SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Depending on targeted application the MCSPI interface can be configured to use 3 or 4 pins through the MCSPI_MODULCTRL[1] PIN34 bit. If this bit is set to 0, MCSPI is in 4-pin mode using the SPICLK, SPIDAT[0], SPIDAT[1] and SPIEN[i] signals. If PIN34 is set to 1 the controller is in 3-pin mode and SPIEN[i] is not used. In this mode all options related to chip select management are useless (EPOL, FORCE and TCS0 bits of MCSPI_CHCONF_0/1/2/3). 3-pin and 4-pin operation applies to both controller and peripheral modes.