Signal processing device and signal processing system

The present disclosure provides a signal processing apparatus and a signal processing system capable of easily communicating data with two devices. A signal processing device according to the present disclosure is provided with: a first terminal to which one of a clock signal and a data signal is input; a second terminal to which the other of the clock signal and the data signal is input; a storage unit that sets an address map that defines an address at which data is permitted to be written and an address at which data is prohibited to be written; a specifying unit that specifies the address map set in the storage unit; and a processing unit that writes the data based on the data signal to the storage unit in accordance with the address map specified by the specifying unit. The specifying unit specifies a first address map when a clock signal is input to the first terminal and a data signal is input to the second terminal, and specifies a second address map different from the first address map when the data