AnsweredAssumed Answered

FlexCAN refuses to leave Low Power Mode

Question asked by Nick Borton on Dec 15, 2016
Latest reply on Dec 21, 2016 by Kan_Li

I have an application where I change clock sources and modes frequently, and the FlexCAN clock source, and baud rates also change to match.


Currently I have FlexCAN enabled in the FBE and PEE modes.


When in FBE, FlexCAN is sourced from the bus clock, which is directly driven by the RTC crystal output and running at a baud of 1.5k.


When in PEE, FlexCAN is sourced from the OSC, which is driven at 10MHz, and CAN is running at a baud of 1M.


In all other MCG modes, the FlexCAN module is either held in freeze or the module is disabled.


I am currently running into a situation where during one of these clock changes, the FlexCAN never comes out of module disable (or low power) mode.


The sequence is as follows:


PEE mode, FlexCAN operating.

FlexCAN enter freeze

Switch to FEE mode.

FlexCAN disabled.

Switch to FBE mode.

FlexCAN clock source changed, and module enabled <------ here the LPMACK bit never goes low


I am using the MK60FN1M0VMD12.