http://www.futureelectronics.com/en/campaign/cypress/Pages/index.aspx . This lesson explains the CC (Configuration Channel) including power contract negotiation, Dual Role Prots (DRPs), and role swaps. It shows how the CY4500 EZ-PD Protocol Analyzer can be used along with the EZ-PD Analyzer Utility to understand and debug USB-PD messages. https://youtu.be/TCovpPlNdQ8