A communication processor that is compatible with a plurality of communication protocols while limiting increases in circuit scale is provided. The communication processor includes a computational processing circuit resource having a plurality of programmable function units (FUs). An operation mode determination unit determines an operation mode indicating a communication protocol application state. A permitted processing time determination unit determines a permitted processing time in accordance with the determined operation mode. In accordance with the permitted processing time, a resource allocation unit divides the plurality of FUs and allocates computational resources for each communication protocol indicated by the operation mode. A region controller controls the allocated computation resources. The computational processing circuit resource outputs data from after the computational processing at the timing when the computation processing ends.