Memory elements with dynamic pull-up weakening write assist circuitry
First Claim
1. An integrated circuit, comprising:
- a pair of bit lines;
a column of memory cells coupled to the pair of bit lines, wherein each memory cell in the column of memory cells includes cross-coupled inverters with positive power supply terminals, and wherein the positive power supply terminals of each memory cell in the column of memory cells are coupled to only a first pull-up transistor having a gate terminal that receives an adjustable control signal; and
a pull-up weakening control circuit that outputs the adjustable control signal, the pull-up weakening control circuit drives the adjustable control signal to a ground power supply level during read operations and temporarily elevates the adjustable control signal above the ground power supply level during write operations.
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Accused Products
Abstract
Integrated circuits with an array of memory cells are provided. Each memory cell may include at least one pair of cross-coupled inverters, write access transistors, and optionally a separate read port. The cross-coupled inverters in each memory cell may have a positive power supply terminal. The positive power supply terminal of each memory cell along a given column in the array may be coupled to a corresponding pull-up transistor. The pull-up transistor may receive a control signal from a pull-up weakening control circuit. The control signal may be temporarily elevated during write operations and may otherwise be driven back down to ground to help optimize read performance. The pull-up weakening control circuit may be implemented using a chain of n-channel transistors or a resistor chain.
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Citations
19 Claims
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1. An integrated circuit, comprising:
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a pair of bit lines; a column of memory cells coupled to the pair of bit lines, wherein each memory cell in the column of memory cells includes cross-coupled inverters with positive power supply terminals, and wherein the positive power supply terminals of each memory cell in the column of memory cells are coupled to only a first pull-up transistor having a gate terminal that receives an adjustable control signal; and a pull-up weakening control circuit that outputs the adjustable control signal, the pull-up weakening control circuit drives the adjustable control signal to a ground power supply level during read operations and temporarily elevates the adjustable control signal above the ground power supply level during write operations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of operating an integrated circuit having a pull-up transistor that is shared among a column of memory cells, the method comprising:
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with a pull-up weakening control circuit, outputting a control signal at a ground power supply voltage level to the pull-up transistor during read operations; and with the pull-up weakening control circuit, temporarily adjusting the control signal to be different than the ground power supply voltage level during write operations. - View Dependent Claims (11, 12, 13, 14)
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15. An integrated circuit, comprising:
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a group of memory cells each of which includes inverting circuits having power supply terminals; a single pull-up transistor that is coupled to the power supply terminals of the inverters in each memory cell in the group of memory cells, wherein the pull-up transistor is shared among the group of memory cells; and a pull-up weakening control circuit that is configured to output a control signal at a first predetermined voltage level to the pull-up transistor in a first mode and that is configured to output the control signal at a second predetermined voltage level that is different than the first predetermined voltage level to the pull-up transistor in a second mode during write operations. - View Dependent Claims (16, 17, 18, 19)
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Specification