Digital clock program using AT892051

because RETI shud always be used after an interrupt routine in the end.

because RETI shud always be used after an interrupt routine in the end.

More likely you neglected to include the closing brace in your post.

No. if i give the RETI instruction before the brace, it gives an error.

IB Shy Posted"Started to reformat your text, but decided there were more important things to do."

I started trying to decipher your scribbles and decided there were more important things to do

DO post some code

Erik

code: something that is indented and commented
text/scribbles: something unreadable

Yes, because you have got it wrong.

Look at the manual regarding interrupt functions:

http://www.keil.com/support/man/docs/c51/c51_le_interruptfuncs.htm

what's wrong with it? Can you please say what it is cos i need this project to be submitted asap

I advised you of something that is wrong and I told you where to look.

There are almost certainly other faults, but I/We don't have the time to decipher your scribbles.

I understand the value of your time and I'm very thankful to you'll for looking into my bug. I though regret that my code is scribbled at your end cause over here I have written it in proper language without any srcibbling

The code is hard to read. Both because it wasn't correctly posted, and because you have made it very complicated.

If you program in C - why do you then think you should have an assembler instruction somewhere in the code? Have you ever seen any Keil C program with a RETI for an interrupt handler? Please in that case show a link.

You have off-by one errors - how will you get your clock to display the 7:59:59? When secnds reaches 59, you reset to zero - should wait to 60. Same for the other variables.

You seem to have multiple blocks:

if (8>i) {i++; ...}

How many times can i be incremented in a single visit to your ISR?

What is the full range you expect Dispcount to run to until restarted? You have Dispcount declared as unsigned char but are trying to store values way outside the numeric range. And should Dispcount really be overflowing? I would have thought that the display output should happen once/second, meaning your state machine should restart every 1000ms.

And it isn't easy to read the code when you have many if() statements processing Dispcount in varying order - sometimes a lower value gets tested after a higher value.

When you test an integer for a large number of different values, there is a specific language construct - switch statement - available. It was added for a purpose. Can you guess what purpose?

There are other errors too. You really have not spent much time looking at your code and tried to single-step it in your head. You post to a forum to ask for help unless you have already made sure that you have caught all the easy errors? Because you think that a prfessional developer who have this as occupation would send out all his code on forums to find someone to catch all the errors? But who would the legendary/magicall beings be who reads forum posts and catches trivial errors if the developers themselves don't spend time catching them?

Another thing - if this clock is battery-operated, it would consume 100% CPU power and hence a lot of batteries by the main loop that is constantly converting the individual time components into a string. Is it meaningful to try to build this string hundreds or thousands of times every second?

So you simply need to learn how to post code correctly.

Did you not read Andy Neil's response on your duplicate thread?

www.danlhenry.com/.../keil_code.png

Talking about scribbling.

Can you - without looking at the datasheets or datadeclarations of your program - tell what the following code does?

if (Dispcount == 89) {
    CS1 = 0;
    CS2 = 0;
    CS3 = 0;
    CS4 = 0;
}

Will you also be able to do it six months from now?

Is there a reason why you don't believe comments belong in source code? Maybe "The code was hard to write, so it should also be hard to read"?

How much do you think it "speeds up" your debugging, to have source code without comments?

Thanks Mr.Westermark for your thoughts on my program. The thing is that I'm new to Keil C, so finding it difficult in the beginning to cope up with it.
As you said, the shouldn't be used in this program?
And is it that my variable minutes, seconds must have 60 counts even if i use (Minutes>=59)?
I don't know how many times i can be incremented in the ISR. It must be incremented only once? if yes then where in particular in my program.
and my last question, what should be Dispcount declared as?

I hope this isn't a scribbled one.

#include <AT892051.H>
#include <stdio.h>
#include <intrins.h>

sbit PIN_P10=P1^0; /* Character to be transfered through thisbit in parallel*/
sbit PIN_P11=P1^1; /* Clock*/
sbit PIN_P12=P1^2; /* Latch*/
sbit CS4=P1^3; /* 1st 7-segment Display*/
sbit CS3=P1^4; /* 2nd 7-segment Display*/
sbit CS2=P1^5; /* 3rd 7-segment Display*/
sbit CS1=P1^6; /* 4th 7-segment Display*/

unsigned char DataWrite;
unsigned char _crol_(unsigned char Temp,unsigned char DataWrite);
char Display_Buffer[6];
unsigned char Dispcount;
unsigned char mscount;

int Hours=1;
int Minutes=0;
int Seconds=0;
int i=0;
char Temp;

code unsigned char Lookup[11]=
{ 0xEE,0x28,0xCD,0x6C,0x2B,0x67,0xE7,0x2C,0xEF,0x2F
};

void main()
{

TMOD=0x01; TH0=0xF8; /* Initializing timer0 for 1ms*/ TL0=0x30; IE=0x82; TR0=1;

do
{

sprintf(Display_Buffer,"%02d%02d",Hours,Minutes); /* converting integer into character*/

