Is it possible to put the Sitara (AM335x) USB on the FIQ?
Further, is there a problem with enabling/disabling the FIQ on the Cortex A8 in the Sitara? It seems I am able to disable the IRQ using
mrs r0, CPSRorr r0, #0x80msr CPSR_c, r0
But disabling the FIQ using
MRS r0, CPSRORR r0, #0x40MSR CPSR_c, r0
Seems to fail. It is like the FIQ bit in the Cortex A8 is stuck on. And yes I am in a Privileged (System) mode when I try this.
FIQ is not supported in AM335x. You can configure the priority of IRQ interrupts.
That confuses me. It is discussed quite a bit in TRM spruh73f.pdf
Is it possible you just meant starterWare or perhaps USB not working with FIQ --- or did you mean the entire AM335x?
It is not the limitation of StarterWare but AM335x. FIQ is not available in AM335x as it is assigned for Security (which is not supported in AM335x). I will work with the corresponding internal team to update the TRM.
This is was a real setback. When is the TRM scheduled to be updated?
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