someone

• Aug 31st, 2006

 

a variable is to declared volatile , if the value of the variable is expected to change between two consecutive reads

eg: voilatile int i;

x

someone

• Aug 31st, 2006

 

a variable is to be declared volatile , if the value of the variable is expected to change between two consecutive reads

eg:

voilatile int i;

int x;

x = i;

printf("%d",x);

x = i;

printf( "%d",x);

the value of x would be different each time, i.e., the value of i has changed between 2 consecutive reads , maybe becuase of some interrupt...etc

since it is declared volative the compilers do no optimization

Techie

• Sep 2nd, 2006

 

Volatile is a keyword used to specify to the compiler not to optimize the access to the particular variable(defined as volatile). This is mostly useful in

 I)places the variable is used to refer to a pointer to device register.

2) If a global variable is set in an ISR and verified/accessd in a function.

3) If an address location is shared between different tasks.

tej

• Sep 4th, 2006

 

using volatile option doesnt put the variable in cache so there is will no time delay in updation of the register value hence when the variable is read frequently its declared as volatile