SJA1105PEL clear dynamically learned MAC addresses + Reset Generation Unit (RGU)

[LUss]

Hi all!

I was wondering how to clear dynamically learned MAC addresses from the switch?

The only way to do it is to reset the switch?

In that case (ref. 6.2 Reset Generation Unit (RGU)) the SWITCH_RST is ok?

Could someone give me other details about the SWITCH_RST? What does it means "Main reset for all functional modules"? All dynamic re-configurations performed during run-time are cleared, dynamically learned addresses from the switch too?

Thanks in advance for your attention,
Luca

[kaden · Accepted solution]

Hi @LUss 

If you have almost always up to 1024 entries when you want to purge all entries, I assume it would be easier to just reset the switchcore and reload the static configuration instead of iterating over every entry and invalidating them one by one. Even checking which entries are valid and then invalidating them wouldn't necessarily be faster since it involves a read first before eventually invalidating the respective entry. 

After SWITCH_RST the static configuration needs to be reloaded.

BR

Kevin 

[kaden]

Hi @LUss 

You can either perform a reset or use dynamic reconfiguration to invalidate entries in the L2 Lookup Table. Please refer to the user manual, chapter "6.1.3 Dynamic reconfiguration" for more information about the respective registers.

 SWITCH_RST does only trigger a reset of the switch logic (which includes all switch configuration tables as well as dynamically learned addresses), but it does not reset CGU (Clock Configuration Unit) and ACU (Auxiliary Configuration Unit). 

BR

Kevin 

[LUss]

Hi Kevin,

Is it better to invalidate all 1024 available entries or is it ok to check which entries are valid and invalidate them?
In the meantime I've decided to set in the static configuration a MAXAGE of the maximum value, and then when I need to clear dynamically learned entries I set MAXAGE to minimum value (1) temporarly and then I restore it to maximum value. I do this after a network topology change to "purge" the entries which will be invalid after this change.

After SWITCH_RST the static configuration doesn't need to be reloaded?

Thanks!
Luca