I ask the customer to send me the register list of their project, then I found some problems:
As we can see, PMC module's LMSTAT = 0, LMEN = 0, and LMAUTOEN = 0.
In the reference manual, we can find that:
LMSTAT indicates the current status of the Last Mile Regulator, if LMEN = 0, the software should make sure that the system clock is on FIRC or slower, to use higher clock speed, the software must set LMEN = 1.
According to the explanation of S32K3's power supply, in BOOT regulation stage, VDD_HV_A is not only the power supply of IO, flash, and some other peripherals, but also the power supply of the core(the voltage is converted to 1.1 by BOOT regulator):
Once the MCU is booted, PMC module supposes to turn the RUN regulator on to let the external 1.5V supply the core:
If the PMC module keeps to work in the BOOT regulation stage, when the system clock is on PLL, the core needs a relatively large current, the heat will be accumulated on the BOOT regulator.
To solve this problem, we should set LMAUTOEN = 1, but in RTD 1.0.0, once you enable LMAUTOEN, it requires you to enable LMBCTLEN:
It makes no sense, because we only enable LMBCTLEN when there is no external 1.5V input(we use a external transistor to convert VDD_HV_A to 1.5V).
After discussion with BL's colleagues, the solution is that we can enable "Mcu Disable Power Management Controller Initialization" in Mcu - General, in this way, LMAUTOEN will be set to 1, as LMAUTOEN = 1 is the default setting.
As we can see, after enabling Mcu Disable Power Management Controller Initialization, LMAUTOEN = 1, LMSTAT = 1, Last Mile Regulator is successfully turned on, MCU works in Full Performance Mode.
In RTD 2.0.0, LMAUTOEN can be set without enabling LMBCTLEN.
I ask the customer to send me the register list of their project, then I found some problems:
As we can see, PMC module's LMSTAT = 0, LMEN = 0, and LMAUTOEN = 0.
In the reference manual, we can find that:
LMSTAT indicates the current status of the Last Mile Regulator, if LMEN = 0, the software should make sure that the system clock is on FIRC or slower, to use higher clock speed, the software must set LMEN = 1.
According to the explanation of S32K3's power supply, in BOOT regulation stage, VDD_HV_A is not only the power supply of IO, flash, and some other peripherals, but also the power supply of the core(the voltage is converted to 1.1 by BOOT regulator):
Once the MCU is booted, PMC module supposes to turn the RUN regulator on to let the external 1.5V supply the core:
If the PMC module keeps to work in the BOOT regulation stage, when the system clock is on PLL, the core needs a relatively large current, the heat will be accumulated on the BOOT regulator.
To solve this problem, we should set LMAUTOEN = 1, but in RTD 1.0.0, once you enable LMAUTOEN, it requires you to enable LMBCTLEN:
It makes no sense, because we only enable LMBCTLEN when there is no external 1.5V input(we use a external transistor to convert VDD_HV_A to 1.5V).
After discussion with BL's colleagues, the solution is that we can enable "Mcu Disable Power Management Controller Initialization" in Mcu - General, in this way, LMAUTOEN will be set to 1, as LMAUTOEN = 1 is the default setting.
As we can see, after enabling Mcu Disable Power Management Controller Initialization, LMAUTOEN = 1, LMSTAT = 1, Last Mile Regulator is successfully turned on, MCU works in Full Performance Mode.
In RTD 2.0.0, LMAUTOEN can be set without enabling LMBCTLEN.
