AnsweredAssumed Answered

PIT Timer Problem

Question asked by jjacp on Nov 30, 2017
Latest reply on Dec 5, 2017 by jjacp

Hi dumitru-daniel.popa,


I’m currently on Lecture 10 (Open Loop with Speed Estimator) in your MPC5744P Model-Based BLDC Motor Control class, but I am stuck. It seems that in my Open Loop model, the PIT only fires 3 to 5 times at startup, and then stops (see attached FreeMASTER screenshot), and so the estimated speed is always zero.


To double check the PIT, I created a new model that only has a PIT on Channel 1, and increments a variable every time it is called. The model and FreeMASTER screenshot is attached. As you can see, the Test_Count variable is never changed, so it seems as though the PIT never fires and the ISR is never invoked.


I checked the generated C source code files, and it looks like the PIT is getting initialized and called correctly. I also checked the intc_sw_vectable.c file (as per this issue, in which the poster’s description of the problem seems very similar), and the PIT ISRs are assigned the proper slots.


Have you encountered this error before??


Here are details on my setup:




BLDC motor with 3 Hall-Effect sensors




NXP Model Based Design Toolbox v2.0.0

S32DS Power v1.2 Compiler

FreeMASTER 2.0

Hotfixes 3 and 5 from


Thank you!!