SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
The FSI transmitter can send data that is continuously applied with the DMA. A DMA trigger is generated every time a data frame transmission is completed. This is concurrent with the FRAME_DONE signal that sets the TX_EVT_STS.FRAME_DONE flag.
To transmit continuous data with the DMA, some configurations need to be made on the transmitter:
First, set TX_DMA_CTRL.DMA_EVT_EN to 1. This allows the DMA trigger to propagate to the DMA module. Next, TX_OPER_CTRL_LO.START_MODE must be set to 0x2. The transmitter is now able to start a transmission using a software write to TX_FRAME_CTRL.START or TX_FRAME_TAG_UDATA..
The DMA must also be configured properly for the FSI to send the data. One way of using the DMA to continuously feed the transmit buffer is: