Memory module and method having improved signal routing topology
First Claim
1. A memory module, comprising:
- a plurality of memory devices;
a component having a plurality of input terminals and a plurality of output terminals; and
a symmetrical tree coupling each of several of the output terminals of the component to respective input terminals of the memory devices, the symmetrical tree comprising at least one branch, each branch including a pair of transmission lines coupled to each other at one end and to either a transmission line of another branch or one of the memory devices at another end, each of the transmission lines having a characteristic impedance, the transmission lines being arranged in a plurality of hierarchies with the transmission lines in the same hierarchy having substantially the same characteristic impedance.
1 Assignment
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Accused Products
Abstract
A registered memory module includes several memory devices coupled to a register through a plurality of transmission lines forming a symmetrical tree topology. The tree includes several branches each of which includes two transmission lines coupled only at its ends to either another transmission line or one of the memory devices. The branches are arranged in several layers of hierarchy, with the transmission lines in branches having the same hierarchy having the same length. Each transmission line preferably has a characteristic impedance that is half the characteristic impedance of any pair of downstream transmission lines to which it is coupled to provide impedance matching. A dedicated transmission line is used to couple an additional memory device, which may or may not be an error checking memory device, to the register.
358 Citations
24 Claims
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1. A memory module, comprising:
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a plurality of memory devices; a component having a plurality of input terminals and a plurality of output terminals; and a symmetrical tree coupling each of several of the output terminals of the component to respective input terminals of the memory devices, the symmetrical tree comprising at least one branch, each branch including a pair of transmission lines coupled to each other at one end and to either a transmission line of another branch or one of the memory devices at another end, each of the transmission lines having a characteristic impedance, the transmission lines being arranged in a plurality of hierarchies with the transmission lines in the same hierarchy having substantially the same characteristic impedance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A module, comprising:
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a plurality of first devices; a second device; and a symmetrical tree coupled to the second device, the symmetrical tree comprising a plurality of branches each of which comprises a pair of transmission lines coupled to each other and to another transmission line at one end and to either a transmission line of another branch or one of the first devices at another end, the transmission lines being arranged in a plurality of hierarchies with the transmission lines in the same hierarchy having substantially the same length. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A module, comprising:
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a plurality of first devices; a second device; and a symmetrical tree coupled to the second device, the symmetrical tree comprising at least one branch that comprises a pair of transmission lines coupled to each other and to another transmission line at one end and to either a transmission line of another branch or one of the first devices at another end, each of the transmission lines having a characteristic impedance, the transmission lines being arranged in a plurality of hierarchies with the transmission lines in the same hierarchy having substantially the same characteristic impedance. - View Dependent Claims (18, 19, 20, 21, 22)
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23. A module, comprising:
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a plurality of first devices; a second device; and a symmetrical tree coupled to the second device, the symmetrical tree comprising a plurality of branches each of which comprises a pair of transmission lines coupled to each other and to another transmission line at one end and to either a transmission line of another branch or one of the first devices at another end, the transmission lines being arranged in a plurality of hierarchies with both of transmission lines in the same hierarchy being configured so that a time period during which a signal may propagate through each of the transmission lines is substantially the same for both transmission lines. - View Dependent Claims (24)
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Specification