Same-channel memory module impedance matching method, memory unit and mainboard system

Abstract

The invention discloses a co-channel memory module impedance matching method, a memory unit and a mainboard system, and relates to the field of memory modules. The method comprises the following steps: changing the impedance of a wire in a memory module, so that the impedance of the memory module is doubled; two memory modules with the impedance doubled are arranged on the same channel, and the characteristic impedance of the system is matched. Complete matching with characteristic impedance of a system can be realized, signal reflection is not generated, and signal integrity and system stability are ensured.

Description

Technical Field

[0001] The present application relates to the field of memory modules, and in particular to a same-channel memory module impedance matching method, a memory unit and a motherboard system. Background Art

[0002] The application of memory modules may use the co-channel method. When two memory modules are used on the same channel, the impedance of the two memory modules will be connected in parallel, and the equivalent impedance will be half of the original impedance of the two memory modules. In this case, because the equivalent impedance does not match the characteristic impedance of the system, signal reflection will occur, thereby affecting the signal integrity and system stability. Summary of the invention

[0003] The purpose of the present application is to provide a same-channel memory module impedance matching method, a memory unit and a motherboard system, which can ensure signal integrity and system stability.

[0004] To achieve the above objectives, this application provides the following solutions.

[0005] In a first aspect, the present application provides a same-channel memory module impedance matching method, including: changing the impedance of the routing in the memory module to double the impedance of the memory module, specifically including: changing the impedance of the routing in the memory module by adjusting one or more of the line width of the routing in the memory module, the thickness of the board layer between the routing layer and the reference layer, and the dielectric constant of the printed circuit board material to double the impedance of the memory module; setting two memory modules with doubled impedance on the same channel to match the characteristic impedance of the system.

[0006] In a second aspect, the present application provides a memory unit, including: two memory modules on the same channel; each memory module uses the above-mentioned impedance matching method for memory modules on the same channel to double the impedance to match the characteristic impedance of the system.

[0007] In a third aspect, the present application provides a computer motherboard system, comprising: a CPU, at least one channel and at least one of the above-mentioned memory units; the number of channels is the same as the number of memory units; one end of all channels is connected to the CPU, and the other end of each channel is connected to two memory modules in a memory unit.

[0008] According to the specific embodiments provided in this application, this application has the following technical effects.

[0009] The present application provides a same-channel memory module impedance matching method, a memory unit and a motherboard system. By changing the impedance of the routing in the memory module, the impedance of the memory module is doubled. After two memory modules with doubled impedance are set on the same channel, the impedances of the two memory modules will be connected in parallel. The equivalent impedance of the two parallel memory modules is still equal to the characteristic impedance of the system, which is completely matched with the characteristic impedance of the system, and no signal reflection is generated, thereby ensuring signal integrity and system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 A schematic diagram of a flow chart of a same-channel memory module impedance matching method provided in one embodiment of the present application.

[0012] Figure 2 A schematic diagram of the structure of a microstrip line provided in another embodiment of the present application.

[0013] Figure 3 A schematic diagram of the structure of a strip line provided in another embodiment of the present application.

[0014] Figure 4 A schematic diagram of the impedance matching principle of a same-channel memory module provided by another embodiment of the present application.

[0015] Figure 5 A schematic diagram of the structure of a computer motherboard system when the number of memory units is two provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0018] In an exemplary embodiment, Figure 1As shown, a same-channel memory module impedance matching method is provided, including the following steps 101 to 102.

[0019] Step 101: changing the impedance of the wiring in the memory module to double the impedance of the memory module, which specifically includes: changing the impedance of the wiring in the memory module to double the impedance of the memory module by adjusting one or more of the line width of the wiring in the memory module, the thickness of the board layer between the wiring layer and the reference layer, and the dielectric constant of the printed circuit board material.

[0020] Step 102: Two memory modules with doubled impedance are arranged on the same channel to match the characteristic impedance of the system.

[0021] By implementing the above steps 101 to 102, the impedance of the memory module is doubled by changing the impedance of the wiring in the memory module. After two memory modules with doubled impedance are set on the same channel, the impedances of the two memory modules will be connected in parallel. The equivalent impedance of the two parallel memory modules is still equal to the characteristic impedance of the system, which is completely matched with the characteristic impedance of the system, and no signal reflection will be generated, thereby ensuring signal integrity and system stability.

