Atmel Corporation

Liqi Wang

Philip S Ng

Jinshu Son

Minh V Le

Johnny Chan

Sai Kai Tsang

Kris Li

An electronic test structure and method for testing non-volatile memory cells. The structure includes a first transistor coupled in series to a floating gate transistor whereby a source of the first transistor is coupled to a positive power supply voltage and a source of the floating gate transistor is coupled to a power supply ground. A gate of the first transistor is further coupled to a source of the first transistor. A second transistor is coupled in series with a memory cell with a source of the second transistor coupled to a positive power supply voltage and a gate of the second transistor is coupled to the drain of the first transistor.

Indirect measurement of negative margin voltages in endurance testing of EEPROM cells

A method for preventing snap-back in a circuit including at least one MOS transistor having a parasitic bipolar transistor associated with it includes coupling a circuit node including at least one source/drain node of the at least one MOS transistor to a bias-voltage circuit and enabling the bias-voltage circuit to supply a potential to the at least one source/drain node of the at least on MOS transistor, the potential having a magnitude selected to prevent the parasitic bipolar transistor from turning on.

Apparatus and method for preventing snap back in integrated circuits

Circuitry for testing a power-on-reset circuit in an integrated circuit includes a high-voltage detector coupled to a first I/O pad of the integrated circuit. A power-on-reset circuit in the integrated circuit has an output coupled to a driver circuit that is powered by the high-voltage. A second I/O pad of the integrated circuit is coupled to the output of the driver circuit. The driver circuit may be enabled by a signal provided on a third I/O pad of the integrated circuit.

Method and apparatus to test the power-on-reset trip point of an integrated circuit

A bitline selection network is composed of a plurality of bitlines and a plurality of global bitlines. The bitlines are grouped into bytes with eight bitlines per byte. The bitlines provide access to memory cells for read and write operations. A bitline is connected to a global bitline through a bitline select transistor. Each of the bitline select transistors is activated one at a time by a bitline select controller. Activation of each bitline select transistor provides a connection to a source line, which in turn connects to a sense amplifier and a write data loading logic block. The sense amplifier and the write data loading logic block are used in read and write operations respectively.

Memory data access scheme

Fuse data used to configure ancillary circuits used with a non-volatile serial memory core are stored in locations within the memory core. As a first opcode or word is sent on a serial bus to the memory, a logic circuit intercepts the word and generates read fuse enable pulses that fetch the fuse data and configure the ancillary circuits before the last bit of the first command byte arrives. If a read operation is designated, the memory circuits are configured to read. If a write operation is designated, further fuse data is fetched from the memory core to configure ancillary circuits for writing. The fuse data is written to the memory core at the time of circuit manufacture thereby obviating the need for separate storage locations.

Fuse data storage system using core memory

A multiplexer circuit in a memory organized into page-portions has a plurality of bit-select multiplexers configured to couple a plurality of page-portion global bitlines to a sense amplifier input. A plurality of column address lines organized into data bytes comprises each page-portion. A plurality of column multiplexers couple the data bytes to the page-portion global bitlines such that each of the address lines comprising the data byte is coupled to one of the page-portion global bitlines.

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Sunnyvale, CA, United States of America

Liqi Wang