发明名称 |
TWO PHASE SEARCH CONTENT ADDRESSABLE MEMORY WITH POWER-GATED MAIN-SEARCH |
摘要 |
Low leakage CAMs and method of searching low leakage CAMs. The method includes performing a pre-search and compare on a small number of pre-search bits with pre-search CAM cells powered to normal voltage levels at all times while the main-search CAM cells are powered to a lower voltage level. Only if a match is detected on the pre-search bits are the main-search CAM cells powered-up to normal voltage levels and the search of the main-search bits activated. The main-search CAM cells are powered to normal voltage levels during read and write operations. |
申请公布号 |
US2014192579(A1) |
申请公布日期 |
2014.07.10 |
申请号 |
US201313733973 |
申请日期 |
2013.01.04 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
Arsovski Igor;Fragano Michael T.;Hebig Travis R. |
分类号 |
G11C15/04;G11C15/00 |
主分类号 |
G11C15/04 |
代理机构 |
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代理人 |
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主权项 |
1. A content addressable memory, comprising:
an array of content addressable memory cells arranged in rows and columns and partitioned into a pre-search section and a main-search section; and each row of content addressable memory cells including:
a row of content addressable memory cells of said pre-search section connected between a first positive voltage rail and ground and connected to a pre-matchline of said content addressable memory;a corresponding row of content addressable memory cells of said main-search section connected to a light-sleep circuit, to ground and to a main-matchline of said content addressable memory, said light-sleep circuit configured to connect content addressable memory cells of said main-search section to a second positive voltage rail in a light-sleep state and to connect content addressable memory cells of said corresponding row of content addressable memory cells of said main-search section to said first positive voltage rail in an awake state;a pre-search circuit connected to a pre-search matchline and (i) configured to perform a pre-search of said row of content addressable memory cells of said pre-search section and (ii) configured, only if a match is found, place said light-sleep circuit in said awake state; anda main-search circuit connected to a main matchline and configured to activate a main-search of said row of content addressable memory cells of said main-search section only if a match is found by said corresponding pre-search circuit. |
地址 |
Armonk NY US |