Voltage protection of write protect cams
AssigneeAdvanced Micro Devices, Inc.
InventorsSantosh K. Yachareni, Edward V. Bautista, Jr.
Life of this patent
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Abstract
The present invention discloses systems and methods for providing voltages during programming to the control gates of write protect CAMS. Upon entering a write protect CAM programming mode, at least one voltage supply circuit is activated to supply the predetermined voltage for the control gates of the write protect CAMS. When the write protect CAMS are programmed, a gate control circuit transfers a programming voltage to the control gates of the write protect CAMS. Following programming and verification of the write protect CAMS, the gate control circuit holds the control gates of the write protect CAMS at a ground voltage level.
Claims22
A method of controlling the voltage applied to a plurality of write protect CAMS in a memory device, comprising the steps of:
- generating a predetermined voltage with at least one voltage supply circuit;
- transferring said predetermined voltage with a gate control circuit to at least one control gate of a write protect CAM;
- and
- connecting said control gate of said write protect CAM to a ground voltage level with said gate control circuit when said predetermined voltage is not being transferred to said control gate of said write protect CAM.
A method of controlling the voltage applied to a plurality of write protect CAMS in a memory device, comprising the steps of:
- generating a programming voltage with at least one voltage supply circuit;
- transferring said programming voltage to said plurality of write protect CAMS with a gate control circuit for a first predetermined amount of time;
- generating a program verify voltage with said voltage supply circuit;
- transferring said program verify voltage to said write protect CAMS with said gate control circuit for a second predetermined amount of time;
- and
- connecting said write protect CAMS to a ground voltage level with said gate control circuit.
A voltage supply system for programming a plurality of write protect CAMS in a memory device, comprising:
- at least one voltage supply circuit for generating a predetermined voltage;
- a gate control circuit electrically connected with the output of said voltage supply circuit and the control gates of said write protect CAMS, wherein said gate control circuit is operable to transfer said predetermined voltage to the control gates of said write protect CAMS only during programming and holds the control gates of said write protect CAMS at a ground voltage level when not programming said write protect CAMS.
Dependencies are inferred from the claim text.