need help for configuration bits

[internetuser2k13]

what are the role of configuration bits.
i download for pic18f458. it contain the 2 pages for configuration bits.
is it good to write all config bit?

i see on some one blog.
he config bit in such a manners as it given below,

__CONFIG(1, OSCSDIS & XT);
__CONFIG(2, BOREN & BORV42 & PWRTEN & WDTDIS);
__CONFIG(3, CCP2RC1);
__CONFIG(4, DEBUGDIS & LVPDIS & STVRDIS);
__CONFIG(5, UNPROTECT);		// Chnage to CPA
__CONFIG(6, WPB);
__CONFIG(7, TRU);

can anyone explain these.??

__CONFIG(NUMBER, --- &----);

IN SIMPLE WORDS.

 

[FvM]

In simple words: Read the "configuration bits" chapter in device datasheet.

 

[wp100]

what are the role of configuration bits.
i download for pic18f458. it contain the 2 pages for configuration bits.
is it good to write all config bit?

i see on some one blog.
he config bit in such a manners as it given below,

__CONFIG(1, OSCSDIS & XT);
__CONFIG(2, BOREN & BORV42 & PWRTEN & WDTDIS);
__CONFIG(3, CCP2RC1);
__CONFIG(4, DEBUGDIS & LVPDIS & STVRDIS);
__CONFIG(5, UNPROTECT);		// Chnage to CPA
__CONFIG(6, WPB);
__CONFIG(7, TRU);

can anyone explain these.??

__CONFIG(NUMBER, --- &----);

IN SIMPLE WORDS.

Hi,

You should also find these files will help -
look up the pic18F458 .inc and pic18F458.temp files found in the Mplab ASM directories.

https://www.edutek.ltd.uk/Binaries/Datasheets/Micro/PICDeviceConfig.pdf

 

[bigdogguru]

what are the role of configuration bits.

The configuration register(s)/bits configure various features of the PIC, many of which cannot be configured during runtime.

is it good to write all config bit?

I generally good practice to configure all features of the device to a known state, otherwise features not specifically configured are in a default state and it is your responsibility to know this default state.

i see on some one blog.
he config bit in such a manners as it given below,

__CONFIG(1, OSCSDIS & XT);
__CONFIG(2, BOREN & BORV42 & PWRTEN & WDTDIS);
__CONFIG(3, CCP2RC1);
__CONFIG(4, DEBUGDIS & LVPDIS & STVRDIS);
__CONFIG(5, UNPROTECT);		// Chnage to CPA
__CONFIG(6, WPB);
__CONFIG(7, TRU);

can anyone explain these.??


__CONFIG(NUMBER, --- &----);

In the case of the PIC18F series there are multiple Configuration Registers, the NUMBER refers to the particular Configuration Register:

__CONFIG([B]4[/B], DEBUGDIS & LVPDIS & STVRDIS);

Each specific bit within a particular Configuration Register is referred to by an identifier which are bitwise AND'd (&) to form the require bitmask to set the bits within that specific Configuration Register.

__CONFIG(4, [B]DEBUGDIS[/B] & [B]LVPDIS[/B] & [B]STVRDIS[/B]);

These identifiers are typically available for review in the device specific header file, pic18f458.h, I usually include the device specific header file in the project window so that it maybe referenced while coding a particular device.

Each specific device typically offers a unique set of Configuration Register Bits, therefore as suggested by FvM, you need to read and study the device's datasheet for specific details pertaining to that device.


BigDog