18 - The Description and Use of Register Transfer Modules (RTMs)

Abstract

This chapter describes register transfer modules (RTMs) and their use. In the design of digital systems, the problem formulation and the design solution are most likely carried out at a register transfer concept level. RTMs provide a basic set of modules for high-level digital systems design. Digital system design is carried out entirely in terms of the modules; combinational and sequential switching circuit design is not used. Design time is significantly less than with conventional logical design. The Register Transfer Modules make extensive use of MSI circuitry and can use LSI circuitry to provide even lower cost modules. A register transfer language, instruction set processor, is used to define the register transfer operations of the RTMs. The RTM system consists of about 20 different modules and a method of interconnecting modules via a common bus that carries data and timing interlock signals for the register transfers. The chapter highlights the important design variables for RTMs, together with many of the constraints.