US Patent 7423549 Digital control circuit for serial UART transmissions

A digital control circuit enables/disables the feedback of serial transmissions of an UART receive signal when the G-LINK output port is short circuited in a particular operational mode. In a conventional operational mode, the digital control circuit monitors the state of the UART's Tx output and during an UART transmission, the Rx line normally is used for statistics feedback to set to a high state and eliminate unnecessary or unwarranted UART interrupts generated by the G-LINK circuit. The digital control circuit thus enables the G-LINK signal feedback to the UART when required, thereby maintaining a functionality to identify the unit's operational mode and allows the serial ports of the G-LINK to be configured and utilized during conventional operational modes.