Serial presence detect driven memory clock control
First Claim
1. A method of selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said method comprising:
- counting the number of said memory modules;
generating multiple clock frequencies to provide selectable operating speeds of said memory module interface; and
selecting one of said operating speeds of said memory module interface in accordance with said counting.
1 Assignment
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Accused Products
Abstract
In a computer system, the operating speed of the memory module interface is selected in accordance with information stored in serial presence detect EEPROMs, such as the number of memory modules coupled to a memory controller of the computer system. The memory controller has clocks of various frequencies available to it to drive the memory modules. The most optimal clock is preferably chosen based on at least the number or other characteristics, such as speed, of memory modules. This permits the memory modules to be driven with a higher speed clock when, for example, there are fewer than the maximum number of memory modules present in the system.
42 Citations
53 Claims
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1. A method of selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said method comprising:
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counting the number of said memory modules;
generating multiple clock frequencies to provide selectable operating speeds of said memory module interface; and
selecting one of said operating speeds of said memory module interface in accordance with said counting. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said method comprising:
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counting the number of said memory modules;
obtaining information from said serial presence detect memory that includes at least one characteristic of said memory module; and
selecting said operating speed of said memory module interface in accordance with at least one of said counting and said obtaining information. - View Dependent Claims (10)
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11. A method of selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said method comprising:
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counting the number of said memory modules;
obtaining information from said serial presence detect memory that includes at least the number of components in each said memory module; and
selecting said operating speed of said memory module interface in accordance with at least one of said counting and said obtaining information. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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12. A method of selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said method comprising:
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counting the number of said memory modules;
obtaining information from said serial presence detect memory that includes at least a speed grade of said memory module; and
selecting said operating speed of said memory module interface in accordance with at least one of said counting and said obtaining information.
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13. A computer system comprising:
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a central processing unit;
a memory controller including a memory module interface; and
at least one memory module including a serial presence detect memory;
wherein said memory controller;
generates multiple clock frequencies;
accesses said serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory; and
selects one of said clock frequencies for driving said memory module interface based on at least a final tally of the number of said memory modules.
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21. A computer system comprising:
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a central processing unit;
a memory controller including a memory module interface;
at least one memory module including a serial presence detect memory;
wherein said memory controller;
accesses said serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least one characteristic of said memory module; and
provides a memory module interface at a clock rate based on at least one of a final tally of the number of said memory modules and said obtained information. - View Dependent Claims (22, 27, 28)
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23. A computer system comprising:
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a central processing unit;
a memory controller including a memory module interface;
at least one memory module including a serial presence detect memory;
wherein said memory controller;
accesses said serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least the number of components in each memory module; and
provides a memory module interface at a clock rate based on at least one of a final tally of the number of said memory modules and said obtained information.
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24. A computer system comprising:
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a central processing unit;
a memory controller including a memory module interface;
at least one memory module including a serial presence detect memory;
wherein said memory controller;
accesses said serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least a speed grade of said memory modules or their components; and
provides a memory module interface at a clock rate based on at least one of a final tally of the number of said memory modules and said obtained information.
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25. A computer system comprising:
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a central processing unit;
at least one memory module including a serial presence detect memory; and
memory controller means including memory module interface means;
wherein said memory controller means;
generates multiple clock frequencies;
accesses serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory; and
selects one of said clock frequencies for driving said memory module interface means at a clock rate based on at least a final tally of the number of said memory modules.
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26. A computer system comprising:
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a central processing unit;
at least one memory module including a serial presence detect memory; and
memory controller means including memory module interface means;
wherein said memory controller means;
accesses serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least one characteristic of said memory module; and
provides a memory module interface means at a clock rate based on at least one of a final tally of the number of said memory modules and said obtained information.
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29. A computer system comprising:
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a central processing unit;
at least one memory module including a serial presence detect memory; and
memory controller means including memory module interface means;
wherein said memory controller means;
accesses serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least the number of components in each memory module means; and
provides a memory module interface means at a clock rate based on at least one of a final tally of the number of said memory modules and said obtained information.
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30. A computer system comprising:
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a central processing unit;
at least one memory module including a serial presence detect memory; and
memory controller means including memory module interface means;
wherein said memory controller means;
accesses serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least a speed grade of said memory module or its components; and
provides a memory module interface means at a clock rate based on at least one of a final tally of the number of said memory modules and said obtained information.
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31. A memory controller comprising a memory module interface to at least one memory module, said memory module including serial presence detect memory;
- wherein said memory controller;
accesses serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory; and
provides a memory module interface at a clock rate based on at least at least a final tally of the number of said memory modules. - View Dependent Claims (32, 33, 34, 35, 36, 37, 39)
- wherein said memory controller;
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38. A memory controller comprising a memory module interface to at least one memory module, said memory module including serial presence detect memory;
- wherein said memory controller;
generates multiple clock frequencies;
accesses serial presence detect memory;
keeps a running tally of the number of said memory modules based on said accesses to said serial presence detect memory;
obtains information from said serial presence detect memory that includes at least one characteristic of said memory module; and
selects one of said clock frequencies for driving said memory module interface based on at least one of a final tally of the number of said memory modules and said obtained information.
- wherein said memory controller;
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40. A memory controller comprising a memory module interface to at least one memory module, said memory module including serial presence detect memory;
- wherein said memory controller;
accesses serial presence detect memory;
obtains information from said serial presence detect memory that includes at least the number of components in said memory module; and
provides a memory module interface at a clock rate based on said obtained information.
- wherein said memory controller;
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41. A memory controller comprising a memory module interface to at least one memory module, said memory module including serial presence detect memory;
- wherein said memory controller;
accesses serial presence detect memory;
generates multiple clock frequencies;
obtains information from said serial presence detect memory; and
selects one of said clock frequencies for driving said memory module interface based on said obtained information. - View Dependent Claims (42)
- wherein said memory controller;
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43. Apparatus for selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said apparatus comprising:
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means for counting the number of said memory modules;
means for generating multiple clock frequencies to provide selectable operating speeds of said memory interface; and
means for selecting one of said multiple clock frequencies to provide an operating speed in accordance with said counted memory modules. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50)
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51. Apparatus for selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said apparatus comprising:
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means for counting the number of said memory modules;
means for obtaining information from said serial presence detect memory that includes at least one characteristic of said memory module; and
means for selecting said operating speed of said memory module interface in accordance with at least one of said means for counting and obtaining information.
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52. Apparatus for selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, a memory controller, and at least one memory module comprising a serial presence detect memory, said apparatus comprising:
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means for counting the number of said memory modules;
means for obtaining information from said serial presence detect memory that includes at least the number of components in each said memory module; and
means for selecting said operating speed of said memory module interface in accordance with at least one of said means for counting and obtaining information.
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53. Apparatus for selecting an operating speed of a memory module interface in a computer system, said system comprising a central processing unit, and a memory controller, and at least one memory module comprising a serial presence detect memory, said apparatus comprising:
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means for counting the number of said memory modules;
means for obtaining information from said serial presence detect memory that includes at least a speed grade of said memory module; and
means for selecting said operating speed of said memory module interface in accordance with at least one of said means for counting and obtaining information.
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Specification