Architectural Considerations in the Design of Special-Purpose Machines,

摘要

In the first part of this thesis, the architectural development of a specific machine is presented. The experiences gained during this design project indicate that there is a 'best' system architecture for a given problem. Design options become available only on lower design levels, mainly in control units. The second part of the paper analyzes the choice between microprogrammed and hardwired realizations of control units. A model which predicts the costs of equivalent microprogrammed and hardwired control units is developed. This model predicts that the cost of a hardwired control unit will increase faster than that of its microprogrammed counterpart as the control signals which must be emitted become more complex. From the same foundations, a model for the reliability of both methods can be obtained. This model predicts that the reliability of a microprogrammed control is nearly independent of the control sequence. Hardwired control units, however, suffer from decreased reliability as control complexity grows. (Author)