SPRUIN7C March 2020 – March 2024 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
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.