When the power supply voltage of the MPC5742P gradually decreases from 3.3V to around 3.1V, the MPC5742P will continuously reset itself (detect the reset pin through the oscilloscope); When the power supply voltage of the MPC5742P is raised to the normal supply voltage of 3.3V，the C55FMC.MCR register (address 0xFFFE0000) is modified when the clock initialization MC_MODE_INIT function is executed. For details, see the attached picture (execution MC_ME.MCTL.R=0x3000A50; after) .
Abnormal modification of the C55FMC.MCR register will cause the DFLASH (C55 Flash) function to execute abnormally, which may cause the system to fail.
Hi,
When the power supply voltage of the MPC5742P gradually decreases from 3.3V to around 3.1V, the MPC5742P will continuously reset itself (detect the reset pin through the oscilloscope)
Yes, this is correct. See datasheet specifications:
When the power supply voltage of the MPC5742P is raised to the normal supply voltage of 3.3V，the C55FMC.MCR register (address 0xFFFE0000) is modified when the clock initialization MC_MODE_INIT function is executed. For details, see the attached picture (execution MC_ME.MCTL.R=0x3000A50; after) .
You mean after reset is executed by PMC (power management controller). What exactly is doing your code when you check assembly instructions step by step? Is it writing to MCR register? (I expect this is the only way to change MCR)
How about optimizations? I cannot judge from the C code screenshot much.
Debug the code assembly. I expect the issue in used code. Is this same if you use our example reference codes?
regards,
Peter
