KR101028806B1 - Communication apparatus of soc network applicable to various communication methods - Google Patents

Abstract

PURPOSE: A communication device of a SoC network capable of applying various communication method according to a data transmission method is provided to obtain network structure corresponding to a communication method with a existing various protocols through usage of a linker of other structure. CONSTITUTION: A router(110) has a plurality of links(130-1~130-3). The router determines data transmission path about a communication request signal. A network interface(120-1~120-5) starts communicating among an IP(Intellectual Property) or a local network and the router if a communication permission signal is inputted from the router. The linker interlinks the router(110-1) and a neighboring router(110-1). According to data transmission method between the routers, linker has a supportable structure of a corresponding data transmission method.

Description

Communication apparatus of SoC network applicable to various communication methods

The present invention relates to a communication device of the SOS network applicable to various communication methods, and more particularly, to a device for the communication for the exchange of data in and out of the SOS (System on Chip: SoC). .

Conventional on-chip bus or off-chip bus each use a different communication scheme, and look at them according to the communication scheme as follows.

First, the shared bus based on-chip bus, represented by AMBA AHB, communicates in such a way that the master initiates communication and the slave responds to it. The channel must remain open while communication is in progress, and other IPs cannot use the channel. In addition, since there is a response to communication for one data, communication for the next data can be performed so that the channel must be directly connected by wire so that performance does not occur. If communication is performed with a latency through a register or the like, the communication performance is drastically degraded. This type of bus architecture requires high latency between the two IPs or devices that communicate with each other, making it difficult to increase the operating frequency or expand the system.

On-chip buses or networks represented by AMBA AXI can be register-sliced, allowing for as much latency as needed between the master and slave. In order to prevent performance degradation due to the incubation period, the transmission request signal and the response signal are transmitted separately, and mainly perform burst-based communication. In addition, communication in an out-of-order transaction completion and outstanding address scheme is possible. However, when connected to an on-chip bus such as AMBA AHB, which does not support these characteristics, communication performance is degraded.

The off-chip bus, represented by PCI-e, communicates through the PCB, reducing the channel width in consideration of cost and operating frequency, and using the operating frequency different from the on-chip. Therefore, data generated from on-chip requires a process of converting a data width and changing a transmission rate according to a difference in operating frequency for off-chip communication. There is a performance penalty in this process.

In the case of a network-on-chip (NoC), communication occurs between a large number of calculators, and the generated data is transmitted through an internal network in a packet manner. Therefore, virtual channels are often used to prevent deadlocks and improve communication efficiency caused by many data packets transmitted inside the network. This makes it possible to overtake or temporarily store packets inside the network. To achieve this goal, one basic communication unit generally consists of a total of five ports, including four communication ports connected to other communication units and one port for IP. This is a structure that emphasizes connectivity for communication, and it is not suitable for being applied to a system using an on-chip bus such as AMBA AHB.

The four communication methods mentioned above require different network structures. However, when designing a complex system, it is difficult to construct a network using only one communication method. Therefore, when two or more communication methods are mixed, a signal conversion process is required every time the boundary is crossed, which may not only reduce communication efficiency but also make system design, modification, and verification difficult.

An object of the present invention is to provide a communication device of the SOS network to integrate the bus or network structure used in various existing communication schemes into one to enable data transfer without a separate signal conversion process.

In order to achieve the above technical problem, the communication apparatus of the SOS network applicable to various communication methods according to the present invention, has a plurality of links consisting of input and output ports independent of each other, and the data for the received communication request signal A router determining a transmission path to form a channel for data transmission in an SOS network; Connected to an IP (Intellectual Property: IP) or a local network that transmits data to a destination of the SOS network, and transmits a communication request signal to the router, and when a communication permission signal is input from the router, the IP or local network and the A network interface for initiating communication between routers; And a linker having a structure designed to connect the router and the adjacent router to each other to transmit a communication request signal in both directions, and to support a corresponding data transmission method according to a data transmission method between the router and the adjacent router.

