SWRU543B January 2019 – June 2025 CC3230S , CC3230SF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
The slave module also has the capability to use the µDMA in RX and TX FIFO data transfers. If the TX FIFO is assigned to the slave module and the TXFIFO bit is set in the I2CSCSR register, the slave module generates a single µDMA request, dma_sreq, if the master module requests the next byte transfer. If the FIFO fill level is less than the trigger level, a µDMA multiple transfer request, dma_req, is asserted to continue data transfers from the µDMA.
If the RX FIFO is assigned to the slave module and the RXFIFO bit is set in the I2CSCSR register, then the slave module generates a signal µDMA request, dma_sreq, if there is any data to be transferred. The dma_req signal is asserted when the RX FIFO has more data than the trigger level programmed by the RXTRIG bit in the I2CFIFOCTL register.
TI recommends that an application should not switch between the I2CSDR register and TX FIFO or vice versa for successive transactions.