Progressive Clock Switching for MPC5744P

[jonas_andersson]

We are using the MCP5744P MCU and have had problem with voltage fluctuations when the clocks are initialized. In the reference manual there is a section about Progressive Clock Switching (PCS) and we have used the AN5304 application note in order to implement this feature.

When running the example in AN5304 the core get stuck in an exception (machine_check_int_handler) when trying to start the core (with the line of code attached below) and need help to understand why we end up in this state.

/******************** Start the core **********************/
/* Main and checker cores running in RUN3:0, DRUN, SAFE, TEST modes */
MC_ME.CCTL0.R = 0x00FE;

Notes/Observations

• When reading the value of MC_ME.CCTL0.R I can see that it already has the expected value (0x00FE) before the assignment.  
• The MCU has an external oscillator with 24MHz (40 MHz in example). 

AN5304 application note link:

https://www.nxp.com/docs/en/application-note/AN5304.pdf 

[petervlna]

Hi,

Did you reconfigured clock initialization from  40MHz XOSC to 24MHz?

Peter

[jonas_andersson]

Hi Peter,

The XOSC we have is 16MHz (not 24MHz as I previously wrote) and we have configured PLL0/1 parameter to use PLL0_PHI1 as input to PLL1_PHI.

The output frequency of PLL1_PHI is 200MHz, same as in the example in AN5304 and we have also used the same PCS parameters as in the example (MC_CGM.AC4_SC.B.SELCTL is changed from XOSC to PLL0_PHI1).

[meedandeys]

Hello Jonas, 

Do  you have any resolution for this issue ? I am seeing similar issue. Please provide the resolution if you have.

Thanks