Standard Microsystems Corporation

Henry W Pechar

James D Sproch

Tak P Li

A dynamic read only memory (ROM) which comprises a memory select precharge section, a memory select section, a memory section, a memory precharge section and a plurality of grounding devices. The ground reference for the pulldown transistors is selectively activated at an appropriate time such that the memory sections are active only for a relatively brief portion of the memory cycle, thereby reducing dc power consumption and simplifying the driver circuit.

Virtual ground read only memory

A circuit is disclosed for separating clock and data signals from a combined data-clock stream derived from a disk. The circuit includes two memories or shift registers which sample the incoming data at alternate portions of a reference clock. The outputs of the registers are applied to a decoder which identifies which of the two registers contains the data portion and which contains the clock portion with the missing clock pattern. That determination, in turn, controls the generation of the synchronization signal for the circuit and also establishes a control signal that selects data from the other of the registers.

Dual edge clock address mark detector

A method and circuit arrangement are disclosed for foiling an attempt to copy an MOS integrated circuit by implementing in the circuit an additional pseudo MOS device, which from its location in the circuit would appear to a would-be copier to be an enhancement-mode device. However, the pseudo-auxiliary MOS device is implemented as a depletion-mode device and is connected in the circuit so that when it is implemented by the copier as an enhancement-mode device. the overall circuit will not be functional.

Circuit to prevent pirating of an MOS circuit

A clock generator for producing nonoverlapping clocks from an input clock includes an MOS depletion-mode device receiving the input clock at an input. The output of the depletion-mode device, which constitutes one of the clocks, is also applied to one input of a NOR gate, the other input of which is the input clock. The output of the NOR gate is the second clock.

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Commack, NY, United States of America

Henry W Pechar