HYBRID CONTENT ADDRESSABLE MEMORY
First Claim
1. A content addressable memory device comprising:
- rows of first matchlines precharged to a voltage level corresponding to a miss condition;
ternary cells connected in parallel to each of the first matchlines;
rows of second matchlines precharged to a voltage level corresponding to a miss condition;
binary cells connected in parallel to each of the second matchlines, the binary cells being smaller in size than the ternary cells and operable simultaneously with the ternary cells; and
searchlines connected to the ternary cells of the rows of first matchlines and to the binary cells of the rows of second matchlines.
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Accused Products
Abstract
A CAM device memory array having different types of memory cells is disclosed. A CAM device memory array is subdivided into at least two different portions, where each portion uses only one particular type of CAM cell, and each portion is dedicated to storing a particular type of data. In particular, at least one portion consists of binary CAM cells and the other portion consists of ternary CAM cells. The portions can be partitioned along the row, or matchline, direction or along the bitline direction. Since particular data formats only require predefined bit positions of a word of data to be ternary in value, the remaining binary bit positions can be stored in binary CAM cells. Therefore, the CAM device memory array will occupy an overall area that is less than memory arrays of the same density consisting exclusively of ternary CAM cells.
54 Citations
17 Claims
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1. A content addressable memory device comprising:
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rows of first matchlines precharged to a voltage level corresponding to a miss condition; ternary cells connected in parallel to each of the first matchlines; rows of second matchlines precharged to a voltage level corresponding to a miss condition; binary cells connected in parallel to each of the second matchlines, the binary cells being smaller in size than the ternary cells and operable simultaneously with the ternary cells; and searchlines connected to the ternary cells of the rows of first matchlines and to the binary cells of the rows of second matchlines. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A content addressable memory (CAM) device comprising:
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a first matchline row prechargeable to a first voltage level corresponding to a first miss condition; a second matchline row prechargeable to a second voltage level corresponding to a second miss condition; a ternary CAM cell coupled to the first matchline; a binary CAM cell coupled to the second matchline, the binary CAM cell being smaller than the ternary CAM cell and the binary CAM cell being simultaneously operable with the ternary CAM cell; and the ternary CAM cell and the binary CAM cell being coupled to a common bitline and searchline. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification