Arm Development Studio forum Cortex A9 WFE instruction not working as expected

This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Cortex A9 WFE instruction not working as expected

Note: This was originally posted on 10th October 2012 at http://forums.arm.com

I'm trying to do a simple test with WFE instruction and EVENTI/O signals. I'm trying to have one A9 enter a wait state with WFE, and have another A9 do some dummy operations while the first is waiting, then do SEV instruction to signal from its SIGNALO to the other A9's SIGNALI. I can verify with my simulation envronment that this signal fires. However, the first A9 is not waiting, it breezes right by the WFE instruction. No assembler warning indicating these instructions aren't supported.

My best clue is in the assembler guide there is the line "If the Event Register is set, WFE clears it and returns immediately," it sounds like this might be happening, but I can't find any reference to "Event Register" in the Cortex A9 TRM, so I'm not sure if this is active by default in my system or what.

Any ideas? Thanks!