Reset the micro (MPC5643 ) using while(1) loop

[bnaiduv]

When I am trying to reset the micro (MPC5643 ) using while(1) loop It is resetting for some time and after that Reset line becomes low and not going high. Is it a safety Implementation in the micro?

[davidtosenovjan]

That's interesting. As I know such feature exists on MPC5744P and other MPC57xx devices - it is called 'Functional' Reset Escalation and 'Destructive' Reset Escalation (MC_RGM_FRET and MC_RGM_DRET) and it causes that after predefined number of functional reset, destructive reset happen and after predefined number of destructive resets, device will stay in reset.

However this feature is not present with MPC5643L so I would expect continuous resetting in case all of these reset has the same reason (SW initiated functional reset).

[liujinhang]

this is a very good problem, and i am now facing it. i did many test and got some interesting result.   in these results only one point i have some doubt and want to know the reason.

1. in 5744P chip the MC_RGM_FRET can do predefine the times allow funciton reset to cause a destructive reset;

2. but the MC_RGM_DRET can not predefine the times allow destructive reset to cause chip freezed in reset status. 

my test is that :

1. write MC_RGM_DRET to be 0 at the initial stage , and then software reset 5744P;   if  the  MC_RGM_FRET is set to be 15, i can see the the chip will be reset 14 times and then stoped.

2. write MC_RGM_DRET to be 15 at the initial stage , and then software reset 5744P; if  the  MC_RGM_FRET is set to be 15, i can see the the chip will be reset 14 times and then stoped.

according to the UM of 5744P specifying, if user write 0 to MC_RGM_DRET , the Destructive' Reset Escalation function will be disabled. but actually not. that is my doubt. what is the reason?