plz any one tell me how to work with timer.

#include <P89V51Rx2.H>
#define char unsigned char
#define int unsigned int
char timecount,move;
/********************************************************* The main function
**********************************************************/

void main()
{ P2=0xff; //Commissioner of all the lights
TMOD=0x01; //Timing / Counter 0 work in a way TH0=0x4C;
TL0=0x00; //50ms time constants
EA=1; //A total interruption
ET0=1; //Allow time / Counter 0 interrupted
TR0=1; //Start time / Counter 0 interrupted
move=0xfe;
while(1);
} /********************************************************* Interrupt service function
**********************************************************/
void Time0(void) interrupt 1 // using 0
{
TH0=0x4c; //50ms timing
TL0=0x00;
timecount++;
if(timecount==10)
{
timecount=0;
P2=move;
 move=(move <<1)|0x01;
if(move==0xff)
 move=0xfe;
}
}

in that program led was blink but i m not able to interface with 7 segment display. who could do this plz tell me

#include <P89V51Rx2.H>
#define char unsigned char
#define int unsigned int
char timecount,move;
/********************************************************* The main function
**********************************************************/

void main()
{ P2=0xff; //Commissioner of all the lights
TMOD=0x01; //Timing / Counter 0 work in a way TH0=0x4C;
TL0=0x00; //50ms time constants
EA=1; //A total interruption
ET0=1; //Allow time / Counter 0 interrupted
TR0=1; //Start time / Counter 0 interrupted
move=0xfe;
while(1);
} /********************************************************* Interrupt service function
**********************************************************/
void Time0(void) interrupt 1 // using 0
{
TH0=0x4c; //50ms timing
TL0=0x00;
timecount++;
if(timecount==10)
{
timecount=0;
P2=move;
 move=(move <<1)|0x01;
if(move==0xff)
 move=0xfe;
}
}

in that program led was blink but i m not able to interface with 7 segment display. who could do this plz tell me

That's still a bit of a mess!

Your code would be a whole lot easier for you & others to read if you take time to lay it out carefully; eg,

void main()
{
   P2  = 0xff; //Commissioner of all the lights

   TMOD= 0x01; //Timer/Counter 0 work in a way
   TH0 = 0x4C;
   TL0 = 0x00; //50ms time constants

   EA  = 1;    //A total interruption
   ET0 = 1;    //Allow time / Counter 0 interrupted
   TR0 = 1;    //Start time / Counter 0 interrupted

   move = 0xfe;

   while(1);
}

Any particular reason why you use #define instead of typedef?

Are you sure that those comments will really be meaningful when you look at this again in 6 months...?

Avoid the use of "Magic Numbers" - define constants with meaningful names.

That's a totally different question - so start a new thread.

But before you start a new thread, have you actually done any research into this?

Both the 8051 and 7-segment displays have been around for over a quarter of a century - surely you must be able to find something helpful that's been written down in all that time...?

If you have a specific question, then take time to explain what you've done so far, and where you're stuck...

Any particular reason why you use #define instead of typedef?

...

#define char unsigned char
#define int unsigned int
char timecount,move;

This "clever" use of #define will be problematic when you use it with pointers.

Jon

Jon;

This "clever" use of #define will be problematic when you use it with pointers.
Why?
Bradford

Jon was thinking about defining pointer types with #define instead of a real typedef:

#define uchar unsigned char
#define ucharp unsigned char*

uchar a,b;
ucharp ap,bp;

expands to:

unsigned char a,b;
unsigned char* ap,bp;

And suddenly bp isn't a pointer anymore.

This "clever" use of #define will be problematic when you use it with pointers.

Not even to mention that it'll f*ck up perfectly fine source code using things like "signed char" or "unsigned int".

If #define had been working for defining new data types, the C standard would not have contained any dedicated keyword - the language is minimalistic.

Duh! I failed to look carefully at the original post.
My bad! Thanks guys.
Bradford