According to the communication device of the SOS network applicable to various communication methods according to the present invention, by using a linker having a different structure according to the data transmission method SOS may have a network structure corresponding to various existing protocols and communication methods The structural flexibility can be improved when designing the network based. In addition, by designing and applying the network structure without changing the structure of the existing system, the network structure can be improved while reducing the burden of redesigning or verifying the entire system. Furthermore, the system design is possible with little effort due to the flexible network structure when changing or expanding the system structure.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the communication device of the SOS network applicable to various communication schemes according to the present invention.

FIG. 1 is a diagram illustrating a configuration of a preferred embodiment of a communication device of an SOS network applicable to various communication methods according to the present invention.

Referring to FIG. 1, a communication device of an SOS network according to the present invention includes a router 110, a network interface 120 (hereinafter referred to as NI), and a linker 130. Hereinafter, in the present invention, the SOS network is used to mean not only the SOS internal network but also a connection between SOS, that is, a network based on the SOS structure. The router 110 performs the functions of channel formation and data transmission, and the NI 120 connects the router 110 to an IP (Intellectual Property (IP)) or a local network, and the linker 130 connects to the router 110 and Connect another adjacent router (110-1). IP is a design asset required to implement SOS network structure on a chip, and is designed in advance to realize the required function. In addition, the local network is a network structure in which a plurality of IPs are connected by a bus structure, and are connected to the NI 120 through a bridge device. In FIG. 1, the link indicated by the dotted line is for signal transmission between the NI 120 or linker 130 and the router 110, and the link indicated by the solid line is for transmitting data and address information transmitted from the IP.

A communication device of the SOS network according to the present invention can be connected to a plurality of linkers 130 through each other, and thus a network structure consisting of a plurality of communication devices of the SOS network in the following unified SoC network structure (Unified SoC Network Architecture, USNA). USNA was developed to solve the inconvenience of signal conversion under a unified interface protocol by enabling the use of various conventional bus or network structures in one. In USNA, the IP 120 or the local network may be connected to the router 110 through the NI 120, and the network may be extended by adding the router 110 using the linker 130.

The router 110 has a plurality of links composed of input and output channels independent from each other, and determines a data transmission path with respect to the received communication request signal to form a channel for data transmission in the SOS network.

2 is a conceptual diagram illustrating an internal structure of the router 110. Referring to FIG. 2, the router 110 is composed of two functional modules of routing logic and a switch matrix. The routing logic looks for the destination link in the internal look-up table (LUT) according to the priority when the destination address and communication request are input from the outside, and sends the channel control signal to the switch matrix when the destination link is determined to be available. Send to form a channel. The switch matrix provides a physical channel for data transmission according to the input channel control signal. If it is determined that the destination link is not available, no channel is formed, and the NI 120 continues to send communication requests until a grant signal is received from the router 110, so routing logic resumes channel creation in the next cycle. Will try.

In the internal structure of the router 110 illustrated in FIG. 2, all information transmitted through a link indicated by a dotted line is input to the routing logic, and in the case of a link indicated by a solid line, some of the information transmitted for routing is required by the routing logic. Only information is optionally entered.

In addition, the router 110 shown in the drawing has a rectangular shape in which eight links are provided, but the number of links may vary depending on the structure of the router 110. That is, the router 110 may be designed in various forms such as a triangle having six links, a pentagon having ten links, and a hexagon having twelve links. If only a rectangular router 110 is provided so that the system is completely configured by one router 110, in order to add one IP to the system, one router 110 is added or one of the routers 110 is added. The link of the node must be reconfigured to be connected to the bridge and the local network. However, when various types of routers 110 are provided as described above, flexibility of the topology may be improved.

When the shape of the router 110 is triangular or square, the number of IPs that can be connected to one router 110 is small, but the operation speed of each router 110 is increased, and the area occupied is reduced. However, as the number of links included in the router 110 decreases, the number of links required to pass through another router 110 using the linker 130 for data transmission to the destination increases, thereby increasing the overall routing cycle. On the other hand, when the shape of the router 110 is pentagonal or hexagonal, the number of IPs that can be connected to one router 110 increases, but the operation speed of each router 110 is somewhat reduced, and one router 110 ) Area increases. However, the number of routing cycles does not increase greatly because the number of data transmissions required through other routers 110 is reduced. In this way, the network structure can be flexibly designed by selecting the type of router 110 suitable for the characteristics of each system in consideration of the trade-off relationship generated according to the shape of the router 110.

