bitwise operator operations

[MCUprogrammer]

Hi everybod;

How bitwise operator operations work with this code I wrote? Can someone explain this with an example? So these hex numbers are written as binary. What are the next steps? Can you help with this written code and explain the logic? Thanks.

[Ttelmah]

Forget about binary hex etc.
All values inside the chip are binary. Decimal, hex etc., are just
'representations'. Other ways of writing the values.

[PrinceNai]

AND gives "1" ONLY when both corresponding bits are "1" and it is used to clear some bits

So if your variable is:

11011111 and you want to clear last 3 bits, you AND it with
11111000 and you get
-----------
11011000 as a result. Only the last 3 bits changed, others are as they were

OR on the other hand gives "1" when AT LEAST ONE BIT is "1" and you can use it to set some bits in your variable.

10100000 and you want to set last 3 bits you or it with
00000111 and you get
-----------
10100111 as a result

[PrinceNai]

As Ttelmah said, all the variables live as binary inside the PIC. When writing a program, you can use whatever notation you want, bin, hex, dec. At least for me, when doing any kind of bit manipulation with those operators, binary is the easiest because you can see the result directly.

[MCUprogrammer]

input_e() 7 button inputs;

& bitwise operator
0xDF = 11011111
input_e() = 00000101 information came In this case, value variable result
The value 00000101 = 5 occurs.
is it correct?
-------------------------------------------------------------------------------
The value 9 is passed as an argument to the func(9) function.
/* my understanding for this code;
output_value = input_c() & 0xF8; //read PORTC, clear C0, C1, C2 and preserve C3 to C7 */
He studied PORTC. Send '0' to first 3 bits of 8 bits and '1' to all subsequent bits to clear C0-C1-C2. At first when input_c() reads all pins are 0.
0xF8 = 11111000
input_c()= 00000000
output_value = 00000000. Is it true ?

/* what I understand for this code
output_value |= (value & 0x07); //update only C0, C1, C2
*/
output_value |= (0000101 & 00000111); func(5) was sent.
When I put (value & 0x07) into bitwise processing, the result = 00000101
what happens next? How to proceed next. And how does the value of 5 go to the output portc and light the output leds.

In addition, only transactions related to related entries &,| How do you decide to use it?
So for example to update | bitwise operator, am I using the & operator to preserve the value of other I/Os?
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MCUprogrammer
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[PrinceNai]

The results seem correct for your values. Once again, when using AND you can only set (or update, as you put it) some bits of the variable to 0. Never to 1. Unchanged or 0.

When using OR, you can set some bits to 1 and never to 0. Unchanged or 1.

So if you want to force some bits to zero, use AND.
If you want to force some bits to one, use OR.

You have loads of bitwise calculators on the web to try and train with some numbers and check the results.

As for outputting the result, output_c(output_value); should do it.

[MCUprogrammer]

output_value |= (value & 0x07); ok I said for this code. so actually, doesn't that mean the following code? How is the expansion done here?
output_value = output_value | (value & 0x07);
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MCUprogrammer
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[PCM programmer]

You want to know if two lines of C code produce the same result.
You can investigate questions like this by yourself.

Make a test program to do this. Example:

[MCUprogrammer]

Ok, I know they both produce the same code. I have explained above. What I want to tell. First, it did the bitwise operation inside the parentheses and produced a single binary code. then how it handles it with output_value. For example;
output_value = output_value | (value & 0x07);
first of the above code (value & 0x07); processed here. (00000101 & 00000111) bitwise result of operation 00000101
later

what is the value of output_value here.
output_value = output_value | 00000101 bitwise operation is done here and what is the output_value
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MCUprogrammer
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[PCM programmer]

What is the initial value of output_value ? We need to know that, before
we can tell what the result is.

[MCUprogrammer]

initial value = 00000000
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MCUprogrammer
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[PCM programmer]

Well it's very simple:

0 | 00000101 gives 00000101 as the result.

This is something you should learn from a book on the C language.

[MCUprogrammer]

thanks sir...
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MCUprogrammer
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