In general, you get the error message "Plugged debug cable is not suitable for CPU", when the started TRACE32 application is not supported by the debug cable plugged to your PowerDebug.
E.g. The "PowerPC-4xx Debug Cable" is not suitable for "TRACE32 for Arm" (t32marm.exe)
Please start the correct TRACE32 application or connect the correct debug cable to your PowerDebug.

As a special case, you also get the error message "Plugged debug cable is not suitable for CPU" if you use a TRACE32 version older than R.2018.02, and you use a new debug cable that is not yet supported by that version:    

• If your Arm debug cable has a serial number starting with "C18" or higher, it is the "ARM Debug Cable V5" (shipped since 2018). Please ensure you use TRACE32 version R.2017.02 or higher.    

• If you use the Automotive PRO cable, ensure you use TRACE32 R.2018.02 or higher.

You can download a suitable version of TRACE32 at https://www.lauterbach.com/7373