The number of channels that can be formed in the same cycle in one router 110 is determined by the structure of the routing logic, and the number of simultaneously open channels is equal to the number that all links can communicate at the same time unless collision occurs. Can be. In addition, when the required bandwidth is small, the internal structure of the router 110 may be simplified by reducing the number of channels that can be simultaneously communicated.

FIG. 3 is a diagram for describing a process in which routing occurs in the router 110 having a structure as illustrated in FIG. 2.

As described above with reference to FIG. 2, all information necessary for routing is input from all links of the router 110 into the routing logic inside the router 110. In FIG. 3, routing logic receives information necessary for routing from all eight links.

Priority logic of the routing logic selects and passes only information input from a link having a priority according to a priority policy set among preset information. According to the structure of the routing logic, the number of information to be selected may be selected for only one link or information for three or more links. In FIG. 3, information on two links is selected. At this time, as a priority policy for selecting information to be passed, various methods such as a static priority, a round robin method, a time divisional access (TDMA) method, and a rotary method may be used. have. In addition, when the network guarantees a quality of service (QoS), related logic is implemented inside the priority logic to participate in link selection.

The link information selected in the priority logic is converted into a signal suitable for the LUT input and input to the LUT. In general, the signal input to the LUT has a simplified form compared to the signal input from the link. In the LUT, the position of the link to be connected, that is, the destination link, is determined according to the input signal. In a network having a complicated structure including a large number of routers 110, the LUT may be complicated, and various methods for solving this problem may be applied to the configuration of the LUT. In addition, when the link to be connected is not an internal link of the router 110, since one or more paths may exist, all possible link information is output.

Next, a collision detector detects whether the destination link is the same when two or more routings occur simultaneously. As a result, when the destination link is the same, the channel control signal is generated only for the signal of higher priority and output to the switch matrix. If a collision does not occur because the destination links are different, a channel control signal for simultaneously generating two channels is output. When the formed channel is connected to the linker 130, two or more destination linkers 130 may exist, and after determining whether the channel is used by referring to the status signal of the corresponding linker 130, the linker that is not used One of the 130 is selected to form a channel.

The above-described routing process corresponds to one embodiment for explaining the operation of the routing logic, and the routing logic may determine the destination link by all possible methods and output a signal for channel formation to the switch matrix. . The structure of the routing logic also depends on the NI protocol and the designer's purpose.

The NI 120 is connected to an IP or local network that transmits data to a destination of an SOS network, transmits a communication request signal to the router 110, and receives a communication permission signal from the router 110. Initiate communication between routers 110.

When you want to transfer data from an IP or local network to a destination IP or local network, the NI 120 routes the communication request signal because the IP based on the point-to-point protocol cannot transmit the communication request signal. Transmit to 110. While the router 110 forms a channel based on the received communication request, the NI 120 waits for data, which is a transmission signal, and starts communication when a permission signal indicating that the channel has been formed is received from the router 110.

In addition, the NI 120 may be connected to an adjacent NI 120 connecting between another IP and the router 110. 4 is a diagram illustrating a data transmission path using a communication device of an SOS network according to the present invention. Referring to the path indicated by ① in FIG. 4, two NIs 120-2 and 120-3 connected to two neighboring links of the router 110 are connected to different IPs, and two NIs are connected to different IPs. 120-2 and 120-3 are connected to each other. As described above, the NIs 120-2 and 120-3 connected to each other store an IP or local area of an IP network connected to the counterpart NI.

As indicated by the arrow direction ①, when you want to transfer data from the upper IP to the lower IP, the lower IP address is stored in the NI 120-2 connected to the upper IP. If it matches the address of the lower IP, the router 110 does not transmit a communication request but transmits the communication request to the counterpart NI, that is, the lower NI 120-3. Upon receiving the communication request, the lower NI 120-3 enables communication immediately through the connection with the lower IP connected to the lower NI 120-3 if it is not currently communicating. This type of connection is called a direct connection, and supports dedicated communication that can be made directly between IP or local networks. When data transmission is performed through such a direct connection, routing is possible without using any resources of the router 110, so that additional bandwidth may be provided, thereby improving network performance.

