Microcontroller-MPC5675K-Reset issue

[ArunaNellaiappan]

Dear Team,

Warm Greetings.

We are using SPC5675KFF0VMS2-Micro Controller for our application. We face the reset issue in the controller. Every power ON, we read the status of the Functional (RGM_FES)as well as Destructive event status register(RGM_DES). (Refer 46.3.1.1 in MPC5675KRM reference manual for register details)

It was updated as,

Functional event status register : 0x9000

Destructive event status register: 0x8000

Even though we are resetting the controller externally after power on , the RGM_DES status remains 0x8000.

We followed following sequence,

1) Read the RGM_FES & RGM_DES register after power ON

2) Clearing the status register and read back the same.(RGM_FES: 0x0; RGM_DES: 0x0)

3) After the external reset ( toggling the reset pin externally) released , the RGM_DES register should be 0x0(since POR is not happened). But it was updated as 0x8000.

Please provide suggestion to proceed further.

[ArunaNellaiappan]

The following sequence followed,

we cleared the power on reset bit manually by writing the 0xC3FE4002 as 1( suspecting clear is not done properly).

After the external reset (pin AC20) was released, the RGM_DES register remains 8000. ( Indicating power on reset happened). The queries are,

1) what will be the expected range of VDD_HV_xxx , VDD_LV_xxx ( during external & internal vreg mode)?

2)  how to check the  2.7V generated inside after the reset occured?

3) what will be the DRAM supply voltage ?

Also, Provide suggestion to proceed further

[petervlna]

Hello,

From your description the only possible cause is that once you trigger external reset, your also loose power to micro somehow.

Please do the same with voltage monitoring via scope, to see if the power is always within datasheet specification.

On top of that you can do tests on NXP Evaluation board to exclude any HW issue.

Best regards,

Peter

[ArunaNellaiappan]

This is a gentle reminder.

Please Provide suggestion to proceed further

The following sequence followed,

we cleared the power on reset bit manually by writing the 0xC3FE4002 as 1( suspecting clear is not done properly).

After the external reset (pin AC20) was released, the RGM_DES register remains 8000. ( Indicating power on reset happened). The queries are,

1) what will be the expected range of VDD_HV_xxx , VDD_LV_xxx ( during external & internal vreg mode)?

2)  how to check the  2.7V generated inside after the reset occured?

3) what will be the DRAM supply voltage ?

[ArunaNellaiappan · Accepted solution]

Hi,

Sorry for the delayed response.

As per your suggestion, We have probed the External reset as well as Microcontroller Supply line.(image attached). Though we gave the external reset,the Micro Controller didn't loose its power.

Provide suggestion to proceed further.