During the course of automatic baud detection, the ABDOVF bit of the BAUDCON register will be set by Extract PIC10F320 Flash/Eeprom Memory Code if the baud rate counter overflows before the fifth rising edge is detected on the RX pin.
The ABDOVF bit indicates that the counter has exceeded the maximum count that can fit in the 16 bits of the SPBRGH:SPBRGL register pair when Extract IC Through Backside. After the ABDOVF has been set, the counter continues to count until the fifth rising edge is detected on the RX pin.
Upon detecting the fifth RX edge, the hard- ware will set the RCIF interrupt flag and clear the ABDEN bit of the BAUDCON register. The RCIF flag can be subsequently cleared by reading the RCREG register by Extract Microcontroller Code. The ABDOVF flag of the BAUDCON register can be cleared by software directly.
Extract PIC10F320 Flash Eeprom Memory CodeTo terminate the auto-baud process before the RCIF flag is set, clear the ABDEN bit then clear the ABDOVF bit of the BAUDCON register. The ABDOVF bit will remain set if the ABDEN bit is not cleared first.
During Sleep mode, all clocks to the EUSART are suspended. Because of this, the Baud Rate Generator is inactive and a proper character reception cannot be performed from Extract PIC10F320 Flash/Eeprom Memory Code. The Auto-Wake-up feature allows the controller to wake-up due to activity on the RX/DT line. This feature is available only in Asynchronous mode.
The Auto-Wake-up feature is enabled by setting the WUE bit of the BAUDCON register. Once set, the normal receive sequence on RX/DT is disabled, and the EUSART remains in an Idle state, monitoring for a wake-up event independent of the CPU mode. A wake-up event consists of a high-to-low transition on the RX/DT line. (This coincides with the start of a Sync Break or a wake-up signal character for the LIN protocol.)
