DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Rapid and Accurate Timing Simulation of Radiation-Hardened Digital Microelectronics Using VHDL
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
This dissertation presents the development of a fast, accurate, timing simulation capability based on VHSIC Hardware Description Language VHDL without the use of back annotation of timing delay information. This VHDL-based timing simulator is intended for use with radiation-hardened microelectronics in simulating timing of circuit operation in pre-radiation, post-radiation 1 MradSi total dose, and ionizing dose radiation environments. Development of the timing models are presented. The implementation of the timing models are incorporated into a VHDL library composed of basic logic gates and flip-flops. Simulations of complex circuits were run in SPICE and VHDL to assess the timing accuracy and simulation run time of the VHDL-based timing simulator versus SPICE. Results of the simulations are presented. Final evaluation of the simulator included testing of a microprocessor control unit. In all cases, the VHDL-based simulation ran over two orders of magnitude faster than the equivalent SPICE simulation. In the pre- and post-radiation environment, accuracy estimates are usually within five percent and never exceed 12 percent. Worst-case timing estimate errors increase above 15 percent for dose rates above 1.Ox1Oexp 11 radsSi per second. This VHDL-based timing simulator represents an improvement over SPICE in the ability to quickly simulate complex circuits. CMOS Logic simulation, Logic circuit simulation, Radiation-hardened microelectronics, Transient radiation effects, VHDL.
APPROVED FOR PUBLIC RELEASE