Low power MOS RAM address decode circuit
AssigneeMotorola, Inc.
InventorAlan Richard Bormann
Life of this patent
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Abstract
An MOS random access memory chip utilizes a column decode circuit scheme in which a signal derived from a chip select input of the random access memory chip is coupled to the gate of a switching device of dynamic IGFET NOR gates utilized to accomplish the column decoding function. This prevents the bit sense column selection conductor from being affected when an internal column selection clock signal is generated. This results in a substantial savings in power dissipation which would be required if it were necessary to provide circuitry to disable the internal column selection clock generator circuit during an unselected memory cycle.
Claims2
In a MOS semiconductor random access memory chip including a plurality of address inputs, a chip selection input, and a plurality of sense lines, an address decode circuit coupled between first and second voltage conductors comprising:
- a dynamic NOR gate responsive to said plurality of address inputs having an output and including a first MOSFET means coupled between said output and said first voltage conductor for precharging said output, and a plurality of input MOSFETs responsive to said address inputs coupled between said output and said second voltage conductor for discharging said output if said dynamic NOR gate is not selected by said plurality of address inputs;
- sense line selection circuit means coupled to said output for effecting selection of one of said sense lines in response to said dynamic NOR gate on the condition that said dynamic NOR gate is selected;
- Mosfet means responsive to said chip selection input coupled between said output and said second voltage conductor for discharging said output on the condition that said MOS semiconductor random access memory chip is unselected to avoid selection of said one of said sense lines.
Dependencies are inferred from the claim text.