KR200443273Y1 - Interface circuit for function unit of multi-chip system - Google Patents

Abstract

The present invention proposes an interface circuit of an input / output bus and a functional unit in a multi-chip system. The main object of the present invention is to remove the static voltage protection diode interposed between the independent power supply of the functional unit and the input / output bus line of the conventional functional unit interface circuit, so that the signal of the input / output bus is formed by turning off the independent power supply of the functional unit. Prevents distortion by the load. Another main feature of the present invention is to convert the negative voltage protection diode interposed between the earth and the input / output bus lines among the conventional functional unit interface circuits into a positive voltage type zener diode to ground high voltage static electricity through the zener diode to prevent static electricity and the functional unit. To achieve the purpose of protection.

Multi-Chip Systems, Function Units, Interfaces, Buses, Zener Diodes

Description

Functional unit interface circuit of multi-chip system {INTERFACE CIRCUIT FOR FUNCTION UNIT OF MULTI-CHIP SYSTEM}

1A is a view showing the inside of a conventional multi-chip memory card;

1B illustrates an internal circuit of a conventional multichip system.

1C illustrates an internal circuit of another conventional multichip system;

1D is a view for explaining that a conventional multi-chip system forms a low resistance path when the power of the functional unit is turned off alone;

2A is a signal waveform diagram of an input / output bus of a conventional multi-chip system in the case of normality;

2B is a signal waveform diagram of an input / output bus of a conventional multi-chip system when the power supply of the functional unit is turned off alone;

2C is a signal waveform diagram of an input / output bus of a multi-chip system of the present invention when the power supply of the functional unit is turned off alone.

3A is a diagram illustrating an internal circuit of a multi-chip system according to an embodiment of the present invention,

3b illustrates an interface circuit of a community main control unit and a functional unit according to an embodiment of the present invention;

3C illustrates an interface circuit of a community main control unit and a functional unit according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: multi chip memory card

10: I / O bus

12: I / O interface

20: function bus

22: USB port

30: memory controller

32: memory

40: controller

100: I / O bus

102: I / O interface

104: control signal

106: bus line

V1, V2: power

V3, V4: Power

200, 210: Function Bus

202, 212: functional interface

300: community main control unit

302: Capacity

304, 404: Core Logic

306, 406: Positive Voltage Protection Diodes

308, 408: negative voltage protection diode

400, 410: functional unit

500, 510: buffer

600, 610: function unit

402, 602: Capacity

604: Core Logic

606: Diode

608: Zener Diode

TG: lowest level of the signal

The present invention relates to a multi-chip system, and more particularly, to an interface circuit for connecting an input / output bus and a functional unit of a multi-chip system.

Since 2000, the System on Chip (SoC) has been mainstream in the semiconductor design industry. However, because SoCs have high complexity and long design periods, the market tends to adopt so-called System in Package (SiP) or Multi-chip Package (MCP) in consideration of purchase price and mass production time. Appearing. SiP means that two or more chips are mounted in a package, and passive devices such as capacitance, resistors, connectors, and antennas are also mounted together. There are several types of SiP, and the arrangement of the chip is planar arrangement or three-dimensional stacking to reduce the package area, and the bonding technology inside is simple wire bonding or flip chip, and both are used. You may also do it.

Conventional SiP is mainly applied to the memory and memory card of a mobile phone, which requires the mobile phone to simultaneously have three functions: program code reading, frequency application buffer, and multimedia storage. This is because it is necessary to have Flash, NAND Flash, and Pseudo SRAM at the same time. In addition, because memory chips have similar sizes, bonding, standardized electrical characteristics, and many chip suppliers, mobile phone memory and memory cards adopt the concept of SiP before other IC products. Accordingly, the present invention will be described below with reference to a multi-chip memory card as an example, but the 'multi-chip system' is a conventional SiP package or a package product including a plurality of similar chips that may appear in the future. It is called total.

The multi-chip system itself has a problem that cannot be solved. One of them is that each chip is supplied from a different supplier, and thus, a complex power management line is required due to different supply voltages, which causes power waste or circuit noise. FIG. 1A is a view showing the inside of a conventional multi-chip memory card. The multi-chip memory card 1 shown in FIG. 1A is a portable electronic device such as a mobile phone, a digital camera, an MP3 player, a PDA, or the like due to the multimedia file storage. It is a memory card that can be inserted and inserted into the USB port of a desktop or notebook computer. Accordingly, the multi-chip memory card 1 shown in FIG. 1A includes an input / output bus 10 connected to an input / output interface 12 of a portable electronic device and a function bus 20 connected to a USB port 22 of a computer. Have The read / write of the memory 32 of the multi-chip memory card 1 is controlled by the memory controller 30, and the input / output of the USB port 22 of the computer is controlled by the controller 40 via the function bus 20. Controlled. The portable electronic device and the computer perform read / write to the memory 32 through the input / output bus 10.

The structure shown in FIG. 1A is a kind of multi interface card reader 1. For example, the memory 32 and the memory controller 30 of FIG. 1A are micro SD cards (as shown by dashed blocks in the figure) that are coupled into the card reader 1 by the card insertion method. The input / output interface 12 is an SD interface. By such a design, the micro SD card in the card reader 1 can be inserted into a portable electronic device such as a mobile phone, a digital camera, an MP3 player, a PDA, etc., which does not have the interface of the micro SD and has only the SD interface. The card reader 1 may also be inserted into the USB port of the desktop computer or the notebook computer through the USB port 22.

An internal circuit of a multi-chip system similar to the structure shown in FIG. 1A is shown abstractly in FIG. 1B. As shown, the multi-chip system includes at least community main control unit 300 and at least one functional unit (both two functional units 400 and 410 are shown in the figure). Multi-chip systems actually have more functional units, only two are shown for simplicity. Taking the multi-chip memory card 1 as an example, the community main control unit 300 is a memory controller 30. The community main control unit 300 functions to connect and control peripheral function units 400 and 410 like the CPU of the multi-chip system to complete the functions of the respective terms. The function units 400, 410 have respective function buses 200, 210 and function interfaces 202, 212 (like the USB port 22), like the controller 40 of the multi-chip memory card 1. . The community main control unit 300 and the functional units 400 and 410 are all connected to the input / output bus 100. In addition to performing data exchange through the input / output bus 100, various control signals 104 may also be input / output buses ( Exchange through 100). In addition, the input / output bus 100 is connected to the input / output interface 102 of the multi-chip system. It should be noted that if the multi-chip system of Fig. 1B is the memory card shown in Fig. 1A, the memory chip (dashed block in the figure) is naturally included. In addition, the 'unit' described herein includes not only the main chip but also its associated passive elements, which are shown in the drawings for simplicity.

Note that the community main control unit 300 and the functional units 400 and 410 both have their respective operating power supplies V1, V2 and V3. For example, when a multi-chip system is connected to any electronic device, usually V1, V2 and V3 all receive power supplied from the electronic device through an input / output interface or a functional interface, and through an appropriate conversion circuit (not shown). After conversion to the appropriate voltage, they are supplied simultaneously to each unit. However, since not all functional units need to be run, this configuration places an unnecessary burden on the power supply (i.e., no such large power is originally required), and also generates unnecessary power waste. As a result, a structure as shown in FIG. 1C has been proposed (the control signal 104 has been omitted for simplicity), and a buffer switch 500 or 510 is provided between the functional units 400 and 410 and the input / output bus 100. If the function unit 410 only needs to supply power, the power supply of the function unit 400 is stopped (X is indicated next to V2) and the buffer 500 is controlled to control the function unit 400. I / O bus 100 is separated (the purpose of separation will be described later). However, since the buffers 500 and 510 themselves are not interrupted but need to be supplied with the power supply V4, there is a limit in reducing the power supply burden, and consequently, the installation cost of the buffers is generated. In addition, due to the installation of buffers, the area and cost of the line layout of a multi-chip system are greatly increased. In particular, the buffer does not necessarily provide sufficient stability when connected to an input / output bus of high bit number and high speed transmission.

In addition, if the buffers 500 and 510 are not provided using FIG. 1C as an example, the input / output bus causes signal distortion. 2A is a signal waveform diagram of an input / output bus of a conventional multi-chip system in a normal case. If normal (i.e. all units are powered or buffered), the signal level is higher than the lowest level TG that can correctly identify the signal. However, when the power supply of a functional unit that does not need a buffer or does not need to be driven alone is turned off, the signal is deformed as shown in FIG.

The cause of signal distortion is shown in FIG. 1D. For the sake of simplicity, FIG. 1D shows only the community main control unit 300 and the functional unit 400 with the power supply V2 off since no running is required. The core logic portions of community main control unit 300 and functional unit 400 are also simplified to both blocks 304 and 404 in the figure. Taking the bus line 106 which is one of the input / output buses 100 as an example, the positive pressure is applied to the interface where the core logic 304 and 404 of the community main control unit 300 and the function unit 400 are connected to the bus line 106. Protection diodes 306 and 406 and negative voltage protection diodes 308 and 408 are disposed. Diodes 306 and 308 are arranged in series between power supply V1 and ground in opposite directions, and diodes 406 and 408 are similarly arranged in series between power supply V2 and ground in opposite directions. The purpose of installing diodes at the interface of the I / O bus is to protect the community main control unit and the functional unit from being destroyed by high voltage static electricity. When high voltage static electricity occurs, the functional unit 400 is grounded through the diode 406 and the capacity 402 along the broken line in the drawing. The community main control unit 300 is grounded via a diode 306, a capacity 302. However, when V2 is not supplied, the signal path shown in FIG. 2A is lowered like the signal level shown in FIG. 2B because the current path indicated by the broken line in the figure forms a low resistance load on the input / output bus 100. The waveform is distorted, affecting the accuracy of the data transfer.

The main object of the present invention is to propose an interface circuit between a functional unit and an input / output bus in a multi-chip system. By adopting the multi-chip system of the present invention, the following effects can be obtained. (1) Each functional unit in a multi-chip system can be powered independently, thus avoiding unnecessary power burden and power loss, and (2) eliminating the need to separate the functional unit and I / O bus through the buffer, The cost of the product can be saved, and (3) the signal on the input / output bus is not distorted even when the power supply of any functional unit is turned off, and (4) the core logic of the functional unit can be protected from being destroyed by high voltage static electricity. have.

The main feature of the present invention is to remove the static voltage protection diode interposed between the independent power supply of the functional unit and the input / output bus line of the conventional functional unit interface circuit, so that the signal of the input / output bus is formed by turning off the independent power supply of the functional unit. It is to prevent distortion by.

Another main feature of the present invention is to convert the negative voltage protection diode interposed between the earth and the input / output bus lines of the conventional functional unit interface circuit into a positive voltage zener diode to ground the high voltage static electricity through the zener diode to prevent the static electricity and the functional unit. To achieve the purpose of protection.

The foregoing, other objects and advantages of the present invention will be described below in conjunction with the accompanying drawings, detailed description and claims. However, these accompanying drawings are used only for reference and description, and do not narrowly limit the scope of the present invention. See the appended claims for the definition of the scope of the invention.

The main object of the present invention is to propose an interface circuit for a function unit and an input / output bus in a multi-chip system. The present invention is applied to a multi-chip system manufactured in a SiP, MCP package method known in the present, or a package method including a plurality of similar chips that may appear in future. The most typical examples of multichip systems include multichip memory cards (such as MMC, SD, Micro-SD, etc.) used by mobile phones, digital cameras, MP3 players, PDAs, desktop computers, and notebook computers. Can be applied), the present invention is not limited to these. For example, the present invention may be a card reader in which the community main control unit or functional unit is coupled to a multi-chip system by the card insertion method. For the sake of simplicity, the following specification does not particularly emphasize whether a community main control unit or a functional unit is coupled to a multi-chip system by the card insertion method.

3A is a diagram illustrating an internal circuit of a multi-chip system according to an embodiment of the present invention. As shown in the figure, a multi-chip system includes at least a community main control unit 300 and at least one functional unit (both two functional units 600 and 610 are shown in the figure). The community main control unit 300 and the individual functional units 600 and 610 are each supplied with independent power sources V1, V2 and V3, among which the community main control unit 300 is always supplied with a power source V1. The power units V2 and V3 are individually supplied to or disconnected from the functional units 600 and 610 according to whether the functional units 600 and 610 are used. Other related details may refer to the description of FIG. 1B.

FIG. 3B is a diagram illustrating the interface circuits of the community main control unit 300 and the functional unit 600 of the multi-chip system of FIG. 3A. Comparing FIG. 3B with FIG. 1D, the prior art, it can be seen that the community main control unit 300 has a conventional interface circuit structure. The functional unit 600 also has a core logic 604, a capacity 602, and the like, like the conventional functional unit. However, at the interface connected with the input / output bus 100, two conventional series diodes have been switched to the zener diode 608 having an appropriate breakdown voltage. Among them, the cathode of the zener diode 608 is connected to the bus line 106, and the anode is grounded with the earth.

