In ConfigTool, TEE section in misc have configuration for SCnSCB->CPPWR register.
But it is not explained in UM/DS and in generic ARM docs mentioned that it have some effect for co-processor powering.
Do you have info how to configure this register properly for LPC55 ?
I agree with that there is not any documentation which addresses the register and gives bit definition.
I will ask AE team for the bit definition of the SCnSCB->CPPWR register.