After reading over several forums and many posts, I created a custom union type struct for bitwise operations. I followed the p18f452.h header style for the format of the structure. If I just compile the files without invoking the actual variable in code, the code compiles fine. If I go to use the variable I get the error of
Quote:
MPLINK 4.22, Linker
Copyright (c) 2008 Microchip Technology Inc.
Error - could not find definition of symbol 'CMXCONTROL' in file './cmx.o'.
Errors : 1
|
A copy of my code snippet is provided below.
Code:
//Bit Control of the CMX's Control Register
extern volatile near unsigned char CMXCONTROL;
extern volatile near union {
struct {
unsigned PLLBW:2;
unsigned LEVRES:2;
unsigned DARA:1;
unsigned HILON:1;
unsigned CKDIV:2;
};
struct {
unsigned PLLBWLOW:1;
unsigned PLLBWHIGH:1;
unsigned LEVRESLOW:1;
unsigned LEVRESHIGH:1;
unsigned DARA:1;
unsigned HILON:1;
unsigned CKDIVLOW:1;
unsigned CKDIVHIGH:1;
};
struct {
unsigned PLLBW1:1;
unsigned PLLBW2:1;
unsigned LEVRES1:1;
unsigned LEVRES2:1;
unsigned DARA:1;
unsigned HILON:1;
unsigned CKDIV1:1;
unsigned CKDIV2:1;
};
} CMXCONTROLbits;
Code:
void TransmitTQB(unsigned char * pointer)
{
CMXCONTROL = 0x00;
CMXCONTROLbits.PLLBW1 = 0;
while(1);
}
Anyone know how to fix this error so I can invoke this way of accessing a variable?
28th January 2009, 01:12 PM
Error with Struct Building 
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Linear Mode
