A DDR bus interconnection design method based on a pin header connector

Abstract

The application discloses a DDR bus interconnection design method based on a velcro connector, which splits a processor with high design complexity and a DDR interconnection circuit into a DDR memory card which is interconnected with the processor through a velcro connector, so as to realize decoupling of the complex circuit and the simple circuit. After decoupling, the DDR part circuit is complex but does not need to be repeatedly designed, and the processor circuit needs to be redesigned for each project but the complexity is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of DDR circuit in avionics circuit, and relates to a DDR bus interconnection design method based on a velcro connector. BACKGROUND

[0002] Avionics has the engineering characteristics of high reliability requirement, high density and high iteration cost. As the most core circuit in the processor minimum system, DDR uses high-speed parallel bus with high design difficulty. With the continuous improvement of performance requirements, the selection of DDR is continuously upgraded, the signal rate is higher and higher, the layout and wiring difficulty is greater and greater, the signal integrity design and timing control requirement is more and more strict, and the design of DDR has become the difficulty of the whole circuit board design. Any design mistake may cause DDR access failure or rate reduction. At present, the mainstream DDR used in aviation field has been upgraded from DDR3 to DDR4, and the signal rate has been upgraded from 1Gbps to 2Gbps. In order to meet the performance requirements of the product, the number of DDR4 particles in each channel is usually 4, 5 or 9. The address line using flyby topology is prone to signal integrity problems after mounting multiple DDR4 particles. The layout and wiring of DDR4 have the characteristics of strong independence, which is only related to the processor. In the traditional circuit board module, the DDR circuit is directly laid beside the processor. The DDR layout is constrained by the size and shape of the circuit board and has to be repeatedly adjusted and redesigned. The soldering yield of high-density circuit is lower than that of ordinary circuit board. After assembly, the stress is more complex than that of ordinary circuit board. The device detachment rate caused by the deformation of printed board is higher. When repairing the detached device, it is more likely to cause the detachment of surrounding devices due to the small distance between devices. The probability of soldering problem of DDR4 is higher due to the large number of devices and large area occupied. It is difficult to locate the soldering problem chip when the soldering problem occurs.

[0003] Based on the above design difficulties, the present application provides a DDR bus interconnection design method based on a velcro connector. The method separates the DDR memory card and forms a DDR memory card which is easy to disassemble. The interconnection between the DDR memory card and the processor is realized through the velcro connector with low loss, high reliability and no soldering. The DDR part of the complex circuit can be decoupled from the whole circuit, which brings many benefits in reliability, efficiency, cost and other aspects, and has great value and application prospect. SUMMARY

[0004] The application aims to provide a DDR bus interconnection design method based on a pogo pin connector, realize interconnection between a DDR memory card and a processor through the pogo pin connector, split out a high-design-complexity DDR part circuit to form an independent DDR memory card, decouple the DDR memory card from the processor, and reduce wiring difficulty of the processor.

[0005] The application aims to provide a DDR bus interconnection design method based on a pogo pin connector, realize interconnection between a DDR memory card and a processor through the pogo pin connector, split out a high-design-complexity DDR part circuit to form an independent DDR memory card, decouple the DDR memory card from the processor, and reduce wiring difficulty of the processor.

[0006] The application aims to provide a DDR bus interconnection design method based on a pogo pin connector, realize interconnection between a DDR memory card and a processor through the pogo pin connector, split out a high-design-complexity DDR part circuit to form an independent DDR memory card, decouple the DDR memory card from the processor, and reduce wiring difficulty of the processor.

[0007] The pin impedance of the pogo pin connector is controlled to be 45±5Ω for single-end signals and 75±8Ω for differential signals;

[0008] The impedance of the wiring directly interconnected with the pogo pin connector in the processor-containing functional module is consistent with the impedance of the pogo pin connector;

[0009] The pogo pin connector is filled with sufficient copper wires to ensure uniform pins;

[0010] The pin length of the pogo pin connector is set to 5mm, the compression amount is 1mm, the shell height of the pogo pin connector is 4±0.03mm, and the DDR memory card is installed on the back of the processor;

[0011] The pin spacing of the pogo pin connector is set to 1mm;

[0012] The pogo pin connector is set to be double-sided floating, and the welding process is omitted.

[0013] Further, positioning pins are arranged on the pogo pin connector, and positioning holes are arranged at corresponding positions of the processor-containing functional module and the DDR memory card.

[0014] Further, one mounting hole is added to each side and the middle of the pogo pin connector shell, and mounting holes are also added to corresponding positions of the DDR memory card and the processor-containing functional module, and the DDR memory card, the pogo pin connector and the processor-containing functional module are fixed through screws.

[0015] Further, the hole diameter of the mounting hole on the pogo pin connector shell is 2.3±0.2mm.

[0016] Further, two mounting holes are arranged on the DDR memory card and the functional module with the processor on the opposite side of the velcro connector, and a stud with a height of 4 mm is used to assemble between the DDR memory card and the functional module with the processor.

