Lsi Logic Corporation

Lsi Corporation

Chang Ho Jung

Jeffrey Scott Brown

Jeff S Brown

Craig R Chafin

A self-timed memory array is disclosed, in which segmentability and metal-programmability are supported while minimizing layout space. Self-timing row decoder circuits are placed at the top and bottom of the array adjacent to respective I/O blocks. A self-timing signal is routed from the top (resp. bottom) of the array to a point halfway down (resp. up) the memory array and then back to a self-timing row decoder at the top (resp. bottom) of the array. The same approach may also be used to account for the bitline wire delay from the bottom (resp. top) of the array to the sense amplifiers in the I/O block. Further flexibility in wire routing is provided by eliminating metal routing layers from unneeded memory cells, and a programmable gate array may be used to allow an arbitrary word size to be chosen for the memory.

Metal programmable self-timed memories

A clock generating circuit for a pseudo dual port memory incorporates feedback, delays, and latches to ensure that the write (read) operation clock pulse is sufficiently spaced in time from the read (write) operation clock. The clock generating circuit receives an external clock, a read enable signal, a write enable signal, and a reset signal as inputs. Advantages include minimization of the clock cycle time and operation unaffected by the duty ratio of an external clock. Delay circuitry may be added such that the generated clock signal has sufficient fan out and is sufficiently stable.

Clock generator for pseudo dual port memory

The present invention is a method and system for providing a scalable memory building block device. The memory building block device includes a plurality of separate memory arrays, decode logic for selecting only one bit from the plurality of memory arrays, and output means for providing only one bit as an output of the memory building block device, such that the memory building block device generates as its output only one bit.

Method and device for a scalable memory building block

A method and apparatus is provided for replacing defective storage cells within a memory device having twisted bit lines. If a defective storage cell is discovered, the row containing that storage cell can be re-mapped to the neighboring row or the memory array. Each successive neighboring row is also re-mapped to succeeding neighboring rows by incrementing or decrementing the row addresses. This will cause the addresses to essentially shift one address value toward the redundant set of rows, and one redundant row will be subsumed for every defective row within the array. Whenever an address is shifted across a twist region, the data of that address is purposely inverted in binary voltage value (i.e., converted from a binary 1 to a binary 0, and vice versa) to accommodate the twisting of the true and complementary bit line locations.

Method and apparatus for replacing a defective cell within a memory device having twisted bit lines

The present invention describes a multi-stage decoder and method of decoding utilizing a pseudo NAND or pseudo AND gate in one of the stages. This invention presents a decoder comprising a first stage circuit having two or more first inputs which generates one or more first outputs; and a second stage circuit having at least one second input and at least one second output, wherein the one or more first outputs are the same as the at least one second input, wherein at least one of the group consisting of the first stage circuit and the second stage circuit includes either a pseudo AND gate or a pseudo NAND gate. This invention presents a method of decoding, comprising the steps of generating a signal responsive to two or more address bits and enabling a decoder by the generated signal.

Address decoder with pseudo and or pseudo nand gate

The present invention discloses a novel method and system for accessing a semiconductor device at multiple operating speeds. The novel method and system of the present invention allows access to a semiconductor device by a pipeline circuit in which modification of the pipeline circuitry is not required to achieve multiple operating speeds. An example of the invention may be the utilization of an internal clock to control internal pipeline which may allow adjustment of an effective operating speed of a semiconductor device.

Design simplicity of very high-speed semiconductor device

A compensation capacitance is utilized in a multiport memory device to compensate for the effect of bit line coupling capacitance. A first compensation capacitance is applied between a read bit line and a write bar bit line, and a second compensation capacitance is applied between a write bit line and a read bar bit line to compensate for the effect of bit line capacitance that adversely affects the differential voltage swing at a the read bit line. In one embodiment, the compensation capacitances are equal to the value of the compensation capacitances. In an alternative embodiment, each compensation capacitance comprises two compensation capacitors additively combined in parallel each having a value of one-half of the coupling capacitance. The compensation capacitance may be variable so that compensation of the coupling capacitance may be optimized after fabrication of the integrated circuit.

Compensation capacitance for minimizing bit line coupling in multiport memory

A memory device including a plurality of memory cells, a plurality of bit lines, a plurality of bit line sense amplifiers, a plurality of column port gates, and a column decoder connected to a multiple of five column port gates. Each of the bit line sense amplifiers is connected to at least one of the bit lines and to at least one of the memory cells. Each of the column port gates is connected to at least one of the bit line sense amplifiers. The column decoder provides signals to the column port gates to which it is connected to select corresponding bit lines connected to the column port gates.

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Ft. Collins, CO, United States of America

Chang Ho Jung