what is register transfer language (RTL)

A register transfer language (RTL) is “a set of symbolic notation” used to describe the microoperation transfers among registers. The term “register transfer” implies that we have the hardware logic necessary to perform a stated microoperation and transfer the results to the same or another register in one clock cycle. Not only is a RTL a convenient tool for describing the internal organization of digital computers in a concise and definitive manner, it can also be used to facilitate the design process of digital systems. Unlike a programming language a RTL is directly related to and cannot be separated from the registers and other hardware operations that it defines.