AN 742: PMBus SmartVID Controller Reference Designs

ID 683352
Date 5/08/2017
Public

1.2.1. Multi-Master Mode

When multiple devices start to communicate at the same time, the device writing the most zeros to the bus or the slowest device wins the arbitration. The other devices immediately discontinue any operation on the bus.

When there is an ongoing bus communication, all devices must detect the communication and not interrupt it. The devices must wait for a stop condition to appear before starting communication to the bus.

In this mode, all masters must be multi masters in a multi-master system. Single-master systems may not understand the arbitration and busy detection mechanisms causing unpredictable results.