[0017] Further, according to whether there is a deformation, a pressing strip is arranged on the outside of the DDR memory card and the functional module with the processor.

[0018] Further, the pressing strip is made of metal, and an insulating pad is arranged between the pressing strip and the functional module with the processor and between the pressing strip and the DDR memory card.

[0019] The application has the following beneficial effects:

[0020] The application provides a DDR bus interconnection design method based on a velcro connector, which splits a processor with high design complexity and a DDR interconnection circuit into a DDR memory card connected to the processor through a velcro connector, realizes decoupling of complex circuits and simple circuits, and after decoupling, the DDR part circuit is complex but does not need to be repeatedly designed, and the processor circuit needs to be redesigned for each project but the complexity is greatly reduced. The method has remarkable benefits in improving the design success rate, reliability, welding success rate, repair success rate, and fault positioning efficiency of a product, and can shorten the project development cycle and save project cost. The method has an irreplaceable value and application prospect in further improving the reliability and development cycle of aviation electronic products in China.

[0021] The welding-free advantage of the velcro connector can bring the following benefits: reducing the welding density of a circuit board, indirectly improving the welding yield; when repairing, the DDR part circuit can be independently disassembled, reducing the influence domain of local heating of devices during repair; when the capacity or model of the DDR is changed, the DDR memory card can be directly changed, reducing the cost and cycle of re-development; the velcro connector design can meet the requirements of signal integrity of the DDR high-speed parallel bus, and can also reduce the occupied area on the circuit board, which is more conducive to adapting to diversified size requirements, greatly reduces the design difficulty of the circuit board and saves a large amount of circuit board wiring resources. The method has remarkable benefits in improving the design success rate, reliability, welding success rate, repair success rate, and fault positioning efficiency of a product, and can shorten the project development cycle and save project cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is an assembly schematic diagram of the velcro connector interconnection in the application;

[0023] Figure 2 is an effect schematic diagram of the DDR bus interconnection design method based on the velcro connector of the application.

[0024] Label explanation:

[0025] 1 - the connector, 2 - the functional module of the processor, 3 - the DDR memory card, 4 - the compression strip, 5 - the insulating pad, 6 - the compression strip, 7 - the screw, 8 - the screw, 9 - the stud, 10 - the nut DETAILED DESCRIPTION

[0026] The application will be further described in detail below with reference to the drawings and examples.

[0027] Referring to Figure 1 The design method of the DDR bus interconnection based on the connector shown in the embodiment relates to one connecting component (the connector 1), two functional components (the functional module 2 containing the processor and the DDR memory card 3), eleven reinforcing components (one compression strip 4 containing a threaded hole, one compression strip 6 containing a through hole, three screws 7, two screws 8, two studs, and two nuts), and two insulating components (the insulating pad 5), and the processor and the DDR interconnection circuit with high design complexity are split into a DDR memory card and a functional module containing a processor interconnected through the connector.

[0028] When designing, the following considerations are made:

[0029] The pin impedance of the connector 1 is controlled to be 45±5Ω for single-ended signals and 75±8Ω for differential signals.

[0030] The impedance of the wire directly interconnected with the connector 1 in the functional module 2 containing the processor should be consistent with the impedance control of the connector 1.

[0031] The connector 1 is filled with sufficient copper wires to ensure uniform pins and reduce the insertion loss introduced by the pins. The single-ended insertion loss of the connector is controlled to be within 0.1 dB at 3 GHz, and the return loss is controlled to be more than 20 dB, so the influence on the signal can be ignored.

[0032] The pin length of the connector 1 is set to 5 mm, the compression amount is 1 mm, the height of the shell of the connector is 4±0.03 mm, the DDR memory card 3 can be installed on the back of the processor, and the welding height requirement of the decoupling capacitor on the back of the processor and the DDR memory card device is met.

[0033] The pin pitch of the connector 1 is set to 1 mm. This pitch meets the requirements of the connector itself on the size of the compression disc and the wire pitch, and is easy to control the impedance of the connector 1.

[0034] The positioning pin is arranged on the wool button connector 1, the corresponding position on the functional module with the processor and the DDR memory card is provided with a positioning hole, and the precise positioning is realized through the design of the positioning pin and the positioning hole, so that the signal interconnection and intercommunication are achieved.

[0035] The wool button connector 1 is arranged to be double-side floating, the welding process is omitted, and the contact quality is improved.

[0036] One mounting hole is arranged on each of the two sides and the middle of the shell of the wool button connector 1, so that the wool button connector is fixed and the deformation of the printed board after being compressed by the wool button connector is reduced, and a small hole with a diameter of 2.3±0.2 mm is used to reduce the area occupied.

[0037] Two mounting holes are arranged on the opposite side of the wool button connector 1 on the DDR memory card 3 and the functional module 2, a stud with a height of 4 mm is arranged between the functional module 2 and the DDR memory card 3, and the stud supports the functional module 2 and the DDR memory card 3 together with the wool button connector 1.

