The Predictive p-persistent CSMA algorithm defined in the CEA-709.1 Standard is based on a random number generation.
This random number is automatically generated by an internal algorithm.
In addition, a USART IC DIFF register (US_ICDIFF) is available to avoid that two same chips with the same software generate the same random number after reset. The value of this register is used by the internal algorithm to generate the random number. Therefore, putting a different value here for each chip ensures that the random number generated after a reset at the same time, will not be the same. It is recommended to put the chip ID code here.