Vlsi Technology, Inc.

Other

Steven D Thomas

Vincent J Coli

Bryan C Doi

Vito D Giglio

The present invention relates to an implementation of adiabatic circuitry using a pipeline structure which allows for simultaneous evaluation of cascaded functions, which does not require each logic function to be implemented in dual complimentary circuitry, which does not require reversible logic functions, which does not require the use of diodes to insure adiabatic current flow, and which can be implemented using MOS technology. A significant feature of the present invention relates to use of a six-phase clock cycle associated with six phases of circuit operation including, in order, a precharge phase, a precharge disable phase, an evaluate phase, a hold phase, a precharge enable phase and a guard phase. Another significant feature of the present invention relates to simultaneous evaluation of cascaded logic functions during a single phase of operation.

Precharged adiabatic pipelined logic

A security system is used for programmable read-only memory locations within a very large scale integrated (VLSI) circuit. In a first security bit memory location there is stored a first security data bit. The first security data bit has a first value when the first security bit memory location is unprogrammed and a second value when the first security bit memory location is programmed. In a second security bit memory location there is stored a second security data bit. The second security data bit has the first value when the second security bit memory location is unprogrammed and the second value when the second security bit memory location is programmed. A selection logic is electrically coupled to the first security bit memory location and the second security bit memory location. The selection logic selects no security data bit, the first security data bit or the second security data bit to be used to generate a security access signal. An access logic allows and prevents direct access, by any device outside the VLSI circuit, to the programmable read-only memory locations in response to the security access signal. The access logic prevents any device outside the VLSI circuit direct access to the programmable read-only memory locations when the selection logic selects no security data bit, when the selection logic selects the first security bit and the first security data bit has the second value, or when the selection logic selects the second security bit and the second security data bit has the second value.

Verifiable security circuitry for preventing unauthorized access to

The present invention relates to an implementation of domino logic using a logic cell which is not limited to the use of positive logic functions, and which can be implemented using MOS technology. A significant feature of the present invention relates to use of a single clock cycle to generate separate clock phases for a first function (e.g., carry function of a full-adder logic cell) and a second function (e.g., sum function in the full-adder logic cell). The separate clock phase used to gate the second function corresponds to a delayed version of the clock phase used to gate the first function, wherein the clock delay corresponds to a delay through the first function. In one exemplary embodiment, the delay can be made equal to that of the first function by using circuitry identical to that of the first function to create the delay period.

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Palmdale, CA, United States of America

Steven D Thomas