PIC12F508 : OPTION Register issue ( Using HI-tech Compiler)

[chetan.rmit@gmail.com]

Hi building a trigger circuit, so I'am required to generate continuous on-off pulse from the Microcontroller. I' am using Internal clock through the following instruction :

__CONFIG(MCLRDIS & WDTDIS & UNPROTECT & INTRC);

Then I tried to configure Timer0.

So I did the following.

T0CS = 0 //Transition on internal instruction cycle clock, FOSC/4
PSA = 0 // Prescaler assigned to Timer0

PS0=1;PS1=1;PS2=1 // For maximum prescaler of 1:256

( Used the above, from the header file pic125xx.h as:
/* OPTION bits */
#define GPWU (1<<7)
#define GPPU (1<<6)
#define T0CS (1<<5)
#define T0SE (1<<4)
#define PSA (1<<3)
#define PS2 (1<<2)
#define PS1 (1<<1)
#define PS0 (1<<0)
)


But the compiler threw up an error , as :

Error [202] C:\Users\Chetan\Desktop\Yogesh\pulse.c; 10.11 only lvalues may be assigned to or modified


Couldn't understand where I went wrong. I' am new to Hi-tech compiler and trying to get used to it. Any kind of help will be greatly appreciated and would be of lot of help.



Thanks
Regards
Chetan Gowda

 

[Pommie]

You are trying to give a constant a value which is not allowed.

Just write the whole register by doing, OPTION = 0b11000111;

Or, to set the prescaler do OPTION |= 0b00000111;

And to clear TOCS do OPTION &= ~TOCS;

HTH

Mike.