Setting output delay

Hello,

I want to constrain my system (attached) for input and output delays.

The input delay is straightforward. But I have my doubts about the output delay.

This is what I did for the input delay:

create_clock -name clock_in -period 10.000 [get_ports {clock_in}]

set_input_delay -clock clock_in -max 1.0 [get_ports data_in]

set_input_delay -clock clock_in -min 0.1 [get_ports data_in]

Now, what should I do to specify the output delay ?

What clock should be used for reference ?

clock_in ?

set_output_delay -clock clock_in -max -1.0 [get_ports data_out]

set_output_delay -clock clock_in -min -0.1 [get_ports data_out]

Or clock_out ?

Now, what should I do to specify the output delay ?

set_output_delay -clock clock_out -max -1.0 [get_ports data_out]

set_output_delay -clock clock_out -min -0.1 [get_ports data_out]