Comparative Analysis of the Use of Dynamic and Static Shift Registers in Digital Signal Processors.
Abstract
High-density shift-register devices are used in many present-day data-processing systems such as radar digital signal processors. The number of bits of shift-register storage required increases with the need for greater radar range and resolution capability. The large-scale integrated (LSI) MOS circuit technology currently offers the possibility of shift registers of tens of thousands of bits per cubic inch with average power dissipation below 200 microwatt per bit. These units can be implemented for dynamic or static operation with inherent higher power dissipation in the latter case, due to the additional circuitry required. The key characteristics of these implementations are the need for continuous clocking above some minimum frequency in the dynamic case and negligible power dissipation during quiescent operation in the static case. This report analyzes the relative power dissipation of dynamic and static models of complimentary MOS (CMOS) shift registers as applied to a digital-feedback-integrator signal processor for the practical case of a nonunity processing duty factor. The concepts of shift-register multiplexing and staggering for the purpose of power-dissipation reduction are described and extensively analyzed. It is shown that in practice the amount of reduction in dissipated power is limited by the power required by the additional circuitry used to achieve multiplexing or staggering. The relative power dissipation for each of the different configurations is derived for the dynamic- and static-register models. For the models considered, the static-register configurations dissipate less power than the dynamic-register configurations, due to the recirculation required in the dynamic case.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 26, 1972
- Accession Number
- AD0906730
Entities
People
- Lawrence M. Leibowitz
Organizations
- United States Naval Research Laboratory