SPRUHZ7K August 2015 – April 2024 AM5706 , AM5708 , AM5716 , AM5718 , AM5718-HIREL
In store and controlled transmission (SCT) mode, the MPU starts writing data to the TX FIFO. Then, after writing a part of a frame (for a bigger frame) or an entire frame (a small frame; that is, a supervisory frame), the MPU writes 1 to the UART3.UART_ACREG[2] SCTX_EN bit (deferred TX start) to start transmission.
SCT mode is enabled by setting the UART3.UART_MDR1[5] SCT bit to 1. This transmission method differs from normal mode, in which data transmission starts immediately after data is written to the TX FIFO. SCT mode is useful for sending short frames without TX underrun.