SPRUIW9C October 2021 – March 2024 TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
Single-buffer mode is selected when the MBUF MODE bit is cleared to 0. In this mode, LIN waits for data to be written to TD0, transfers the data to SCITXSHF, and transmits the data. The TXRDY and TX EMPTY bits indicate the status of the transmit buffers. That is, when the transmitter is ready for data to be written to TD0, the TXRDY bit is set. Additionally, if both TD0 and SCITXSHF are empty, then the TX EMPTY bit is also set.
You can transmit data by:
In polling method, software can poll for the TXRDY bit to go high before writing the data to the TD0. The CPU is unnecessarily overloaded by selecting the polling method. To avoid this, you can use the interrupt or DMA method. To use the interrupt method, the SET TX INT bit is set. To use the DMA method, the SET TX DMA bit is set. Either an interrupt or a DMA request is generated the moment the TXRDY bit is set. When the LIN has completed transmission of all pending frames, the SCITXSHF register and the TD0 are empty, the TXRDY bit is set, and an interrupt/DMA request is generated, if enabled. Because all data has been transmitted, the interrupt/DMA request can be halted. This can either be done by disabling the transmit interrupt (CLR TX INT) / DMA request (CLR TX DMA bit) or by disabling the transmitter (clear TXENA bit). If the checksum scheme is enabled by setting the Send Checksum (SC) bit to 1, the checksum byte is sent after the current byte transmission. The SC bit is cleared after the checksum byte has been transmitted.