[0038] The pressing strips 4 and 6 are arranged on the outer sides of the functional module 2 and the DDR memory card 3 according to whether there is deformation, and the strength is supported. In order to better reduce the deformation, the pressing strips 4 and 6 are made of metal, and in order to solve the short circuit risk caused by the metal pressing strip, the insulating pad 5 is arranged between the pressing strip 6 and the functional module 2 and between the pressing strip 4 and the DDR memory card.

[0039] When interconnected, the functional module 2 with the processor is interconnected with the wool button connector 1, whether the pressing strip 6 with the through hole is needed to offset the deformation according to the deformation amount of the functional module 2 with the processor, the insulating pad 5 is arranged between the functional module 2 with the processor and the pressing strip 6 with the through hole to avoid short circuit. When the thickness of the functional module 2 is not less than 2.5 mm, there is a possibility that the rigidity of the functional module 2 itself is sufficient to offset the deformation, and at this time, the pressing strip 6 with the through hole can not be used.

[0040] The DDR memory card 3 has low circuit complexity, and the rigidity of the printed board is not enough, so the pressing strip 4 with the threaded hole is needed to offset the deformation, and the insulating pad 5 is arranged between the DDR memory card 3 and the pressing strip 4 with the threaded hole to avoid short circuit.

[0041] The screw 7 penetrates the pressing strip 6 with the through hole, the insulating pad 5, the functional module 2, the wool button connector 1, the DDR memory card 3, the insulating pad 5, and finally connects with the thread on the pressing strip 4 with the threaded hole. The number of screws 7 is set to 3 to ensure reliable connection. According to the actual operation and convenience requirements, the screw 7 and the pressing strip 6 with the through hole can be transposed with the pressing strip 4 with the threaded hole, and the purpose of reliable connection can be achieved.

[0042] Screw 8 penetrates functional module 2, stud 9, DDR memory card 3 and is connected with the thread on nut 10, the number of interconnections is not less than 2, which supports the interconnection between functional module 2 and DDR memory card 3. According to the actual operation, screw 8 and nut 10 can also be transposed to achieve reliable connection.

[0043] Screw 7, screw 8 and nut 10 can also be supplemented with flat pads and elastic pads on the contact surface with other components to further improve the reliability of reinforcement.

[0044] Referring to Figure 2 The assembled effect diagram is shown, the left side of the diagram is the front view, the processor is located on the surface, the surface can normally add structural members to cool the processor, because the processor has complex functions, the number of layers of the printed board on the surface is more, the thickness of the printed board is larger, and the rigidity is higher, so the surface is not provided with a reinforcing pressing strip; the right side of the diagram is the back view, and the DDR memory card is located on the surface. The two surfaces are interconnected by using a male snap connector, and the DDR particles occupy the space at the bottom of the processor.

[0045] It can be understood that for those skilled in the art, equivalent replacement or change can be made according to the technical scheme and the inventive concept of the present application, and all these changes or replacements shall belong to the protection scope of the claims attached to the present application.

Claims

1. A method of DDR bus interconnection design based on the snap button connector, interconnecting the DDR memory card with the functional module containing the processor through the snap button connector, characterized in that The pin impedance of the connector is controlled to be 45±5Ω for single-ended signal and 75±8Ω for differential signal. The impedance of the wire directly connected with the connector in the functional module with processor is consistent with the impedance of the connector. The connector is filled with sufficient copper wire to ensure the uniformity of the pins. The pin length of the connector is set to 5mm, the compression amount is 1mm, the shell height of the connector is 4±0.03mm, and the DDR memory card is installed on the back of the processor. The pin pitch of the connector is set to 1mm. The connector is set to be double-sided floating, which eliminates the soldering process. A positioning pin is arranged on the connector, and a positioning hole is arranged on the corresponding position of the functional module with processor and the DDR memory card.

2. The DDR bus interconnection design method based on the pinhead connector according to claim 1, characterized in that One mounting hole is arranged on each side and the middle of the connector shell, and mounting holes are also arranged on the corresponding positions of the DDR memory card and the functional module with processor, so that the DDR memory card, the connector and the functional module with processor are fixed through screws.

3. The DDR bus interconnection design method based on the pinhead connector according to claim 1, wherein The diameter of the mounting hole on the connector shell is 2.3±0.2mm.

4. The DDR bus interconnection design method based on the pinhead connector according to claim 3, characterized in that Two mounting holes are arranged on the DDR memory card and the functional module with processor, and a 4mm high stud is used to assemble between the DDR memory card and the functional module with processor.

5. The DDR bus interconnection design method based on the button connector according to claim 3, characterized in that A pressing strip is arranged on the outside of the DDR memory card and the functional module with processor according to whether there is deformation.

6. The DDR bus interconnection design method based on the button connector according to claim 3, characterized in that The pressing strip is made of metal, and an insulating pad is arranged between the pressing strip and the functional module with processor and between the pressing strip and the DDR memory card.

7. The DDR bus interconnection design method based on the button connector according to claim 6, characterized in that ​

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