IRQ FIQ USB

brad badke

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, CPSR
orr     r0, #0x80
msr     CPSR_c, r0

But disabling the FIQ using

MRS     r0, CPSR
ORR     r0, #0x40
MSR     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.

over 13 years ago

0 Baskaran Chidambaram over 13 years ago

TI__Genius 17370 points

Brad,

FIQ is not supported in AM335x. You can configure the priority of IRQ interrupts.

Regards

Baskaran

0 brad badke over 13 years ago in reply to Baskaran Chidambaram

Intellectual 760 points

That confuses me. It is discussed quite a bit in TRM spruh73f.pdf

0 brad badke over 13 years ago in reply to brad badke

Intellectual 760 points

Is it possible you just meant starterWare or perhaps USB not working with FIQ --- or did you mean the entire AM335x?

0 Baskaran Chidambaram over 13 years ago in reply to brad badke

TI__Genius 17370 points

Brad,

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.

Regards

Baskaran

0 Martin Dahlberg over 13 years ago in reply to Baskaran Chidambaram

Prodigy 10 points

Baskaran,

This is was a real setback. When is the TRM scheduled to be updated?

Regards,

Martin

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IRQ FIQ USB