This tutorial explains how to use the 8-bit timer on the ATMega328PB to drive a servo. The 328PB 8-bit timer has 2 control registers. OCR0A can be used to adjust the frequency while OCR0B is used to adjust the pulse width.
4 attachments, a description and 3 programs. The 8bit.PDF is reposted in #4 below. Fixed the Formulas.