For the PSoC 6 opamp the output can be directly connected to a pin and/or routed to an internal load using the analog routing fabric. The drive strength is selectable as either 10x or 1x. Connections to GPIO pins require the 10x setting. OA0s 10x output is directly connected to pin2. That is the pin recommended to be used when routing the OA0 to an output pin. In case you need the connect the output to some other pins, you can use the AMUX bus for the purpose with expected shortcomings due routing and switch resistances.
Thank you for replay,
I really use AMUX bus for connecting the output to multiple pins, but there is a voltage drop on the op-amp output.
when I connect the op-amp output to the AMUX bus there is no voltage drop, but when i connect the other pins to the bus the voltage drops immediately.
As I said and if you see the routing diagram again pin2 is supposed to be used as the output of opamp. The 10x driver output is directly routed to this pin. Trying to use other pins using the mux will have the disadvantages for the voltage drop. But if you use the opamp buffer before muxing , the output should be better compared to directly routing the output out of the DAC. Pin2 will always have to be used in this case as you are tapping the same output to other pin.