(0xC8) 19: { 20: func1(); C:0x0006 120025 LCALL func1(C:0025) 21: } C:0x0009 D508FA DJNZ 0x08,C:0006 22: for(j=200;j;j--) C:0x000C 7EC8 MOV R6,#TMR2CN(0xC8) 23: { 24: func2(); C:0x000E 120020 LCALL func2(C:0020) 25: } C:0x0011 DEFB DJNZ R6,C:000E
But that is true of both of them - so why did the compiler just put one of them in a Register...?
Or is it?
Maybe
unsigned char data i,j;
Is equivalent to
unsigned char data i; unsigned char j;
Sorry, I missed that bit.
Anyway, yes, I think you are correct ...
unsigned char *i, j;
is equivalent to:
unsigned char *i; unsigned char j;
Is it not???
I never use the first one, precisely because someone quiclky scanning the code might make a bad assumption.
Keil has somehow forgotten to specify if "data" binds to the left or to the right, but their own placement of the keyword does give an indication that it binds to the variable and not to the type, i.e. that it follows Andys example.
Compare with * for pointesrs, i.e.
unsigned char * i,j;
may look like
unsigned char* i; unsigned char* j;
but is actually:
As you might have guessed from my replies, I also missed it initially!
"I never use the first one, precisely because someone quiclky scanning the code might make a bad assumption."
Absolutely. Plus all the other good reasons equivalent to always using the braces on an 'if' even when not strictly necessary...