Refreshing method for dynamic random access memory

Abstract

The invention provides a refreshing method for a DRAM (dynamic random access memory). The method comprises the steps of setting an initial value of a counter, wherein the count of the counter is decreased every one decreasing period; judging whether the lines of the DRAM are accessed, if yes, entering the next refreshing period by setting the value of the counter as the initial value, and if not, when the value of the counter is decreased to the minimum count value, searching whether an access operation for the line to be refreshed exists in an access storage order queue, and if the access for the line to be refreshed exists in the access storage order queue, using a scheduler to execute in priority and setting the value of the counter as the initial value to enter the next refreshing period. Three priority scheduling algorithms of prior line targeting, the prior access order of the line to be refreshed and the first coming and first serving are adopted by the method to perform the DRAM control operation, and partial refreshing operation is replaced by prior scheduling the access to the line to be refreshed, so the refreshing times are reduced, the power consumption of the DRAM is reduced, and system performance is enhanced.

Description

technical field [0001] The present invention relates to a memory refresh method, in particular, to a refresh method of dynamic random access memory. Background technique [0002] Dynamic Random Access Memory (DRAM) has low unit storage cost and high integration density, and is widely used in modern computer systems. DRAM is a volatile memory device. In order to keep data from being lost, a refresh operation is required. The JEDEC standard stipulates that the refresh cycle of DRAM cells is 64ms (32ms at high temperature), and all DRAM rows must be refreshed within the refresh cycle. If the memory cells are not refreshed, the stored information is lost. [0003] At present, the scheduling algorithm usually used by the DRAM memory controller is FR-FCFS (First-Ready First-Come-First-Serve, row hit first-first come first serve), which determines the next memory access request to be responded to. The main features of the algorithm are row hit first and earliest request first. T...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a kind of refreshing method of DRAM in view of the shortcoming of prior art, to solve the problems of frequent refresh times, memory access delay and large power consumption in the memory refreshing method of prior art, reduce power consumption and improve performance

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