I have just designed a new tower plug-in module to help prototype a zigbee design, and I noticed that in the TWRK20D50M_SCH.PDF schematic, connector J3 has pin 11 labeled as 'PTD4_EBI_AD2/DSPI0_PCS1/FTM0_CH4' and SPI0_CS1_B, and it also has pin 20 labelled as 'PTD4_EBI_AD2/DSPI0_PCS1/FTM0_CH4' and UART0_RTS. (Yes the long names are the same!)
I checked my tower board (TWR-K20D50M) and pin11 is connected to pin 20.
This seems to be a mistake.
the pin-out listed in the TWRK20D72 user manual, and in other places, shows the following for the general purpose tower plug-in
(in the TWR schematic J10 and J3 are the TWRPI, instead of J4 and J5 below)