[0022] The characteristic impedance of a device is defined according to the product standard. Different products are defined according to different standards. The memory module is defined according to the JEDEC (Joint Electron Device Engineering Council) standard. The characteristic impedance value is defined in the JEDEC standard.

[0023] The memory module includes a printed circuit board (PCB), a routing layer, and a reference layer. The printed circuit board is a physical platform that carries the routing layer and the reference layer. Routing refers to the conductive path that connects different electronic components on a printed circuit board. Generally, there are two types of routing on a printed circuit board: microstrip and stripline. The structure of a microstrip is as follows: Figure 2 As shown in Figure 1, the microstrip line consists of a routing layer and a reference layer. Figure 3 As shown, the stripline consists of one routing layer and two reference layers.

[0024] In one example, when the traces in the memory module are microstrip lines, the formula for changing the impedance of the traces in the memory module is as follows.

[0025] .

[0026] in, is the impedance of the memory module, is the line width of the trace, is the thickness of the board layer between the routing layer and the reference layer, is the dielectric constant of the printed circuit board material, is the thickness of the trace.

[0027] In another example, when the traces in the memory module are strip lines, the equation for changing the impedance of the traces in the memory module is as follows.

[0028] .

[0029] .

[0030] in, is the impedance of the memory module, is the line width of the trace, is the thickness of the board between the two reference layers, is the thickness of the board layer between the routing layer and the reference layer, is the dielectric constant of the printed circuit board material, is the thickness of the trace.

[0031] In another exemplary embodiment of the present application, Figure 4 As shown, the above step 102 may be specifically as follows: two memory modules with doubled impedance are set on the same channel, according to the formula , obtain the equivalent impedance of the two memory modules, and determine that the equivalent impedance of the two memory modules is equal to the characteristic impedance of the system, and the equivalent impedance completely matches the characteristic impedance of the system.

[0032] in, is the impedance of a memory module on the same channel, is the impedance of another memory module on the same channel, , is the characteristic impedance of the system, is the equivalent impedance of two memory modules on the same channel.

[0033] In another exemplary embodiment of the present application, the reflection coefficient is 0 after two memory modules with doubled impedance are arranged on the same channel. The formula derivation process is as follows.

[0034] .

[0035] in, is the reflection coefficient. As can be seen from the above formula, the reflection coefficient is equal to 0, no signal reflection is generated, and signal integrity and system stability are achieved.

[0036] Based on the same inventive concept, the embodiment of the present application also provides a memory unit that applies the above-mentioned same-channel memory module impedance matching method. The implementation scheme for solving the problem provided by the memory unit is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more memory unit embodiments provided below can refer to the above-mentioned limitations on the same-channel memory module impedance matching method, which will not be repeated here.

[0037] In an exemplary embodiment, a memory unit is provided, including: two memory modules in the same channel, wherein each memory module adopts the above-mentioned impedance matching method for memory modules in the same channel to increase impedance by one time, so as to match the characteristic impedance of the system.

[0038] Based on the same inventive concept, the embodiment of the present application also provides a computer motherboard system using the above-mentioned memory unit. The implementation scheme for solving the problem provided by the computer motherboard system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more computer motherboard system embodiments provided below can refer to the above-mentioned limitations on the same-channel memory module, which will not be repeated here.

[0039] In an exemplary embodiment, a computer motherboard system is provided, including: a CPU, at least one channel, and at least one of the above-mentioned memory units. The number of channels is the same as the number of memory units. One end of all channels is connected to the CPU, and the other end of each channel is connected to two memory modules in a memory unit.

[0040] As an optional implementation, the computer motherboard system further includes: a motherboard. A plurality of slots are provided on the motherboard; the number of the slots is equal to the total number of memory modules in all memory units. Each memory module in each memory unit is installed in a slot.

