SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
There are five serial port events that can constitute a system error:
This error occurs when DRR1 has not been read since the last RBR-to-DRR copy. Consequently, the receiver does not copy a new word from the RBRs to the DRRs and the RSRs are now full with another new word shifted in from DR. Therefore, RFULL = 1 indicates an error condition wherein any new data that can arrive at this time on DR replaces the contents of the RSRs, and the previous word is lost. The RSRs continue to be overwritten as long as new data arrives on DR and DRR1 is not read. For more details about overrun in the receiver, see Section 20.5.2.
This error occurs during reception when RFIG = 0 and an unexpected frame-synchronization pulse occurs. An unexpected frame-synchronization pulse is one that begins the next frame transfer before all the bits of the current frame have been received. Such a pulse causes data reception to abort and restart. If new data has been copied into the RBRs from the RSRs since the last RBR-to-DRR copy, this new data in the RBRs is lost. This is because no RBR-to-DRR copy occurs; the reception has been restarted. For more details about receive frame-synchronization errors, see Section 20.5.3.
This error occurs when the CPU or DMA controller overwrites data in the DXRs before the data is copied to the XSRs. The overwritten data never reaches the DX pin. For more details about overwrite in the transmitter, see Section 20.5.4.
If a new frame-synchronization signal arrives before new data is loaded into DXR1, the previous data in the DXRs is sent again. This procedure continues for every new frame-synchronization pulse that arrives until DXR1 is loaded with new data. For more details about underflow in the transmitter, see Section 20.5.5.
This error occurs during transmission when XFIG = 0 and an unexpected frame-synchronization pulse occurs. An unexpected frame-synchronization pulse is one that begins the next frame transfer before all the bits of the current frame have been transferred. Such a pulse causes the current data transmission to abort and restart. If new data has been written to the DXRs since the last DXR-to-XSR copy, the current value in the XSRs is lost. For more details about transmit frame-synchronization errors, see Section 20.5.6.