SPRUI78D March 2019 – January 2022 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S
For McBSP transmission, CPU or DMA controller writes data to the Data Transmit Register (DXR). When new data arrives in DXR, McBSP copies the content of the DXR to the Transmit Shift Register (XSR). On reception of transmit frame-synchronization pulse, McBSP shifts data bits from the XSR to the transmit pin. If new data is not loaded into the DXR before a new frame-synchronization signal arrives, the previous data in the DXR is sent again. The XEMPTY = 0 flag indicates this error condition. This continues for every new frame-synchronization pulse that arrives until the DXR is loaded with new data. XEMPTY = 0 flag condition does not generate an interrupt and CPU has to periodically poll the signal to test the occurrence of error.