Dynamic data strobe detection
AssigneeApple Inc.
InventorsHao Chen, Rakesh L. Notani, Sukalpa Biswas
Life of this patent
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Abstract
Techniques are disclosed relating to determining when a data strobe signal is valid for capturing data. In one embodiment, an apparatus is disclosed that includes a memory interface circuit configured to determine an initial time value for capturing data from a memory based on a data strobe signal. In some embodiments, the memory interface circuit may determine this initial time value by reading a known value from memory. In one embodiment, the memory interface circuit further configured to determine an adjusted time value for capturing the data, where the memory interface circuit is configured to determine the adjusted time value by using the initial time value to sample the data strobe signal.
Claims17
An apparatus, comprising:
- a memory interface circuit configured to determine an initial time value for capturing data from a memory based on a data strobe signal, wherein the memory interface circuit is configured to determine the initial time value by:
- issuing a single request for performance of a read operation in which a known value is to be retrieved from the memory;
- performing a plurality of data captures at different respective time offsets during the read operation;
- comparing the plurality of data captures with a copy of the known value;
- and
- based on the comparing, selecting one of the different respective time offsets as the determined initial time value;
- and
- wherein the memory interface circuit is configured to determine an adjusted time value for capturing the data, wherein the memory interface circuit is configured to determine the adjusted time value by using the initial time value to sample the data strobe signal, and the memory interface circuit is further configured to determine the adjusted time value without performance of a read operation in which a known value is retrieved from the memory.
An apparatus, comprising:
- a memory interface circuit, wherein the memory interface circuit is configured to:
- detect a time between issuing a data request to memory and receiving a corresponding data strobe signal from the memory;
- use the detected time to validly capture data received from the memory;
- redetect the time by periodically sampling the data strobe signal, wherein the memory interface circuit is configured to redetect the time by:
- maintaining a counter indicating when a last redetection of the time was performed;
- and
- performing a redetection upon expiration of the counter.
A method, comprising:
- a memory interface circuit detecting a time between issuing a data request to a memory and receiving a corresponding data strobe signal from the memory;
- the memory interface circuit using the detected time to validly capture data from the memory;
- and
- the memory interface circuit redetecting the time by periodically sampling the data strobe signal, wherein the redetecting the time includes:
- maintaining a counter indicating when a last redetection of the time was performed;
- and
- performing a redetection upon expiration of the counter.
Dependencies are inferred from the claim text.