8540 cpu type corresponds to e500v1 core while
8548 cpu type corresponds to e500v2 core
See https://www.nxp.com/products/processors-and-microcontrollers/legacy-mpu-mcus/powerquicc-processors:POWERQUICC_HOME#powerquicc-iii-mpc85xx
and https://www.nxp.com/docs/en/application-note/AN2807.pdf .