The processor is usually already verified on its own before it is put into a SoC. Using the raspberry pi example from another thread: broadcom designed the BCM

The processor is usually already verified on its own before it is put into a SoC. Using the raspberry pi example from another thread: broadcom designed the BCM2835 SoC, which included an ARM1176 core. Broadcom probably didn't do a ton of verification for the ARM1176 core itself, since ARM already verified it.