Invention Grant
US07864625B2 Optimizing SRAM performance over extended voltage or process range using self-timed calibration of local clock generator
有权
使用本地时钟发生器的自定时校准优化扩展电压或过程范围内的SRAM性能
- Patent Title: Optimizing SRAM performance over extended voltage or process range using self-timed calibration of local clock generator
- Patent Title (中): 使用本地时钟发生器的自定时校准优化扩展电压或过程范围内的SRAM性能
-
Application No.: US12244286Application Date: 2008-10-02
-
Publication No.: US07864625B2Publication Date: 2011-01-04
- Inventor: Gary D. Carpenter , Jente B. Kuang , Kevin J. Nowka , Liang-Teck Pang
- Applicant: Gary D. Carpenter , Jente B. Kuang , Kevin J. Nowka , Liang-Teck Pang
- Applicant Address: US NY Armonk
- Assignee: International Business Machines Corporation
- Current Assignee: International Business Machines Corporation
- Current Assignee Address: US NY Armonk
- Agent Libby Z. Handelsman; Jack V. Musgrove
- Main IPC: G11C8/18
- IPC: G11C8/18 ; G11C8/00 ; G11C7/00

Abstract:
A delay circuit has a fixed delay path at a lower voltage level, a level converter, and an adjustable delay path at a higher voltage level. The fixed delay path includes an inverter chain, and the adjustable delay path includes serially-connected delay elements selectively connected to the circuit output. In an application for a local clock buffer of a static, random-access memory (SRAM), the lower voltage level is that of the local clock buffer, and the higher voltage level is that of the SRAM. These voltages may vary in response to dynamic voltage scaling, requiring re-calibration of the adjustable delay path. The adjustable delay path may be calibrated by progressively increasing the read access time of the SRAM array until a contemporaneous read operation returns the correct output, or by using a replica SRAM path to simulate variations in delay with changes in voltage supply.
Public/Granted literature
Information query