SPRUIY4B February 2023 – May 2024 TMS320F2800152-Q1 , TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1
Single-buffer mode is selected when the MBUF MODE bit in SCIGCR1 is cleared to 0. In this mode, SCI waits for data to be written to SCITD, 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 SCITD, the TXRDY bit is set. Additionally, if both SCITD 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 SCITD register. The CPU is unnecessarily overloaded by selecting the polling method. To avoid this, you can use the interrupt method. To use the interrupt method, the SET TX INT bit is set. An interrupt is generated the moment the TXRDY bit is set. When the SCI has completed transmission of all pending frames, the SCITXSHF register and SCITD are empty, the TXRDY bit is set, and an interrupt request is generated, if enabled. Because all data has been transmitted, the interrupt request must be halted. This can either be done by disabling the transmit interrupt (CLR TX INT) or by disabling the transmitter (clear TXENA bit).
The TXRDY flag cannot be cleared by reading the corresponding interrupt offset in the SCIINTVECT0 or SCIINTVECT1 register.