Query about Bitwise operations

[alsaf]

I had come heard of Bitwise but I didn't really understood it until recently when I had being learning Assembly language programming. While I understood its principles and how it worked, I didn't really know what purpose it was for. From research the some purposes are bit fields/flags and arithmetic.

I would assume, in terms of embedded programming, using bitwise operations for arithmetic purposes would be better than built-in ones when doing heavy number crunching operations but would it be beneficial or even noticeable if any occasional calculations were required?

 

[Harald Kapp]

Hi alsaf,
bitwise operations are not for arithmetic purposes, although one could use them in that way.

There are several uses for bitwise operations. Just afe to mention:
1) store lot of data with little memory. E.g. ona an 8 Bit computer, an 8 bit data word could be used to store the presence or absence of 8 different properties. Bit n=1 could mean property "n" is present, Bit n=0 could mean property "n" is missing. To set, clear and check single bits, you need bitwise operations. In this example you need only 1 data word instead of 8 words to store this infiormation.
2) set, clear and check single port bits of a microcontroller. A microcontrollers I/Os are very often grouped in words of 8, 16 or 32 bits. You need bitwise operations e.g. to set a singel I/O line to high or low or to check its status.

You will find more usefull information especially on bitwise operations in maicrocontroller manuals.

Regards,

Harald

 

[alsaf]

Thanks for the info Harald, much appreciated.