Honored ContributorDoes any one know if it is possible to setup a Nios II, with internal interrupt controller using shadow register sets? And how does you specify what register set to use for each interrupt?
Honored ContributorEven if it was possible why not use the vectored interrupt controller that already does this?
Honored ContributorAgree, - but just right now it would be a simple solution for me.
Honored ContributorIn that case what are you looking to achieve? Maybe a different method would work for you using the internal interrupt controller (maybe a custom jump table for example).
Honored ContributorI just wanted to get a fast interrupt respons with the internal interrupt controller, - without saving all registers. But as far as I can see, I only got the wrprs and rdprs instructions, - but no instructions to actually switch to a shahow register set during the interrupt processing. - Later in our process we are adding the external interrupt controler, and then my problems will be solved.
Honored ContributorCan't you just write to the CRS field of the status register?
Honored ContributorAs I see it status.CRS is read only.
Honored ContributorI'm sure I'd just checked the docs :-)
In that case you need to execute an 'iret' having set the approriate saved status to the required value. Actualy it is an 'eret', see page 3-28Honored Contributoroh, - I see you point, - but it might as well open for interrupt again. Or maybe I can control this in the saved status? Anyway the code would not be easy to understand and need good comments.
Honored ContributorAn interrupt entry/exit pair should leave the system in the original state - regardless as to the actual current register set. So you should only need to save enough state to restore the original set.
