# Bitwise operation help

**URL:** <https://forum.kirupa.com/t/bitwise-operation-help/272109>\
**Category:** Uncategorized\
**Created:** [October 2, 2008, 3:56am UTC](https://forum.kirupa.com/t/bitwise-operation-help/272109 "2008-10-02T03:56:52Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![wo1olf](https://avatars.discourse-cdn.com/v4/letter/w/278dde/32.png) [@wo1olf](https://forum.kirupa.com/u/wo1olf)\
**Post date:** [October 2, 2008, 3:56am UTC](https://forum.kirupa.com/t/bitwise-operation-help/272109/1 "2008-10-02T03:56:52Z")

</div>

given a register, eg MCUCR  
when i have code like this

```auto
MCUCR |= _BV(some number here)

```

doesit only mean a simple “OR” on both, or it does also other thing.  
I am asking because when i compile the code i get a warning sayint that left shif is \>= to width type (for MCUCR).  
thnks