}while(1);

}

void Timer0(void) interrupt 1 /* ISR */
{ TF0=0; TR0=0; TH0=0xF8; TL0=0x30; TR0=1;

{

Dispcount++; /* Dispcount is used to refresh the Hours and Minutes on the LED*/ if(++mscount>=1000) { mscount=0; Seconds++;

} if(++Seconds>=59) { Seconds=0; Minutes++;

} if(++Minutes>=59) { Minutes=0; Hours++;

} if(++Hours>=12) { Hours=1; } }

{ if(Dispcount==29) /* This code is for refresh rate of LED1*/ { CS1=0; /* CS1, CS2, CS3, and CS4 are Rspective LED's Of HH:MM*/ CS2=0; CS3=0; CS4=0; } if(Dispcount==30) {

DataWrite=Lookup[Display_Buffer[0]-0x30];

}

if(8>i) /* For a byte to be read by the port pin*/ { i++; if (Dispcount==32) { Temp=DataWrite; } if (Dispcount==34) { PIN_P11=1; /* clock is set high*/ }

if (Dispcount==36) { PIN_P10=Temp^7; /* Taking MSB one at a time, the loop continous till all 8-bits are sent to the portpin*/ } if (Dispcount==38) { PIN_P11=0; /*clock is made low*/ } if (Dispcount==40) { DataWrite=_crol_(Temp,1); /* bits are rotated left*/ } PIN_P12=0; }

if(Dispcount==48) { CS1=1; /* Chip 1 is selected i.e; for tens unit of Hour*/ }
}

{ if(Dispcount==49) { CS1=0; CS2=0; CS3=0; CS4=0; } if(Dispcount==50) {

DataWrite=Lookup[Display_Buffer[1]-0x30];

}

{

if(8>i)

{ i++; if (Dispcount==52) { Temp=DataWrite; } if (Dispcount==54) { PIN_P11=1; }

if (Dispcount==56) { PIN_P10=Temp^7; } if (Dispcount==58) { PIN_P11=0; } if (Dispcount==60) { DataWrite=_crol_(Temp,1); } PIN_P12=0; }

}

if(Dispcount==68) { CS2=1; }
}

{ if(Dispcount==69) { CS1=0; CS2=0; CS3=0; CS4=0; } if(Dispcount==70) {

DataWrite=Lookup[Display_Buffer[2]-0x30];

}

{

if(8>i) { i++; if (Dispcount==72) { Temp=DataWrite; } if (Dispcount==74) { PIN_P11=1; }

if (Dispcount==76) { PIN_P10=Temp^7; } if (Dispcount==78) { PIN_P11=0; } if (Dispcount==80) { DataWrite=_crol_(Temp,1); } PIN_P12=0; }

}

if(Dispcount==88) { CS3=1; }
}

{ if(Dispcount==89) { CS1=0; CS2=0; CS3=0; CS4=0; } if(Dispcount==90) {

DataWrite=Lookup[Display_Buffer[3]-0x30];

}

{

if(8>i) { i++; if (Dispcount==92) { Temp=DataWrite; } if (Dispcount==94) { PIN_P11=1; }

if (Dispcount==96) { PIN_P10=Temp^7; } if (Dispcount==98) { PIN_P11=0; } if (Dispcount==100) { DataWrite=_crol_(Temp,1); } PIN_P12=0; }

}

if(Dispcount==108) { CS4=1; }
}

if(Dispcount==121) { CS1,CS2,CS3,CS4=0;

}

}

RETI;

Yes I want to learn about how to post a source code and where

 is used cause I did not get a clear picture of the example given

So, this is a school assignment, then?

"The thing is that I'm new to Keil C"

But your school knows that - and they expect that, at this point in your course, you should have learned enough 'C' (most of it is not Keil-specific) to enable you to complete this task.

Perhaps it's time to review your course notes, textbook, etc...?

There is no need to "hope" - the 'Preview' button will show you!

Other than "hoping" what specific steps did you take to ensure that it's not "scribbles"?

* did you, as instructed, follow the directions on how to post source code?

* did you, as instructed, take time to carefully comment your code?

* did you, as instructed, take time to consider carefully the data types required by your variables?

* did you, as suggested, take time to consider what 'C' language construct is appropriate to testing an integer varialbe for one of a number of different values?

etc, etc,...