Method and system of adjusting DRAM refresh interval

{
  "publication_number": "US2005036380A1",
  "country": "US",
  "kind": "A1",
  "title": "Method and system of adjusting DRAM refresh interval",
  "abstract": "A method of refreshing a DRAM chip. A working temperature is detected for the DRAM, and a corresponding refresh interval is decided accordingly. A refresh timing clock is generated with the corresponding refresh interval, and the DRAM is refreshed. The refresh interval decreases with increased working temperature, and increased with working temperature decrease.",
  "claims": [
    "1. A method of refreshing a DRAM chip, comprising: detecting a working temperature for the DRAM; setting a corresponding refresh interval according to the working temperature; and generating a refresh timing clock with the corresponding refresh interval, and executing a refresh process for the DRAM.",
    "2. The method of refreshing a DRAM chip in claim 1, wherein, when the working temperature is within a first temperature range, the corresponding refresh interval is determined as a first refresh interval, and when the working temperature is within a second temperature range, the corresponding refresh interval is determined as a second refresh interval.",
    "3. The method of refreshing a DRAM chip in claim 2, wherein the corresponding refresh interval is determined according to a comparison table.",
    "4. The method of refreshing a DRAM chip in claim 2, wherein the first temperature range is higher than the second temperature range and the first refresh interval is shorter than the second refresh interval.",
    "5. The method of refreshing a DRAM chip in claim 1, wherein the working temperature is detected by an energy gap voltage reference source, to output a reference voltage.",
    "6. The method of refreshing a DRAM chip in claim 5, wherein the reference voltage is used to control a frequency of an oscillator, thereby providing the corresponding refresh interval.",
    "7. A DRAM refresh system, embedded in a DRAM chip, comprising: a temperature sensor detecting a working temperature for the DRAM, to generate a corresponding temperature signal; a refresh interval adjustment module deciding a corresponding refresh interval according to the temperature signal; a clock generator generating a refresh timing clock with the corresponding refresh interval; and a refresh module executing a refresh for the DRAM according to the refresh timing clock.",
    "8. The DRAM refresh system of claim 7, wherein the temperature sensor is an energy gap voltage reference source.",
    "9. The DRAM refresh system of claim 7, wherein the refresh interval adjustment module is an oscillator."
  ],
  "cpc": [
    "G11C 11/40626",
    "G11C 11/406",
    "G11C 2211/4061"
  ],
  "filing_date": "2003-08-14",
  "publication_date": "2005-02-17",
  "priority_date": "2003-08-14",
  "application_number": "US-64031303-A",
  "family_id": "34136067",
  "citations": [
    "US5652729A",
    "US6438057B1",
    "US6728156B2"
  ]
}