[J-core] Is there a way to have periodic interrupts on the Numato board?

[D. Jeff Dionne]

On Oct 11, 2019, at 18:35, Joh-Tob Schäg <johtobsch at gmail.com> wrote:
> 
> Hello,
> 
> I am curious whether periodic interrupts are possible with the "lastest" (and very old) release of the Numato image?

yes, there is a PIT built in.  Linux uses it.

> If not how could i implement one?
> I also fail to grasp the meaning of count when count_enabled.

the implementation is basic, it’s designed to provide Linux what it needs...
> 
> I already found out that interrupts are queued if the processor has a higher priority than the interrupt and the interrupt is triggered if the level is decreased enough.

J2 implements prioritised exception processing.  The interrupt level in stored in SR, and basically managed by the processor logic itself.  The operation follows the SH2 specification, but not any specific interrupt controller.

The lack of lack of a standard J-Core interrupt controller is a bit of a problem... we’ll make sure it’s a priority to at least document the versions that are in use...

J

> 
> 
> Thanks,
> Johann-Tobias
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