Managing race conditions for DRAM self-refresh
AssigneeQUALCOMM Incorporated
InventorsSri Ananda Sai Jannabhatla, T S S Sai Prasad Bezawada, Subham Panda, Dinesh Nagjibhai Sudani, Radhakrishna Mugada, Trang Nguyen
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Abstract
Aspects of entry into self-refresh mode by a dynamic random-access memory (DRAM) may be managed using one or more polled registers. Indications of DRAM write activity by the DRAM or a DRAM client may be stored in the registers. The registers may be polled after entry into DRAM self-refresh mode is initiated. The DRAM's entry into self-refresh mode may not be allowed until the registers indicate absence of DRAM write activity.
Claims17
A system for managing dynamic random-access memory (DRAM) self-refresh, comprising:
- at least one register configured to store at least one indication of DRAM subsystem write activity associated with a DRAM client subsystem;
- and
- polling circuitry configured to detect initiation of DRAM self-refresh mode entry, to poll the at least one register in response to detection of initiation of DRAM self-refresh mode entry, and to prevent entry into DRAM self-refresh mode while the at least one register indicates DRAM subsystem write activity associated with the DRAM client subsystem,
- wherein the polling circuitry comprises a timer configured to begin timing a time interval when initiation of DRAM self-refresh mode entry is detected, and to prevent entry into DRAM self-refresh mode when the time interval expires before the at least one register indicates absence of DRAM subsystem write activity associated with the DRAM client subsystem.
A method for managing dynamic random-access memory (DRAM) self-refresh, comprising:
- storing, by at least one register, at least one indication of DRAM subsystem write activity associated with a DRAM client subsystem;
- and
- detecting, by polling circuitry, initiation of DRAM self-refresh mode entry;
- polling, by the polling circuitry, the at least one register in response to detection of initiation of DRAM self-refresh mode entry;
- preventing entry into DRAM self-refresh mode while the at least one register indicates DRAM subsystem write activity associated with the DRAM client subsystem;
- timing a time interval beginning when initiation of DRAM self-refresh mode entry is detected;
- and
- preventing entry into DRAM self-refresh mode when the time interval expires before the at least one register indicates absence of DRAM subsystem write activity associated with the DRAM client subsystem.
A system for managing dynamic random-access memory (DRAM) self-refresh, comprising:
- means for storing at least one indication of DRAM subsystem write activity associated with a DRAM client subsystem;
- and
- means for detecting initiation of DRAM self-refresh mode entry;
- means for polling the means for storing in response to detection of initiation of DRAM self-refresh mode entry;
- means for preventing entry into DRAM self-refresh mode while the means for storing indicates DRAM subsystem write activity associated with the DRAM client subsystem;
- means for timing a time interval beginning when initiation of DRAM self-refresh mode entry is detected;
- and
- the means for preventing entry into DRAM self-refresh mode comprises means for preventing entry into DRAM self-refresh mode when the time interval expires before the means for storing the indication indicates absence of DRAM subsystem write activity associated with the DRAM client subsystem.
Dependencies are inferred from the claim text.