Revision and verification of an enhanced UART

This paper describes the design of an eUART (enhanced universal asynchronous receiver and transmitter) that has been designed as an extension module for the SPEAR processor in order to interact with a TTP/A (time-triggered protocol class A) or LIN (local interconnect network) network. The eUART is able to automatically synchronize its baud rate using a synchronization pattern from the message sender. Furthermore, to enhance the robustness of the communication, the eUART module is equipped with a filter state-machine and provides 16fold oversampling. The interpretation of the samples can be configured in order to optimize towards fault detection or availability. The paper describes the capabilities and limits of this approach and shows the advantages of the eUART when used for real-time communication.