The action of the zener diode 608 is to protect the core logic 604 of the functional unit 600 from being destroyed by high voltage static electricity. If static electricity is generated to exceed the breakdown voltage of the zener diode 608, the core logic 604 is not damaged because the zener diode 608 penetrates in the opposite direction and grounds the static electricity along the broken line in the drawing.

When the operation of the functional unit 600 is not necessary, the supply of the voltage V2 is turned off to save power consumption. Note that the current path from the bus line 106 shown in the prior art to the power source V2 has been omitted in the present invention. On the other hand, if the breakdown voltage of the zener diode 608 is greater than the signal level on the input / output bus 100, the zener diode 608 cannot penetrate in the opposite direction, thus forming a low resistance load along the broken line in the figure. In other words, the signal of the input / output bus 100 is not distorted even if the power supply of any functional unit is turned off.

As shown in FIG. 3C, the Zener diode 608 of the present invention may be switched to the general diode 606. In this embodiment, since the signal of the input / output bus 100 is not distorted even when the power supply of any functional unit is turned off, the diode 306 and the capacitor of the community main control unit 300 are generated even when high voltage static electricity is generated in the input / output bus. It may be grounded through city 302 to achieve a protection function.

3B and 3C, the interface circuit employed by the community main control unit 300 is the same as in the prior art. However, the interface circuit proposed by the present invention may be implemented in the community main control unit 300. However, since the power supply V1 is always supplied to the community main control unit 300, the present invention performs only the static electricity protection function for the community main control unit.

In addition, since practically all functional units of a multi-chip system are not limited to having a power source that is independent or off as needed, the embodiments proposed by the present invention have some functional units (i.e., having power sources that are off or on demand off). It may be implemented for some units) or for all functional units (i.e. all units having power supplies that are independent or off as required). Implementing the embodiment shown in FIG. 3C (that is, the embodiment using a general diode) to all the functional units requires that the community main control unit have a positive voltage protection diode or similar protection means, so that high voltage static electricity is generated on the input / output bus. In this case, the protection function may be achieved by grounding through a constant voltage protection diode of the community main control unit 300 or similar protection means.

According to the present invention, since (1) each functional unit of a multi-chip system can be independently powered, it can prevent unnecessary power burden and power loss, and (2) separate the functional unit from the input / output bus through a buffer. There is no need to save the cost of the product, (3) the signal on the input / output bus is not distorted even when the power supply of any functional unit is turned off, and (4) the core logic of the functional unit is not destroyed by high voltage static electricity. Can be protected.

The detailed description of the preferred embodiment described above is intended to deeply and specifically understand the features and spirit of the present invention, and the above-described preferred embodiments do not limit the scope of the claims of the invention. On the contrary, various modifications and equivalent equations are included within the scope of the claims of the present invention.

Claims (5)

The multi-chip system includes at least one community main control unit, at least one functional unit, and an input / output bus for connecting the community main control unit and the functional unit. A multi-chip in which the community main control unit and the functional unit are driven respectively, and the power supply of the functional unit can be opened and closed independently as needed, and an interface circuit of the functional unit is interposed between the input / output bus and the functional unit. In the functional unit interface circuit of the system, The interface circuit includes a zener diode having a breakdown voltage at least greater than the signal level on the input / output bus, an anode connected to the earth of the multi-chip system, and a cathode connected to one bus line of the input / output bus. The functional unit interface circuit of the multi-chip system. delete The multi-chip system includes at least one community main control unit, at least one functional unit, and an input / output bus for connecting the community main control unit and the functional unit. The community main control unit and the functional unit are respectively driven, and the power supply of the functional unit can be independently turned on and off as necessary, and the interface circuit of the functional unit is interposed between the input / output bus and the functional unit. In the functional unit interface circuit of a multi-chip system, The interface circuit comprises at least an anode connected to the earth of the multi-chip system and a cathode connected to one bus line of the input / output bus, At least one of the community main control unit and the functional unit is connected to the multi-chip system in a card insertion manner. The method of claim 1, At least one of the community main control unit and the functional unit is connected to the multi-chip system in a card insertion manner. delete

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