Advanced Micro Devices Corporation

Azrul Halim

Colin Stewart Bill

Edward V Bautista, Jr

Ken Cheong Cheah

Feng Q Pan

Darlene G Hamilton

Weng Fook Lee

Syahrizal Salleh

For generating a margining voltage for biasing a gate of a CAM (content addressable memory) cell of a flash memory device fabricated on a semiconductor wafer, a high voltage source is provided with a voltage generator fabricated on the semiconductor wafer. A low voltage source is provided from a node coupled to the voltage generator fabricated on the semiconductor wafer. For example, the voltage generator for providing the high voltage source includes a voltage regulator and a charge pump fabricated on the semiconductor wafer, and the low voltage source is the ground node. In addition, a first transistor is coupled to the high voltage source, and a second transistor is coupled to the low voltage source. A first resistor is coupled between the first transistor and an output node, and a second resistor coupled between the second transistor and the output node. The margining voltage is generated at the output node. The first resistor and the second resistor form a resistive voltage divider at the output node between the high voltage source and the low voltage source when the first transistor and the second transistor are turned on. A logic circuit turns on the first transistor and the second transistor when a first set of control signals indicate that program margining of the CAM cell during a BIST (built-in-self-test) mode is invoked. The first transistor, the second transistor, the first resistor, the second resistor, and the logic circuit are fabricated on the semiconductor wafer. In another embodiment of the present invention, the logic circuit turns off the first transistor and turns on the second transistor such that the output node discharges to a voltage of the low voltage source for erase margining of the CAM cell.

Generation of margining voltage on-chip during testing CAM portion of flash memory device

In a method and system for repairing defective flash memory cells fabricated on a semiconductor substrate, a repair controller and a plurality of voltage sources are fabricated on the semiconductor substrate. The repair controller controls the voltage sources to apply programming voltages on respective CAM (content addressable memory) flash memory cells in a JUICE state for replacing the defective flash memory cells with a corresponding redundancy element of flash memory cells. In addition, a FAILREP logic is fabricated on the semiconductor substrate for entering a HANG state if no redundancy element of flash memory cells is available or if the defective flash memory cells have been previously repaired.

On-chip repair of defective address of core flash memory cells

There is provided a tester interface circuit for use with a BIST state machine and a method for micro-architectural implementation of the same so as to enable cycling through a BIST test. The tester interface circuit includes a storage device, a logic decoder, a set/clear mechanism, and a polling logic device. The tester interface circuit is implemented with a minimum amount of chip area on a semiconductor IC.

Method of micro-architectural implementation of interface between bist state machine and tester interface to enable bist cycling

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Penang, Malaysia

Azrul Halim