Enable/Disable Interrupts globally

kostyak · ‎2008-02-15

Posted on February 15, 2008 at 22:20

kostyak · ‎2011-05-17

Posted on May 17, 2011 at 12:23

Hi !

How can I easily enable / disable all interrupts with one instruction ?

regards

Manfred

joseph239955 · ‎2011-05-17

Posted on May 17, 2011 at 12:23

Not exactly one instruction, but you can disable all interrupts in one go by setting the PRIMASK special register. To do this, you need to use MSR instruction (in assembly):

MOVS R0, #1

MSR PRIMASK, R0 ; Set PRIMASK to 1

Depends on the development tool and library you are using, there might be some device drive function that can do this for you.

ericvanolden9 · ‎2011-05-17

Posted on May 17, 2011 at 12:23

You CAN with only one instruction.

CPSIE I write 0 in PRIMASK so interrupts are enable

CPSID I write 1 in PRIMASK so interrupts are disable

See ARM DDI 0405A-01, page B3-3

With IAR compiler, you have intrinsic function __disable_interrupt() and __enable_interrupt() which put inline these instructions. With GNU compiler you can easily use __asm() directive to put these instructions in your code.

joseph239955 · ‎2011-05-17

Posted on May 17, 2011 at 12:23

Oops, yes of course.

I completely forgot about these two instructions.

Thanks for reminding me 🙂