The linker 130 has a structure designed to connect a router and an adjacent router to each other to transmit a communication request signal in both directions, and to support a corresponding data transmission method according to a data transmission method between the router and the adjacent router.

Since the aforementioned NI 120 connects the IP and the router 110, the NI 120 receives a communication request only from the IP and transmits the communication request to the router 110. Therefore, the functions of the connection part with the IP and the connection part with the router 110 are different from each other. However, since the linker 130 connects the two routers 110 as shown in FIG. 1, when the communication request is received from one of the routers 110, the linker 130 transmits the received communication request to the other router 110-1. send. Therefore, the linker 130 functions as a bidirectional NI 120 and performs symmetrical operation. In addition, linkers 130 can be connected to adjacent NIs 120, as well as adjacent NIs 120-2 and 120-3s that are connected together to support dedicated communication between IP or local networks. Connected to 120 may support data transmission through a direct connection.

USNA supports two routing modes: direct connection and network routing. In FIG. 4, the network connection, which is a data transmission path indicated by ②, refers to all routing through a channel generated by the router 110. That is, the network connection is data transmission through two NIs 120 connected to one router 110, that is, the path on the left side of the path ② of FIG. 4, and two adjacent routers using the linker 130. 110, 110-1) includes data transmitted through the channel generated over the path, that is, the right path among the ② path of FIG.

In the case of data transmission through the linker 130, since the linker 130 performs the functions of the NI 120 on both sides of the two routers 110 and 110-1 connected thereto, the entry of the router 110 is performed. Treats the linker 130 and the NI 120 in the same manner. As such, operating as the NI 120 for the routers 110 and 110-1 connected to both sides may be an important technical feature of the linker 130.

On the other hand, another important technical feature of the linker 130 relates to a feature of USNA that provides a unified interface protocol, and controls the connection of the signal. The configuration of the linker 130 for controlling the signal connection depends on the protocol used and the structure of the system.

5 is a view showing the structure of the linker 130 used for a simple wire connection. Referring to FIG. 5, the linker 130 immediately outputs an input signal, that is, an address and data, to an output. In this case, if the channel generation is not guaranteed in the cycle in which the signal is input from the router 130, the router 130 may have a function of storing an address or a header.

6 is a diagram showing the structure of the linker 130 applied to a network using register slicing. Referring to FIG. 6, an input signal is output through a register provided in the linker 130, and data is stored according to the handshake signal. At this time, the linker 130 should generate a communication request signal at an appropriate timing so that the input address or data does not stay in the register more than necessary.

FIG. 7 illustrates a structure of a linker 130 used in a network using a virtual channel as in NoC. Referring to FIG. 7, there are buffer memories corresponding to the number of virtual channels in the linker 130, and one buffer may store one packet. In this case, since the linker 130 should be able to interpret the header portion of the packet, the linker 130 has a different structure according to the protocol.

8 is a diagram illustrating a structure of a linker 130 connected between routers 110 having different frequency domains or data widths. Referring to FIG. 8, linker 130 has a synchronizer and means for converting the size of the input data. This feature is useful for off-chip communication, because the operating frequency and data width typically vary.

In addition to the structure illustrated in FIGS. 5 to 8, the linker 130 has a structure capable of supporting all kinds of communication required between the routers 110, and may be designed and used in various structures according to a system to be designed. Therefore, even if a system is composed of several chips and there is an SoC including a NoC structure inside the chip, the system can be designed using one network structure and protocol.

When designing the network structure, it is possible to design the appropriate structure according to the characteristics of the system by adjusting the ratio of communication function and arithmetic function. For example, when designing a network to replace an on-chip bus such as AMBA AHB, one or two routers 110 are used to maximize the placement of IP, and communication between routers 110 In consideration of this, it may be performed using one or two linkers 130.

