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chava
Joined: 07 Sep 2003
Posts: 56
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| CCS produce a wrong code! |
 Posted: Sun Apr 04, 2004 4:04 pm |
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Hello
I wrote a simple function which receives a number, 0-256 (char) and makes a division to separate its ten digit and it's unit digit (example: 65=6 ten + 5 unit)
simple, isnt it?
here it is:
| Code: |
div_t x;
x=div(65,10);
righ=5;
midd=x.rem;
left=x.quot;
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dum, simple, every starting programmer should know that
but...
the values "righ","midd","left" are transfered to 3 different functions, each use a lookup table , to convert the value (0-9) to 7 segment format, then to portb.
simple.. yet...
when I run the code the variable "midd" gets the value of the variable "left", no metter what value I use.
Originaly the "div" function divided a variable that way:
char t;
x=div(t,10);
when it didnt work, I did "x=div(65,10)" to see if the problem lies in the div function.
I even built a division function of my own - but the result was the same.
Help me out here
Am I vaiolating some kind of CCS PIC "C" Compiler rull?
I even did
| Code: |
righ=displayed_val._fraction;
midd=6;
left=5;
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and again, "midd" gets the value 5 |
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Ttelmah
Guest
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| Re: CCS produce a wrong code! |
| Posted: Mon Apr 05, 2004 3:04 am |
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| chava wrote: | Hello
I wrote a simple function which receives a number, 0-256 (char) and makes a division to separate its ten digit and it's unit digit (example: 65=6 ten + 5 unit)
simple, isnt it?
here it is:
| Code: |
div_t x;
x=div(65,10);
righ=5;
midd=x.rem;
left=x.quot;
|
dum, simple, every starting programmer should know that
but...
the values "righ","midd","left" are transfered to 3 different functions, each use a lookup table , to convert the value (0-9) to 7 segment format, then to portb.
simple.. yet...
when I run the code the variable "midd" gets the value of the variable "left", no metter what value I use.
Originaly the "div" function divided a variable that way:
char t;
x=div(t,10);
when it didnt work, I did "x=div(65,10)" to see if the problem lies in the div function.
I even built a division function of my own - but the result was the same.
Help me out here
Am I vaiolating some kind of CCS PIC "C" Compiler rull?
I even did
| Code: |
righ=displayed_val._fraction;
midd=6;
left=5;
|
and again, "midd" gets the value 5 |
There are a lot of things wrong with your code.
First (which won't cause a problem with the value '65', but will latter), the 'div' function is only specified for _signed_ integers. Secondly (and hopefully just a typing error), an integer, can only hold 0-255, not 0-256.
These faults will 'bite you' latter, but should not cause your problem.
As written, the code should give left=6, midd=5, and righ=5. If this is not what you see, I have to then ask how you are actually 'checking' this. I have set up the same code to 'printf' the digits + 0x30, to an RS232, and this is exactly what is generated...
The correct sequence for a three digit conversion is:
x=div(65,10);
righ=x.rem;
x=div(x.quot,10);
midd=x.rem;
left=x.quot;
Which gives 065 for the three digits.
Best Wishes |
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chava
Joined: 07 Sep 2003
Posts: 56
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| I did too |
| Posted: Wed Apr 07, 2004 12:45 am |
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Hello
I also run this code but instead of printing the value on a 7 segment display I transmitted the data to a LCD, the result was as axpected:65.
but note: the program which I did with the LCD is for pic16f877a, and the one for the 7 segment is for 16f76
does that metter?
do you think that the pic16f76 is defected in someway?
Chava |
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