Yes, this is possible, by modifying bits 5 and 4 of the PAMUX_S4 register. The following is the definition of the bits.
Bits 5 to 4: PAMUX_S4:
‘00’ CSA_OUT0 input is multiplexed to AINX.
‘01’ CSA_OUT1 input is multiplexed to AINX.
‘10’ CSA_OUT2 input is multiplexed to AINX.
‘11’ CSA_OUT3 input is multiplexed to AINX.
For more info on this register, refer the PowerPSoC Technical Reference Manual.
The default value of this register results in CSA0 being multiplexed to the AINX. If the intent is to scan only one CSA input and not monitor more than one dynamically, then the input to the AINX Mux can be setup in the Global Resources Tab in the Chip Editor View of PSoC Designer.