In addition, when applied to the NoC structure it is possible to increase the communication bandwidth between the router 110 by using four or more linkers (130). Particularly, in a location where communication is concentrated, only the linker 130 is used to perform a communication function, and in a place where there is not much communication, the number of calculators can be increased to increase the execution rate of the calculation function, thereby improving the efficiency of the overall system. have. This allows existing NoCs to be optimized for specific systems and overcome the lack of flexibility. Therefore, USNA can implement communication networks of all existing SoC-based systems. This is an important effect of the present invention obtained by using the linker 130 that can be designed in a variety of structures depending on the system characteristics.

Hereinafter, various system network configurations designed using the communication device of the SOS network according to the present invention will be described.

9 is a diagram illustrating an example of a system network configuration using the present invention. In FIG. 9, R0 to R4 are routers 110, and blocks denoted by L0 to L6 represent linkers 130. The remaining blocks represent the NI 120 and its associated IP. The network of FIG. 9 is composed of all five routers 110, and the number of NIs 120 and linkers 130 connected to each router 110 are different from each other. In the case of R0, only one linker 130 is connected and the remaining seven links are all connected with the NI 120 and IP. However, a large amount of calculation is performed, but communication inside the router 110 is mainly performed and out of the router 110. It can be seen that the traffic is low. On the other hand, R2 is located in the center of the network and communication with other routers 110 is actively performed. Therefore, in order to secure the bandwidth, all five linkers 130 are connected to perform a communication function as compared to a calculation function.

Looking at the other routers 110, since R1 mainly communicates with R2 and R3, L1 and L2 are connected, and R3 has three linkers for communication with R1, R2, and R4. Finally, R4 primarily communicates with R2 and R3. Infrequent communication does not need to be directly connected through the linker 130 because data is transmitted through the intermediate router 110. As such, the linker 130 may be disposed at an appropriate position according to the demand of the communication amount to obtain an optimal communication efficiency.

As described above, the structure of the linker 130 to be connected may use a structure according to a direct connection method or a register slicing method according to a protocol. That is, when using a stop and wait method of bidirectional communication such as AHB, a linker 130 of a direct connection method as shown in FIG. 5 is used, and a unidirectional method that allows register slicing as in AXI. In the case of communication, the linker 130 of the register slice method as shown in FIG. 6 is used.

10 illustrates an example of applying USNA to NoC. Referring to FIG. 10, routers R0 to R8 are arranged in a 3 × 3 structure, and the shaded blocks represent the linker 130 and the remaining blocks represent the NI 120 and the IP connected thereto. In addition, the linkers located in the outer side of the linkers 130 are expressed to have a thickness of 1/2 compared to the linker 130 connected to the two routers 110, which is the linker 130 on the opposite side It is the same as other linker 130 that is present. For example, the linker 130 connected to the upper left of the router 110 R0 is the same as the linker 130 connected to the lower left of the R6, indicating that R0 and R6 are connected by the linker 130. The same is true of linkers 130 connected to the edges of the other routers 110.

Referring to FIG. 10, in the case of a general NoC, one IP exists in one router and four other routers are connected. However, USNA according to the present invention has four IPs and four routers in one router 110. 110 may be connected, and if necessary, bandwidth may be increased by reducing the number of IPs and increasing the number of linkers 130.

In FIG. 10, IPs connected to R0 and R8 must pass through at least two routers 110 in the middle in order to communicate with each other. However, routers 110 directly remove the IPs from R0 and R8 and connect the linker 130. To improve performance. In the existing NoC, this is not possible, and most of the components corresponding to the router 110 for a specific purpose are difficult to apply to other purpose systems. However, USNA allows flexible system design because the structure can be freely designed according to the characteristics of the system.

11 is a diagram illustrating an example of a structure in which various communication methods are simultaneously performed. Referring to FIG. 11, chip 1 and chip 2 perform off-chip communication with each other, and operate at 100 MHz with a 4-bit data width between chips. Inside Chip 1, operating at 50MHz with 64-bit data width, linkers L0 and L7 perform synchronization and data width conversion. Inside chip 2, domain 1 and domain 2 operate at different frequencies with different data widths. That is, domain 1 operates at 50 MHz with a 64-bit data width and domain 2 operates at 200 MHz with a 32-bit data width. At this time, the linker L1 performs synchronization and data width conversion to facilitate communication between the two domains. Therefore, when using the communication device of the SOS network according to the present invention, it is possible to design the entire system by applying the USNA in the multi-chip system, not SoC, and even if the requirements are different for each function through the linker 130 I can solve it.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific preferred embodiments described above, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

