Lsi Logic Corporation

Myron J Buer

Yauh-Ching Liu

Ruggero Castagnetti

Ramnath Venkatraman

Thomas R Wik

Gary K Giust

Mike T Liang

Gordon W Priebe

Franklin Duan

Weiran Kong

Kevin R LeClair

Steven Michael Peterson

Robin H Passow

Sudhakar Sabada

Ken Redding

Minh Tien Nguyen

A method of forming a memory cell according to the present invention. A first pass gate transistor is formed of a first transistor type. The first pass gate transistor has a gate oxide with a first thickness. The source of the first pass gate transistor is electrically connected to a first bit line, and the drain of the first pass gate transistor is electrically connected to a first state node. The gate of the first pass gate transistor is electrically connected to a memory cell enable line. A second pass gate transistor is also formed of the first transistor type. The second pass gate transistor also has a gate oxide with the first thickness. The source of the second pass gate transistor is electrically connected to a second bit line, and the drain of the second pass gate transistor is electrically connected to a second state node. The gate of the second pass gate transistor is electrically connected to the memory cell enable line. A first state node transistor is also formed of the first transistor type. The first state node transistor has a gate oxide with a second thickness. The source of the first state node transistor is electrically connected to the first state node, and the drain of the first state node transistor is electrically connected to a ground line. The gate of the first state node is electrically connected to the second state node. A second state node transistor is also formed of the first transistor type. The second state node transistor also has a gate oxide with the second thickness. The source of the second state node transistor is electrically connected to the second state node, and the drain of the second state node transistor is electrically connected to the ground line. The gate of the second state node is electrically connected to the first state node.

Single channel four transistor SRAM

A method is provided for using twisted bit or signal lines and routing restrictions on the logic signal lines to pass logic signals over an on-chip memory. In one embodiment, the memory array includes complementary bitlines which are provided with periodic twists, and the logic signal routing is restricted in that logic signals are either routed perpendicular to the bit lines, or they are routed parallel to the bit lines in such a manner as to ensure equal coupling to both B and B'. The equal coupling is provided by either restricting the length of the logic signal line segment to an integral number of twist wavelengths, or by placing the logic signal line segment so that its midpoint rests on a twist centerline. In another embodiment, the memory array includes bitlines running parallel to a bitline axis, and complementary logic signal lines are routed in pairs. The logic signal routing is restricted in that logic signals are either routed perpendicular to the bitline axis, or they are routed parallel to the bitlines in such a manner as to ensure equal coupling to both B and B'. The equal coupling is provided by either placing a twist at the midpoint of the complementary logic signal line segment, or by placing periodic twists in the complementary logic signal line segment and restricting the length of the segment to an integer number of twist wavelengths.

Method and system which permits logic signal routing over on-chip

A semiconductor memory layout definition for connection to a power supply bus in an integrated circuit layout pattern. The layout definition includes an outline and a plurality of power supply conductor segments within the outline. At least one of the power supply conductor segments has a direct strap identifier which indicates a desired attachment to the power supply bus. The direct strap identifier is passed to a routing design tool which routes a direct strap conductor from the power supply bus to the power supply conductor segments having the direct strap identifier.

Memory having direct strap connection to power supply

A multiple match detection circuit including an array of N and P-channel pull-up and pull-down devices receiving a corresponding array of hit line signals for developing complementary bit line signals, which are provided to the respective inputs of a differential comparator. Respective buffers drive the bit line signals to a maximum voltage differential in normal mode. For each hit line asserted, the pull-up and pull-down devices modify the voltage of the corresponding bit line voltage between the bit lines by an incremental amount, thereby decreasing the differential. Any single hit line does not cause enough of a voltage change to reverse the polarity of the differential voltage between the bit lines. However, if more than one hit line is asserted, the combined incremental change of voltage due to activation of two or more pull-up and pull-down devices is greater than the maximum voltage differential between the bit line signals asserted by the buffers, causing the bit line differential voltage to reverse polarity. The differential comparator detects the reversal of polarity of the bit line differential voltage and asserts an error signal. The multiple detection circuit further includes a transmission gate, which selectively equalizes charge on the bit lines, and isolation devices, which provide level shifting, prior to detection by the differential amplifier to thereby increase the speed of detection.

High speed method and apparatus for detecting assertion of multiple

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Shakopee, MN, United States of America

Myron J Buer