Invention Grant
US07646668B2 Maintaining dynamic count of FIFO contents in multiple clock domains
有权
维护多个时钟域中FIFO内容的动态计数
- Patent Title: Maintaining dynamic count of FIFO contents in multiple clock domains
- Patent Title (中): 维护多个时钟域中FIFO内容的动态计数
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Application No.: US12058964Application Date: 2008-03-31
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Publication No.: US07646668B2Publication Date: 2010-01-12
- Inventor: John Udell , Richard Solomon , Eugene Saghi , Jeffrey K. Whitt
- Applicant: John Udell , Richard Solomon , Eugene Saghi , Jeffrey K. Whitt
- Applicant Address: US CA Milpitas
- Assignee: LSI Corporation
- Current Assignee: LSI Corporation
- Current Assignee Address: US CA Milpitas
- Agency: Cochran Freund & Young LLC
- Agent William W. Cochran
- Main IPC: G11C8/00
- IPC: G11C8/00

Abstract:
Disclosed is a system that generates a write count value for indicating whether data can be read from a FIFO and a system that generates a read count value for indicating whether data can be written to a FIFO. Each of these systems operates in two separate clock domains. In the system that generates a write count value, write strobes are stored in parallel in a register in a first clock domain. The plurality of synchronizers trigger on a rising edge of the write strobe that is stored in the parallel register and generate an increment pulse in a second clock domain. An up/down counter reads the increment pulse in parallel and increments the up/down counter in parallel. A decrement signal from a read strobe decrements the up/down counter. The output of the counter is fed to a register that provides a write counter value to handshake logic that indicates whether data can be read from a FIFO without underflowing the FIFO.
Public/Granted literature
- US20090244993A1 MAINTAINING DYNAMIC COUNT OF FIFO CONTENTS IN MULTIPLE CLOCK DOMAINS Public/Granted day:2009-10-01
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