WO2005066807A1

WO2005066807A1 - Microcomputer and data receiving method

Info

Publication number: WO2005066807A1
Application number: PCT/JP2003/016855
Authority: WO
Inventors: Junichiro Takahashi
Original assignee: Renesas Technology Corp.
Priority date: 2003-12-26
Filing date: 2003-12-26
Publication date: 2005-07-21
Also published as: JP4252577B2; JPWO2005066807A1

Abstract

A microcomputer (1), which includes a central processing unit (2), a RAM (7) and a ROM (6), is formed in a single semiconductor chip. The ROM has stored therein an operating system, application programs, and TCP/IP processing programs that can be invoked from the application programs to be executed. The TCP/IP processing programs include processing programs of connection request, event waiting, data transmission and disconnection. When the central processing unit requires packet data by reading a portion of the packet data into the RAM in response to a data reception interrupt during execution of a processing program of event waiting, it starts up from the event waiting state to execute an application program to further import the corresponding packet data into the RAM.

Description

Description Microcombination and data receiving method

The present invention relates to the realization of a protocol with a small program capacity. More specifically, the present invention relates to a method for receiving a micro computer with a TCP / IP protocol stack. The present invention relates to technology that is effective when applied to home appliances that can be connected to a network. Background art

TCP / IP (Transmission 'Control Protocol / Internet Protocol) has evolved as a core network technology and is currently the de facto standard for communications. The details of the protocol are described in the huge number of RFCs (requests) compiled by the IETF (Internal Network Engineering 'Task Force'), an organization that solves the problems of the Internet. Various comments are defined. Conventionally, data communication using the TCP / IP protocol is conventionally performed by a software protocol stack processed by the CPU (central processing unit) and hardware that performs packet communication processing on the MAC (media 'access' control) layer. This is realized by the network interface.

Regarding the realization of the protocol stack, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2003-143221) provides a protocol stack by hardware that can be executed independently of the control of OS. 0 Protocol processing executed by software under S control is not blocked by other priority processing. In this way, we try to guarantee real-time communication processing.

In Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2003-263323), mounting a protocol block together with 0S increases the program capacity. To reduce this, a simple communication program and a self-rewriting program are included. In addition, the self-rewriting program makes it possible to upgrade the download function and deal with advanced functions. Disclosure of the invention

The present inventor has studied support for the TCP / IP protocol in network home appliances and the like. In particular, we examined TCP / IP protocol protocols that can operate on internal ROM / RAM such as a 16-bit microcomputer for embedded control. According to this, there is no idea that the already defined protocols will save resources extremely. Implementing the TCP / IP protocol according to the details of such a protocol requires a large storage ROM to store the protocol stack, and a large work RAM to execute the protocol stack. . The technology described in the above-mentioned patent document differs from the technology studied by the present inventor in the point of view. An object of the present invention is to make it possible to realize a network connection by a TCP / IP protocol for a small-scale system such as a network home appliance. Another object of the present invention is to provide a data processing method that can contribute to the realization of a compact TCP / IP protocol stack.

The above and other objects and novel features of the present invention will become apparent from the following description of the present specification and the accompanying drawings.

[1] A microcomputer according to the present invention is formed on one semiconductor chip including a central processing unit, a RAM, and a ROM, and the ROM is an operating system, an application program, and the application program. A TCP / IP processing program called and executed by the content program is stored. The TCP / IP processing program has a connection request, event waiting, data transmission, and connection disconnection processing programs. You. The central processing unit reads a part of the packet data into the RAM in response to an evening switch command, for example, a data overnight reception interrupt during execution of the processing program waiting for the event, and reads the packet data and needs the packet data overnight. Wakes up from the event wait state, executes the application program, and loads the corresponding bucket data into RAM.

