why this method did not work " if(a||b||c||d)

[mutthunaveen]

hi every one

I programmed a logic which uses 4 input pins

[Guest]

Hello,

Compiling your code under PCH 4.093 for the PIC18F86J16 produces the following:

[mutthunaveen]

ill check my compiler version and ill update to u

actually i coded for 4 pins in the port B with tris function

a=input(pin_b1);
b=input(pin_b2);
c=input(pin_b3);
d=input(pin_b4);

when i used a logic as if(a||b||c||d) { output_high(pin_a1); }

but if i enable these 4 pins to 1, the a1 pin is not going to 1

i changed the code to if(a==1||b==1||c==1||d==1) {output_high(pin_a1); }

then when i enable the put pins then the output pin a1 is going high.....
so here it is working

[RossJ]

I see no reason why your two if statements shoul behave any differently to each other. The only way to confirm if it is a compiler issue is to look at the generated assembly code (in the .LST file). Can you post the 'relevant' part of the .LST file as I did previously.

/Ross.

[mutthunaveen]

my compiler is installed in other PC.... ill go home evening.

ill update the ASM code today evening........

thanks for ur interest

[FvM]

[mutthunaveen]

[FvM]

[mutthunaveen]

So this is my entire code for program

[PCM programmer]

1. How are you testing this program ? Are you using a simulator ?
If so, which one ? Or is it a hardware board ? If so, have you ever
made this board do anything, such as blinking an LED ?


2. Describe the external circuits on pins B0 to B3.


3. Is this frequency value accurate ? 14 MHz is an unusual frequency:

[bkamen]

I think it's a little easier to some extent than this..

|| is a COMPARATIVE 'OR' requiring a complete expression output OR'd with another. ANY of those expressions being true controls the conditional.

where | is a logical 'OR' and the result of the OR controls the conditional.

If you have several single bit values (easier to work with), you can LOGICALLY 'OR' them together and that would work.


So

If A = 1 and B = 0

A | B == 1

So you COULD write (and I've done this)

[mutthunaveen]

So

If A = 1 and B = 0

A | B == 1

thanks bro
I'll try this today.........evening

and IO am using a PIC simulator oshonsofts latest trial version.

[FvM]

I just want to report, that the example application is operating correctly with PCM V4,093 and MPLAB SIM, thus I don't expect that there is a real issue with the code. I'm under the impression, that the shown V4.023 code is also correct, particularly the questioned "if (a||b ...)" line.

As a general remark, if rather outdated CCS C versions or third party simulators are involved with any assumed bugs, I would like this clearly mentioned from the start.

[bkamen]