1 is a diagram showing the configuration of a preferred embodiment of a communication device of the SOS network applicable to various communication schemes according to the present invention,

2 is a conceptual diagram illustrating an internal structure of a router;

3 is a view for explaining a process in which routing occurs in the router;

4 is a diagram illustrating a data transmission path using a communication device of an SOS network according to the present invention;

5 is a view showing the structure of a linker used for a simple wire connection,

6 shows a structure of a linker applied to a network using register slicing;

FIG. 7 illustrates a structure of a linker used in a network using a virtual channel, such as in NoC. FIG.

8 illustrates a structure of a linker connected between routers having different frequency domains or data widths;

9 is a diagram illustrating an example of a system network configuration using the present invention;

10 is a view showing an example in which USNA is applied to NoC, and

11 is a diagram illustrating an example of a structure in which various communication methods are simultaneously performed.

Claims (13)

A router having a plurality of links composed of input and output ports independent of each other, and determining a data transmission path with respect to an input communication request signal to form a channel for data transmission in an SOS network; Connected to an IP (Intellectual Property: IP) or a local network that transmits data to a destination of the SOS network, and transmits a communication request signal to the router, and when a communication permission signal is input from the router, the IP or local network and the A network interface for initiating communication between routers; And And a linker having a structure designed to connect the router and the adjacent router to each other to transmit a communication request signal in both directions, and to support a corresponding data transmission method according to the data transmission method between the router and the adjacent router. Communication device of SOC network. The method of claim 1, The linker has a structure that directly connects the router and the adjacent router by a wire so that the input signal can be output immediately. The method of claim 1, And the linker has a structure including the register to provide a register slicing data transmission method in which an input signal is output through a register. The method of claim 1, And the linker has a structure including a buffer memory in which packets are stored to be applied to a network structure using a virtual channel. The method of claim 1, The linker may have a structure including a synchronizer and a means for converting data widths when data widths and operating frequencies used for data transmission in the router and adjacent routers are different from each other or when asynchronous signals are used. Communication device of SOS network. The method of claim 1, The linker converts the synchronizer and the data width when the data width and operating frequency used when off-chip communication is performed between the router and the adjacent router are different from the data width and operating frequency used inside the router and the adjacent router. Communication apparatus of the SOS network having a structure having a means for. The method according to any one of claims 1 to 6, The network interface is directly connected to the adjacent network interface so that data transmitted from the IP or local network is directly transmitted to the IP or local network connected to the adjacent network interface without passing through the router. . The method of claim 7, wherein The network interface stores address information of an IP or a local network connected to the adjacent network interface, and transmits the data to the adjacent network interface when a destination address input together with the data matches the stored address information. Communication device of SOS network. The method according to any one of claims 1 to 6, The linker is directly connected to two network interfaces so that data is directly transmitted between the IP or local networks connected to each of the two network interfaces without passing through the router. The method according to any one of claims 1 to 6, And the number of the network interface and the linker connected to each link of the router is determined according to the amount of communication generated in the router. The method according to any one of claims 1 to 6, The number of the links provided in the router is a communication device of the SOS network, characterized in that determined based on the number of the IP contained in the SOS network and the operating speed of the router. The method according to any one of claims 1 to 6, The router, If a destination address of a data transmission is input together with a communication request signal from the network interface or the linker through the link, a lookup table (LUT) searches for a destination link corresponding to the destination address, and the destination Routing logic for outputting a channel control signal for forming a data transmission channel when it is determined that the link is available; And And a switch matrix configured to receive the channel control signal and form a physical data transmission channel. The method of claim 12, The routing logic outputs a channel control signal for forming a plurality of data transmission channels to destination links corresponding to the respective destination addresses when the plurality of destination addresses input together with the communication request signal through the plurality of links are different from each other. And if the plurality of destination addresses are the same as each other, to a destination link corresponding to the destination address input through the link having the highest priority among the plurality of links based on the priorities previously set and stored in the internal reference table. And a channel control signal for forming a data transmission channel.

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