A part of the received packet data in the MAC layer can be fetched into the on-chip RAM of the microcomputer and analyzed, so there is no need to process all the bucket data into the work RAM and expand it. The size of the work RAM to be used is small. Also, the process of loading the packet data into the on-chip RAM according to the result of the analysis is performed directly by the application program, and does not use the protocol block. Therefore, it can contribute to making the protocol stack compact. [2] A microcomputer according to another aspect of the present invention includes a central processing unit, a RAM, and a ROM, and is formed on one semiconductor chip. The ROM includes an operating system, an application program, and the application program. The RAM is used as a work area when the CPU executes the program, and the TCP / IP processing program is called a service program. It has a start, connection request, event wait, data transmission, and disconnection processing programs.

By giving the wake-up factor from the event waiting state to the event waiting processing program, it becomes possible to return to the application program and directly take in the necessary packet data and the like. As a specific form of the present invention, the events to wait for the event wait may be a connection establishment, a connection disconnection, a data reception, and an event wait timeout. The type of event to wait in the event waiting processing program is preferably specified by the application program. At this time, the event waiting processing program needs to take a predetermined bucket of the packet data from the outside into the RAM in response to a predetermined interrupt, and check the received data for a corresponding bucket. It is determined whether the bucket is a proper bucket or not, and if it is determined that it is necessary, the event waiting state is ended. Then, the application program may take in the data of the corresponding reception bucket into the RAM in response to the end of the data reception event waiting state.

In the microphone computer having the above configuration, the storage capacity of the on-chip RAM can be about 2 to 4 kilobytes.

[3] The data receiving method according to the present invention is a method of reading out a predetermined portion of packet data stored in a buffer memory of a communication device constituting a TCP / IP MAC layer, and reading the data from an on-chip RAM of a microcomputer. A first process for storing the data in the on-chip RAM, a second process for determining whether or not a corresponding bucket is necessary by checking the data stored in the on-chip RAM. And a third process for storing a necessary portion of the corresponding bucket data from the buffer memory in the on-chip RAM when it is determined that evening is necessary. If it is determined in the determining process that the packet data is unnecessary, the corresponding packet data is discarded. Discarding means not storing in on-chip RAM.

In the first process, a part of the received bucket data can be fetched into the on-chip RAM of the microcomputer and analyzed in the second process, so that all the bucket data is fetched and expanded in the peak RAM. Where Requires no work, and the required work RAM size is small.

The first process and the second process are defined by the protocol stack, and the third process is defined by the application program, so that the packet data is loaded into the on-chip RAM in accordance with the result of the analysis by the third process. The processing is performed directly by the application program and does not use the protocol block, so it can contribute to making the protocol stack compact. In a specific embodiment of the present invention, the data of the predetermined portion is data of 13 bytes to 42 bytes from the head of the packet format in the in-net protocol. It is evening. By analyzing up to this range, the ARP (Adresor Resolution Protocol) and I CMP (Inner Network Control Message) included in the TCP / IP protocol in a broad sense can be analyzed. Protocol, TCP, and UDP (user datagram protocol). Brief Description of Drawings

FIG. 1 is a block diagram of a microcomputer according to the present invention. Figure 2 shows the CUP's quadruple map.

Fig. 3 is an explanatory diagram showing the seven types of API programs held by the TCP / IP protocol.

FIG. 4 is an explanatory diagram showing a list of events recognized by the event waiting API program.

Fig. 5 is a flowchart of the bucket data overnight reception process by TCP / IP.

FIG. 6 is an illustration showing the packet format of the TCP / IP protocol in a broad sense.

Fig. 7 shows 42 bytes of bucket data from buffer memory FIG. 4 is an explanatory view schematically showing the appearance.

FIG. 8 is a flowchart showing details of the protocol analysis processing (S4) of FIG.

FIG. 9 is a flowchart of a passive connection process by TCP / IP. FIG. 10 is a flowchart of the active connection processing by TCP / IP.

FIG. 11 is a flowchart of the overnight transmission processing by TCP / IP.

