MPC5745R : unavailable ports and their impact on eTPU processing

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MPC5745R : unavailable ports and their impact on eTPU processing

Contributor III

Hi, I use the eTPU2 on MPC5745R to generate PWMs for motor control.

A recommended design strategy for eTPUs is to assign the base and complementary pwm outputs to adjacent channels in order to leverage the registers for parameter passing between the two. 

I assigned the phase W pwm channels as below:

PhaseW_Base                     eTPU9_A       PG[2]

                                                                   //PG[3], PG[4] not available on LQFP

PhaseW_Complementary    eTPU11_A     PG[5]

Note that physically they are not adjacent channels. However, on the LQFP package, eTPU10_A  configurable port, PortPG[4] is not available. It is too late in the design to search for another set of 3 adjacent eTPU chans. So my questions are:

(a) if the port is unavailable on the package, will the eTPU still schedule the chan processing? I would think so, for the eTPU scheduler has no knowledge of package. Need confirmation.

(b) Is it possible to prevent scheduling eTPU10_A ? Or in other words, can I force the eTPU to transition from chan9_A to chan11_A, in which case the two will effectively be "adjacent" and I can leverage the registers for parameter passing.

Thank you for your suggestions.


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NXP TechSupport
NXP TechSupport


a) Yes, eTPU has no knowledge of the package.

b) You would have to modify eTPU source code to allow something like that. I have checked eTPU source code (both PWMMAC/PWMMDC and PWMM from new implementation), both uses for complementary channel just increasing by 1.