The specified port has in infinite rate; this means that it is probably driven by a constant block that has an inf rate. When rate coloring is enabled, this will show up as pink. To enable sample time colors, on the model choose Display>Sample Time>Colors.
You need to chance the Simulink rate of the driving signal. If it's being directly driven by a data source, simply change the rate from "inf" to any current rate in your system. If your base rate is e.g. 1, try setting the source rate to 1 instead of inf. If the input is not driven directly by a source, you can either figure out how to make your logic drive a time-varying value, or you can insert a rate transition block immediately before the HDL input port.
