Method and apparatus for signaling between devices of a memory system
First Claim
1. A memory system comprising:
- a memory controller;
a plurality of memory components;
a control bus coupled to the memory controller and coupled to each memory component of the plurality of memory components at a different point along its length such that respective, different times are required for control information to propagate on the control bus from the memory controller to each memory component of the plurality of memory components;
a plurality of dedicated differential data signaling paths coupled to the memory controller, each dedicated differential data signaling path of the plurality of dedicated differential data signaling paths coupled respectively to a memory component of the plurality of memory components; and
wherein the memory controller includes circuitry to transmit respective differential data signals to the plurality of memory components via the plurality of dedicated differential data signaling paths after delaying by respective, different time intervals to at least account for the respective, different times required for the control information to propagate on the control bus from the memory controller to each respective memory component of the plurality of memory components.
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Accused Products
Abstract
A method and apparatus for signaling between devices of a memory system is provided. In accordance with an embodiment of the invention, one or more of several capabilities are implemented to provide heretofore unattainable levels of important system metrics, for example, high performance and/or low cost. These capabilities relate to timing adjustment capabilities, bit time adjustment capabilities, cycle time selection, use of differential and/or non-differential signaling for bus signals and/or clock signals, use of termination structures on a bus, including integrated termination structures, and active control circuitry to allow adjustment to different characteristic bus impedances and power-state control, including a calibration process to optimize the termination value, use of slew rate control circuitry and transfer characteristic control circuitry in the predriver and driver of transmitter blocks to allow adjustment to different characteristic bus impedances and to allow adjustment for other bus properties, including a calibration process to optimize the such circuitry, and/or provision of a memory component designed to prefetch (preaccess) words that are wider than the width of the data bus so that the memory access bandwidth approximately matches the transfer bandwidth, and memory component able to adjust the size of the prefetch (preaccess) word to accommodate connection to data buses of different width.
334 Citations
35 Claims
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1. A memory system comprising:
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a memory controller; a plurality of memory components; a control bus coupled to the memory controller and coupled to each memory component of the plurality of memory components at a different point along its length such that respective, different times are required for control information to propagate on the control bus from the memory controller to each memory component of the plurality of memory components; a plurality of dedicated differential data signaling paths coupled to the memory controller, each dedicated differential data signaling path of the plurality of dedicated differential data signaling paths coupled respectively to a memory component of the plurality of memory components; and wherein the memory controller includes circuitry to transmit respective differential data signals to the plurality of memory components via the plurality of dedicated differential data signaling paths after delaying by respective, different time intervals to at least account for the respective, different times required for the control information to propagate on the control bus from the memory controller to each respective memory component of the plurality of memory components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A memory controller comprising:
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control transmit circuitry to transmit control information to a plurality of memory components via a control bus, the control bus being coupled to each memory component of the plurality of memory components at a different point along its length such that respective times required for the control information to propagate from the memory controller to each memory component of the plurality of memory components are different; dedicated differential data transmit circuitry to transmit differential data signals to the plurality of memory components via respective differential data signaling paths; and timing circuitry to delay transmission of the respective differential data signals on each of the differential data signaling paths by a respective time interval that is based, at least in part, on the time required for the control information to propagate on the control bus from the memory controller to each respective memory component of the plurality of memory components. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A method of controlling memory components in a system that includes at least a first memory component and a second memory component, the method comprising:
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transmitting control information to the first and second memory components via a control bus, wherein the control information propagates past the first memory component and the second memory component in sequence, and wherein a first propagation time required for the control information to propagate on the control bus to the first memory component is different from a second propagation time required for the control information to propagate on the control bus to the second memory component; transmitting a first differential data signal to the first memory component via a first dedicated differential data signaling path after delaying for a first time interval, wherein the first time interval is based at least in part on the first propagation time; and transmitting a second differential data signal to the second memory component via a second dedicated differential data signaling path after delaying for a second time interval, wherein the second time interval is based at least in part on the second propagation time. - View Dependent Claims (31, 32, 33, 34)
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35. A memory controller for controlling memory components in a system that includes at least a first memory component and a second memory component, the memory controller comprising:
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means for transmitting control information to the first and second memory components via a control bus, wherein the control information propagates past the first memory component and the second memory component in sequence, and wherein a first propagation time required for the control information to propagate on the control bus to the first memory component is different from a second propagation time required for the control signal to propagate on the control bus to the second memory component; means for transmitting a first differential data signal to the first memory component via a first dedicated differential data signaling path after delaying for a first time interval, wherein the first time interval is based at least in part on the first propagation time; and means for transmitting a second differential data signal to the second memory component via a second dedicated differential data signaling path after delaying for a second time interval, wherein the second time interval is based at least in part on the second propagation time.
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Specification