Strobe Bits of ATmega

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Milo-D
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Posted by Milo-D: Thu. Oct 15, 2020 - 10:37 PM
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Hey.

 

So I've just read about the FOC0/FOC2 bit, which is implemented as a strobe and triggers an immediate compare match when writing a logical one to it.

So what exactly is a strobe in this context ? What is so special about strobe bits ? Is it maybe the fact that even when writing a logical one to FOC, its value will be always read as zero ? 

 

The earliest use of the 'strobe' keyword is at page 20 of the ATmega32 datasheet, but sadly without any further explanation.

I need these details for my simulator and sometimes datasheet is not enough :)

 

Thank you.

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AVR Microcontrollers, megaAVR and tinyAVR, solved
Last Edited: Fri. Oct 16, 2020 - 02:14 AM
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Kartman
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This reply has been marked as the solution. 
Posted by Kartman: Fri. Oct 16, 2020 - 01:33 AM
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The act of writing a ‘1’ is a one-shot. You’re not writing a bit as such but causing an action.

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Milo-D
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Posted by Milo-D: Fri. Oct 16, 2020 - 02:17 AM (Reply to #2)
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Thank you Kartman :)

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Scroungre
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Posted by Scroungre: Fri. Oct 16, 2020 - 03:50 AM
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Or, putting it another way, it's a bit that when you write '1' to it, on the very next cycle it writes itself back to '0', thus saving you (programmer and CPU) the hassle of clearing it manually.  When '1' it causes an action, but doesn't stay at '1' once the action has been triggered.

 

Some strobes (although none, as far as I know, in the AVR) work the other way, sitting at '1' until flipped to '0' - and flipping right back.  S.

 

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awneil
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Posted by awneil: Fri. Oct 16, 2020 - 08:02 AM
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Kartman wrote:
You’re not writing a bit as such but causing an action

This is an important thing to understand about SFRs - see: https://www.avrfreaks.net/commen...

 

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