FIG. 12 is a flowchart of the forced disconnection for the TCP / IP connection.

Fig. 13 is a flowchart of normal disconnection for TCP / IP connection. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a block diagram of a microcomputer according to the present invention. The micro-computer 1 shown in the figure is not particularly limited, but is formed on a single semiconductor substrate such as single-crystal silicon by a complementary MOS integrated circuit manufacturing technology or the like, and is configured as a single chip or a single chip. Pelletized and packaged as needed.

The microcomputer 1 is not particularly limited, but is rewritten as a CPU (central processing unit) 2, a clock oscillator 3, an interrupt controller 4, a DMAC (direct 'memory'access' controller) 5, and a flash memory. ROM (read-only-memory) 6, composed of possible non-volatile memory or mask ROM, RAM 7, composed of SRAM (static random access memory), refresh controller 8, clock Abnormal operation of the system due to the number of cycles Monitor WD T (Watch 'Dog' evening) 9, TCU (East 'Counter' unit) 10, SCI (Serial 'Communication' interface) 1 1, US Β (Universal 'Serial' It has a bus 12, an AD (analog-to-digital) converter 13, a bus controller 14, and an input / output port 15, which are connected to an internal bus represented by reference numeral 16.

Although not shown, the CPU 2 has an instruction control unit and an execution unit. The instruction control unit accesses a program stored in the ROM 6 or the like to fetch an instruction, decodes the fetched instruction, and generates control information. The execution unit executes an instruction by performing an operation, an operand access, or the like according to the control information. .

Although not particularly limited, the input / output port 15 is connected to an Ethernet device 20 constituting a network interface card (NIC). The Ethernet device 20 is connected to the Ethernet cable 21 and implements a network interface of hardware that performs bucket communication processing of the MAC layer. Although not particularly limited, the Ethernet device 20 includes an Ethernet controller 22, a buffer memory 23, and a transceiver / receiver 24 coupled to the Ethernet cable 21.

Micro-combination 1 is a protocol protocol for hardware that performs bucket communication processing and software that is processed by CPU 2 for data communication using the TCP / IP protocol. Use a TCP / IP processing program (also simply called TCP / IP protocol block). The TCP / IP protocol stack is called from the application program and executed. What is an application program? Browser software Email software And so on. The TCP / IP protocol and application programs are owned by the R0M6 together with the operating system (OS).

FIG. 2 illustrates an address map of the CPU 2. In the address space of R0M6, vectors, OS, TCP / IP protocol blocks, and application programs are arranged from the top. Application programs include programs other than data communication, and may be understood as so-called user programs that are incorporated as needed by the user of the microcomputer. In the address space of RAM7, there are an OS work area (OS work), a work area, a work area for TCP / IP protocol work (TCPZIP work), and a work area for application programs (user work). Is assigned.

Figure 3 shows the seven types of API programs held by the TCP / IP protocol. The service start API program is a processing program that performs initial settings for TCP / IP communication. The initial setting items include, for example, initialization of the Ethernet device 20, initialization of the TCP / IP work, and the like. The passive connection setting API program is a processing program that sets the IP address and port number of its own port in order to wait for connection. The active connection request API program is a processing program that sets the partner port that requests connection. The event waiting API program is a processing program that waits for a response to a setting or request. Data transmission API program is a processing program that transmits data. Closing a connection The API program is a processing program that disconnects its own connection and leaves the disconnection of the partner to the partner. Forcibly disconnecting the connection The API program is a processing program that forcibly cuts off both its own connection and the connection of the other side. Awaiting event API program starts a specified event It is a processing program for waiting for life.

FIG. 4 shows a list of events recognized by the API program waiting for events. The events to be recognized are: passive / active connection establishment to be confirmed after the execution of the passive connection setting API program or active connection API program, closing of the connection to be confirmed after execution of the closing API program, and forced disconnection of the connection API program To be confirmed after execution of data transmission, data reception indicating that data has been received, completion of data transmission to be confirmed after execution of the API program for data transmission, timeout of event waiting by event waiting API program (waiting)タイムタイム）、とと. Which event to wait for is indicated from the application program by a flag or the like.

