Method and apparatus for memory control
AssigneeAdvanced Micro Devices, Inc.
InventorsJames R. MAGRO, Shwetal A. PATEL
Life of this patent
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Abstract
A method is provided for issuing subcommands to a memory module using unassigned bits in a memory control protocol. A buffer component within the memory module receives the subcommands and modifies a state of the memory module accordingly. This allows, for example, selectively powering down individual ranks of the memory module (e.g., an LRDIMM memory module). Unassigned bits in a JEDEC-compliant ZQ calibration command set may be used for implementing such subcommands.
Claims20
A method for issuing a subcommand to a memory module configured to communicate in accordance with a memory communication protocol having a plurality of predefined commands, comprising:
- selecting, from the plurality of predefined commands, a predefined command that includes one or more undefined bits;
- encoding the subcommand within the selected predefined command using the undefined bits;
- and
- providing the selected predefined command for transmission to the memory module.
A method of controlling a memory module, comprising:
- selecting a set of one or more commands from a memory communication protocol configured to control the memory module, each of the set of one or more commands having at least one undefined bit;
- associating the at least one undefined bit with at least one subcommand;
- in response to receiving a command from the set of one or more commands, controlling the memory module based on the at least one subcommand of the received command.
An electronic device comprising:
- a memory module configured to communicate with a memory controller in accordance with a memory communication protocol having a plurality of predefined commands, at least one of the predefined commands including one or more unassigned bits;
- and
- wherein the memory module includes a buffer communicatively coupled to the memory controller, the buffer configured to receive a subcommand from the memory controller using the one or more of the unassigned bits, and to modify a state of the memory module in accordance with the subcommand.
Dependencies are inferred from the claim text.