Problem about code relization

[Mizan.Bangladesh]

Hi All, Please look below & help me.


Firstly,

if(temp^0b00000001)

In the above what is the work of '^' operator & how it's work?Please explain.

secondly,
derivative_term = derivative_term >> 5; // divide by 32 precalculated Kp*X*3*Ts.
In the above what is the work of '>>' operator & how it's work? Please explain.


Thirdly,
CCPR1L = Cn >> 2; // Used to stop the pendulum from continually going around in a circle
In the above what is the work of '>>' operator & how it's work? Please explain.


Thanks in advance.

 

[erikl]

Firstly,

if(temp^0b00000001)

In the above what is the work of '^' operator & how it's work?

It's the logical AND operator, see here.

secondly,
derivative_term = derivative_term >> 5; // divide by 32 precalculated Kp*X*3*Ts.
In the above what is the work of '>>' operator & how it's work?

The logical shift right operator, >> 5 results in a divide by 2⁵ = 32 operation.

Thirdly,
CCPR1L = Cn >> 2; // Used to stop the pendulum from continually going around in a circle
In the above what is the work of '>>' operator & how it's work?

Again, shift right (by 2), results in a divide by 2² = 4 operation.

 

[Mizan.Bangladesh]

I give full code below,



temp_int = abs(Cn); // Returns the absolute int value of Cn
temp = temp_int; // int to char of LS-Byte
if(temp^0b00000001){
DC1B0 = 1;
}


please give me example... to realize the meaning of "temp^0b00000001"

Thanks

 

[erikl]

please give me example... to realize the meaning of "temp^0b00000001"

simply a logical AND :

0bxxxxxxx1 ^ 0b00000001 = 0b00000001
0bxxxxxxx0 ^ 0b00000001 = 0b00000000

 

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simply a logical AND :

0bxxxxxxx1 ^ 0b00000001 = 0b00000001
0bxxxxxxx0 ^ 0b00000001 = 0b00000000

^ is the XOR operation logical AND is &.

https://www.asic-world.com/verilog/operators1.html

- - - Updated - - -

I give full code below,



temp_int = abs(Cn); // Returns the absolute int value of Cn
temp = temp_int; // int to char of LS-Byte
if(temp^0b00000001){
DC1B0 = 1;
}


please give me example... to realize the meaning of "temp^0b00000001"

Thanks

I just noticed the { } braces...I guess this is C not Verilog...

^ in C is still bit-wise XOR and & is bit-wise AND.

 

[erikl]

^ is the XOR operation logical AND is &.

https://www.asic-world.com/verilog/operators1.html

- - - Updated - - -



I just noticed the { } braces...I guess this is C not Verilog...

^ in C is still bit-wise XOR and & is bit-wise AND.

You're right with Verilog and C, but it seems to be different for other languages: see the Wiki link given above.

Perhaps the OP Mizan.Bangladesh should tell us which program resp. language he is using.

 

[Mizan.Bangladesh]

Hi thanks to all,

i am using C programing language.

Now, please give me example... to realize the meaning of "temp^0b00000001"

 

[erikl]

Hi thanks to all,

i am using C programing language.

Now, please give me example... to realize the meaning of "temp^0b00000001"

Mizan: If you're writing programs in C language, you really should be able to find the result of the XOR operation yourself!
(The result is exactly the inverse of the AND operation shown above.)

 

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You're right with Verilog and C, but it seems to be different for other languages:

The carret ^ isn't the same as the /\ (think of it as joined at the top ;-)) symbol which is the mathematical(?) AND symbol. I've never seen in any computer sw/hw language the use of ^ for AND, but then again I don't know all of them.

0bxxxxxxx1 ^ 0b00000001 = 0b00000001
0bxxxxxxx0 ^ 0b00000001 = 0b00000000

I don't think this would be valid in C. There is no X in C

The OP should understand the truth table of XOR:
0 0 | 0
0 1 | 1
1 0 | 1
1 1 | 0

This table is applied bit-wise for each pair of inputs, therefore:
temp^0b00000001, if temp is say 0b11110000


1 0 = 1
1 0 = 1
1 0 = 1
1 0 = 1
0 0 = 0
0 0 = 0
0 0 = 0
0 1 = 1

so your answer would be 0b1111001