SPRAD21E May 2023 – February 2024 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP , AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1 , AM62P , AM62P-Q1
The series resistor on the clock output is required to resolve issues with signal distortion at the source of the clock signal because the clock output is also used for retiming. For MMCx interface an unbonded pad is used in the AM62x, AM62Ax and AM62Px processor family, so the series resistor is not a requirement for loopback. In some cases a low value series resistor may be needed for EMI / EMC purpose (reduce radiated emissions). It is recommended to keep the series resistor as a place holder just in case it is needed for improving signal integrity.