[0041] As another optional implementation, Figure 5 As shown, in current personal computer systems, the CPU generally has two channels (channel #1 and channel #2) connected to the memory modules. If a system with large memory capacity is required, two memory module slots will be installed in each channel, and each memory module slot will be inserted with a memory module. In this way, the maximum memory module capacity of the system is 4, and each channel is connected with two memory modules. When the number of memory units is two, four slots are opened on the motherboard; the four memory modules in the two memory units are installed in the four slots one by one; one end of the two channels is connected to the CPU, and the other end of one channel is connected to the two memory modules in one memory unit, and the other end of the other channel is connected to the two memory modules in another memory unit.

[0042] Figure 5In the example, memory module 1 and memory module 2 form a memory unit, and memory module 3 and memory module 4 form a memory unit. After the impedance value is doubled by adjusting the impedance of the memory module routing, memory module 1 and memory module 2 will be installed in the two memory module slots of the same channel of the computer system motherboard for use. Because the impedance of memory module 1 and memory module 2 has been doubled, when installed in the same channel, the impedance value of memory module 1 and memory module 2 after parallel connection will be equal to the characteristic impedance value of the system to achieve complete impedance matching. The same applies to memory module 3 and memory module 4.

[0043] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for impedance matching of a same-channel memory module, characterized in that: include: Changing the impedance of the wiring in the memory module so that the impedance of the memory module is doubled; specifically comprising: changing the impedance of the wiring in the memory module so that the impedance of the memory module is doubled by adjusting one or more of the line width of the wiring in the memory module, the thickness of the board layer between the wiring layer and the reference layer, and the dielectric constant of the printed circuit board material; Place two memory modules with double the impedance on the same channel to match the characteristic impedance of the system.

2. The same-channel memory module impedance matching method according to claim 1, characterized in that: When the traces in the memory module are microstrip lines, the formula for changing the impedance of the traces in the memory module is: ； in, is the impedance of the memory module, is the line width of the trace, is the thickness of the board layer between the routing layer and the reference layer, is the dielectric constant of the printed circuit board material, is the thickness of the trace.

3. The same channel memory module impedance matching method according to claim 1, characterized in that: When the traces in the memory module are strip lines, the formula for changing the impedance of the traces in the memory module is based on: ； ； in, is the impedance of the memory module, is the line width of the trace, is the thickness of the board between the two reference layers, is the thickness of the board layer between the routing layer and the reference layer, is the dielectric constant of the printed circuit board material, is the thickness of the trace.

4. The same-channel memory module impedance matching method according to claim 1, characterized in that: Two memory modules with double the impedance are placed on the same channel to match the characteristic impedance of the system, including: By setting two memory modules with doubled impedance on the same channel, according to the formula , obtain the equivalent impedance of the two memory modules, and determine that the equivalent impedance of the two memory modules is equal to the characteristic impedance of the system, and the equivalent impedance completely matches the characteristic impedance of the system; wherein, is the impedance of a memory module on the same channel, is the impedance of another memory module on the same channel, , is the characteristic impedance of the system, is the equivalent impedance of two memory modules on the same channel.

5. The same channel memory module impedance matching method according to claim 4, characterized in that: The reflection coefficient is 0 after placing two memory modules with double the impedance on the same channel.

6. A memory unit, characterized in that: The memory unit comprises: two memory modules in the same channel; Each memory module adopts the same-channel memory module impedance matching method described in any one of claims 1 to 5 to double the impedance and match the characteristic impedance of the system.

7. A computer motherboard system, characterized in that: The computer motherboard system comprises: a CPU, at least one channel and at least one memory unit as claimed in claim 6; The number of channels is the same as the number of memory cells; One end of all channels is connected to the CPU, and the other end of each channel is connected to two memory modules in a memory unit.

8. The computer motherboard system according to claim 7, characterized in that: The computer motherboard system further comprises: a motherboard; A plurality of slots are provided on the motherboard; the number of the slots is equal to the total number of memory modules in all memory units; Each memory module in each of the memory units is installed on a slot.

9. The computer motherboard system according to claim 8, characterized in that: When the number of memory units is two, four slots are provided on the motherboard; The four memory modules in the two memory units are installed in four slots in a one-to-one correspondence; One end of the two channels is connected to the CPU, the other end of one channel is connected to two memory modules in one memory unit, and the other end of the other channel is connected to two memory modules in another memory unit.

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