AIRCR.PRIS = 1 / PRIMASK_NS=1 Higher priority secure interrupts are disabled

[alessandro morniroli]

Hi,

I'm playing with Nucleo-u575zi and GPIO_IOToggle_TrustZone example.

Everything is working as expected.

I want to be sure that systick of secure zone is never blocked by nonsecure zone (e.g. setting PRIMASK_NS =1). In secure mode, at startup, I then set AIRCR.PRIS=1 (SYSTICK_S priority is set to '1').

I would expect that setting PRIMASK_NS to one boosts the current execution priority to 0x80, but it's also masking SYSTICK_S irq (it stops to be triggered, so non secure world is "killing" secure world).

Am I missing something?

[alessandro morniroli · Accepted solution]

Nevermind, it's working as expected, my bad.