发明名称 Method and apparatus for adjusting control circuit pull-up margin for content addressable memory (CAM)
摘要 A method for determining a desired operating impedance for a computer memory circuit is disclosed, the computer memory circuit having a plurality of discrete, selectively adjustable impedance values associated therewith. In an exemplary embodiment of the invention, the method includes applying, to a reference circuit, a test impedance value to a reference circuit. The test impedance value is controlled by a binary count. A determination is made, based upon the applied test impedance value, whether the reference circuit is in either a first state or a second state. The binary count is incremented if the reference circuit is in the first state and decremented if the reference circuit is in the second state. A condition is determined in which the reference circuit oscillates between the first state and said second state, and a pair of binary count values is stored. The desired operating impedance for the computer memory circuit corresponds to the lower of the stored pair of binary count values.
申请公布号 US2003198071(A1) 申请公布日期 2003.10.23
申请号 US20030421963 申请日期 2003.04.23
申请人 INTERNATIONAL BUSINESS MACHINES CORPORATION 发明人 TOWLER FRED J.;WISTORT REID A.;ROTELLA JASON
分类号 G11C15/00;G11C15/04;G11C29/50;(IPC1-7):G11C15/04;G11C29/00 主分类号 G11C15/00
代理机构 代理人
主权项
地址