SPRUI33H November 2015 – June 2024 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
Before the SCI sends or receives data, the SCI registers can be properly configured. Upon power-up or a system-level reset, each bit in the SCI registers is set to a default state. The registers are writable only after the RESET bit in the SCIGCR0 register is set to 1. Of particular importance is the SWnRST bit in the SCIGCR1 register. The SWnRST is an active-low bit initialized to 0 and keeps the SCI in a reset state until the bit is programmed to 1. Therefore, all SCI configuration can be completed before a 1 is written to the SWnRST bit.
The following list details the configuration steps that software can perform prior to the transmission or reception of data. As long as the SWnRST bit is cleared to 0 the entire time that the SCI is being configured, the order in which the registers are programmed is not important.