Invention Grant
- Patent Title: Early data tag to allow data CRC bypass via a speculative memory data return protocol
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Application No.: US14098565Application Date: 2013-12-06
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Publication No.: US09231618B2Publication Date: 2016-01-05
- Inventor: Benjiman L. Goodman , Harrison M. McCreary , Stephen J. Powell , William J. Starke , Jeffrey A. Stuecheli
- Applicant: International Business Machines Corporation
- Applicant Address: US NY Armonk
- Assignee: International Business Machines Corporation
- Current Assignee: International Business Machines Corporation
- Current Assignee Address: US NY Armonk
- Agent Steven L. Bennett; Jack V. Musgrove
- Main IPC: G11C29/00
- IPC: G11C29/00 ; H03M13/09 ; G06F11/10

Abstract:
A bypass mechanism allows a memory controller to transmit requested data to an interconnect before the data's error code has been decoded, e.g., a cyclical redundancy check (CRC). The tag, tag CRC, data, and data CRC are pipelined from DRAM in four frames, each having multiple clock cycles. The tag includes a bypass bit indicating whether data transmission to the interconnect should begin before CRC decoding. After receiving the tag CRC, the controller decodes it and reserves a request machine which sends a transmit request signal to inform the interconnect that data is available. Once the transmit request is granted by the interconnect, the controller can immediately start sending the data, before decoding the data CRC. So long as no error is found, the controller completes transmission of the data to the interconnect, including providing an indication that the data as transmitted is error-free.
Public/Granted literature
- US20150149866A1 EARLY DATA TAG TO ALLOW DATA CRC BYPASS VIA A SPECULATIVE MEMORY DATA RETURN PROTOCOL Public/Granted day:2015-05-28
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