the present disclosure relates to a hardware protocol stack , and more particularly , to a hardware protocol stack to which a user - defined protocol is applicable . the present disclosure compares header information stored in a register unit with header information of a received frame , and determines a processing of the received frame on the basis of a comparison result . also , according to a determined frame process method , data of the received frame is processed based on a logic according to the header information , it is stored at a designated position , or a response frame is transmitted .