Kari Sipinen

Recommended MQX interrupt levels

Discussion created by Kari Sipinen on Jun 14, 2012



I'm working on custom K53 board using MQX 3.8, MFS, RTCS, USB Device, LPM active, I2C and SPI.


Since I'm working on battery powered device I need to save power and hence do clock switching (internal vs external) and turning things on and off all the time. My setup seems to be working relatively well. But...


Looks like after while Timer task is stuck and LW Semaphore TIMER_ISR_LWSEM keeps counting but timer task is stuck.

Have been browsing this forum and found posts "possible scheduler bug in MQX 3.7" and "Ready task not entered" helpful. https://community.freescale.com/thread/99232


I'm using pretty much "inherited" interrupt levels from twrk53n512.h. For example I2C interrupt levels are 1 which is same that one set for the timer ISR. So, assuming that interrupt priority levels are the source of the problem.

Just wondering what would be recommended Interrupt priorities for the MQX?

Timer 1, I2C and ports 3 other ones 4-5? Something else?