How to know about multiplexed inputs/outputs
Look at Table 2 in the datasheet.

Some of the pins have several signal names : these ones are multiplexed.

For example this pin is not multiplexed:

A4 DDR_WEn ddr_wen 


and this one is

E18 ECAP0_IN_PWM0_OUT eCAP0_in_PWM0_out 
                      uart3_txd 
                      spi1_cs1 
                      pr1_ecap0_ecap_capin_apwm_o 
                      spi1_sclk 
                      mmc0_sdwp 
                      xdma_event_intr2
                      gpio0_7