SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
To send out a block-start signal of exactly one frame time during a sequence of block transmissions:
Because TXWAKE was set to a 1, the start, data, and parity bits are replaced by an idle period of 11 bits transmitted following the last stop bit of the previous frame.
A don’t-care data word must first be written to register SCITXBUF so that the TXWAKE bit value can be shifted to WUT. After the don’t-care data word is shifted to the TXSHF register, the SCITXBUF (and TXWAKE, if necessary) can be written to again because TXSHF and WUT are both double-buffered.