ETPUA channel 0

[mathias_edman]

Hi,

Regarding etpu. As I understand it, for MPC5636 the crank input should be connected to etpu channel 0.

I am now using mpc5777C and I downloaded the example AN4908SW for MPC5746R (closest match) where I see that the cam input is instead used for etpu channel 0.

    /* Setup eTPU A inputs */
    SIUL2.MSCR512_955[512-512].R = 9;  // eTPU A ch0 = PH[11]
    SIUL2.MSCR0_255[123].R = 0x008A0000;  // PH[11] -> PH[11] - Cam
    SIUL2.MSCR512_955[514-512].R = 9;  // eTPU A ch2 = PH[13]
    SIUL2.MSCR0_255[125].R = 0x008A0000;  // PH[13] -> PH[13] - Crank‍‍‍‍‍‍‍‍‍‍

I am a little confused about this. Do you have any recommendation where to put the crank and cam input signal for mpc5777C?

Mathias

[AndreiC · Accepted solution]

The constraint is not an eTPU feature, it is a feature of the engine management microcode.

The CRANK input signal (section 4.1.2 of AN4907) has to be on either channels 0, 1, or 2, but if you decide to use 0 do some reading as to what "input signal connected to TCRCLK" implies but does not state.

On my project, using MPC5634M, I built a simulator with the  cam and crank output generation code (TG) on channels 1 and 3 respectively, and these are jumpered to cam and crank inputs on channels 0 and 2 respectively.

The cam code doesn't care which pin it is associated with, and you can have more than one cam input. The constraint is on the crank signal. Stick to channels 1 or 2.

Non-authoritatively,

Andrei (from The Great White North)

[mathias_edman]

Thanks a lot, much appreciated!