MPC5674F: Coding of LVD33TRIM and LVDCTRIM

[matthiasgeipel]

Seems there is a coding error in the description of the LVD33TRIM and LVDCTRIM settings in reference manual table 4-5. For the other fields of PMC_TRIMR, 1111b is followed by 1110b and 1101b, but for LVD33TRIM and LVDCTRIM 1111b is followed by 1101b and then 1110b. Can anyone tell me whether I should trust the reference manual for the description of the mentioned fields? Thanks!

[davidtosenovjan · Accepted solution]

Certainly there is an error in the description. For all field is basically 4-bit signed fixed point integer value, its coding you may see in example below:

Trimmed VDDx  = VDDx + xTRIM * STEPx

I will report your observations as documentation error. Thanks for the info.

[matthiasgeipel]

Thanks for your answer.

So did I understand right, that the coding is wrong in both MPC5674F and MPC5676 reference manual? 1111 should be followed by 1110, 1101 and 1100.

According to the MPC5676RRM, LVDCTRIM is 0000 BEFORE reset. What does "before" mean? Is this the time, before the reset input is deasserted?

1010 is the "Default value at reset". What does that mean? Is this the instant when the internal reset sequence of the µC is finished and RSTOUT is released? But how can you then read  LVCDTRIM=0000 with the debugger instead of 0101?