Dynamic Refresh Rate Control
AssigneeApple Inc.
InventorsLiang Deng, Norman J. Rohrer, Yizhang Yang, Arpit Mittal
Life of this patent
Estimating the term…
Abstract
In an embodiment, a memory controller in an integrated circuit may generate refreshes for one or more DRAMs coupled to the integrated circuit according to a refresh rate. The integrated circuit may include one or more temperature sensors. A rate of change of the temperature may be determined from the temperature sensors. If the rate is greater than a threshold, the memory controller may generate refreshes according to a refresh rate specified by the DRAMs. If the rate is less than the threshold, the memory controller may generate refreshes at a reduced refresh rate.
Claims20
A system comprising:
- a dynamic random access memory (DRAM) including a first temperature sensor, wherein the DRAM is configured to generate a first refresh rate responsive to a temperature sensed by the first temperature sensor;
- an integrated circuit coupled to the DRAM, wherein the integrated circuit comprises:
- a memory controller configured to control a second refresh rate at which the memory controller refreshes the DRAM;
- and
- at least one second temperature sensor, wherein a temperature change rate is determined based on successive temperature measurements from the second temperature sensor and further based on an amount of time between the successive temperature measurements;
- wherein the memory controller is configured to select the second refresh rate as the first refresh rate based on the temperature change rate exceeding a threshold level, and wherein the memory controller is configured to select the second refresh rate as a lower rate than the first refresh rate based on the temperature change rate not exceeding the threshold level.
An integrated circuit comprising:
- a plurality of temperature sensors;
- and
- a memory controller configured to refresh at least one dynamic random access memory (DRAM) at a refresh rate, wherein refresh rate is based on a temperature change rate determined from the plurality of temperature sensors, wherein the temperature change rate is based on a plurality of consecutive temperatures sensed by a given temperature sensor of the plurality of temperature sensors, wherein the temperatures sensed by the given temperature sensor are greater than the temperatures sensed by other ones of the plurality of temperature sensors.
A system comprising:
- a dynamic random access memory (DRAM) including a first temperature sensor, wherein the DRAM is configured to generate a first refresh rate responsive to a temperature sensed by the first temperature sensor, wherein the temperature is mapped to the first refresh rate at a first granularity;
- an integrated circuit coupled to the DRAM, wherein the integrated circuit comprises:
- at least one second temperature sensor, wherein a temperature change rate is determined based on temperatures sensed by the second temperature sensor, and wherein the temperatures sensed by the at least one second temperature sensor are mapped to a second refresh rate at a second granularity that is finer than the first granularity;
- and
- a memory controller configured to refresh the DRAM at a selected one of the first refresh rate and the second refresh rate based on the temperature change rate.
Dependencies are inferred from the claim text.