FIG. 5 illustrates a flow chart of the bucket data overnight receiving process by TCP / IP. In the packet data overnight reception process, the service start API program is executed to complete the initialization of the communication settings, and then the passive connection setting or active connection setting API program is executed to establish the connection. It is assumed that Under this premise, the application program sets a flag for the overnight reception event, and the API program is called and executed while waiting for the event. The content of the execution by this is the processing of FIG. 5. First, it waits for a packet data—evening reception interrupt from the Ethernet device 20 (S 1).

The Ethernet device 20 sequentially receives the received packet data into the buffer memory 23, and outputs a reception interrupt of the packet data to the microcomputer 1 in response to the data reception. For example, the Internet Protocol Protocol Purge 4 has the format shown in Fig. 6 and uses the ARP (address resolution solution protocol) included in the broadly defined TCP / IP protocol. Tokor), IC In the bucket format of MP (Internet 'control' message 'protocol), TCP, and UDP (user datagram protocol), the first 14 bytes are the MAC layer. This is followed by a header and necessary data. ICMP is a protocol for transferring IP error messages and control messages, and is used to confirm the status of computers connected by TCP / IP. TCP is a protocol of the network transport layer. UDP is a transport layer communication protocol that does not guarantee reliability. In the packet format shown in FIG. 6, the last two bytes of the 14-byte MAC layer control information indicate the type of the bucket, from which a reference can be made by referring to the data of at least 42 bytes. The protocol type, destination IP address, port number, etc. of the packet data are understood. In other words, it can be seen that the packet data is a packet data required by the microcomputer as a function of the communication channel. In the processing flow of FIG. 5, when a reception interrupt of the packet data is received, 42 bytes of the packet data are read from the buffer memory 23 to the RAM 7 (S2). From the read data, it is determined whether or not the bucket is data addressed to its own IP address (S3). Otherwise, the packet is discarded. Discarding means that the bucket data is not read from the buffer memory 23 to the RAM 7. If it is determined in step S3 that the data is destined for its own IP address, the packet data is read from the buffer memory 23 into the RAM 7 and the protocol is analyzed (S4). According to this, a part of the received packet data in the MAC layer can be taken into the on-chip RAM 7 of the microcomputer 1 and analyzed, so that all the packet data is stored in the work area of the RAM 7. There is no need for processing to capture and deploy The size of the on-chip RAM 7 to be used can be small. Incidentally, the capacity of RAM 7 is about 2K to 4K bytes.

FIG. 7 schematically shows a state in which 42 bytes of a packet data are taken out from the buffer memory 23. The buffer memory 23 operates as a ring buffer. The packet data of the ring buffer is managed in page units. The Ethernet controller 23 has an MMU function for the RAM 7, and the CPU 2 uses this to transfer the data from the 13th byte to the 42th byte of the packet data in the page from the 13th byte to the packet data in the page. Read in the work area (TCP / IP work).

FIG. 8 illustrates details of the protocol analysis processing (S4) in FIG.

Based on the 42-byte packet data read into the RAM 7, the CPU 2 determines whether the protocol of the packet data corresponds to ARP, I CMP, TCP, UDP, or the like. In the case of ARP, an ARP reply is transmitted, and in the case of I CMP, an I CMP reply is returned. For TCP, the port number and IP address are checked, and if it is not addressed to its own address, the packet data is discarded. When it is addressed to its own address, if it is a control packet, it returns a TCP reply, and if it is a data packet, it wakes up from the event wait state. Here, to wake up from the event waiting state means to end the execution of the event waiting API program, control of the CPU 2 is shifted to the application program, and the data of the corresponding bucket data is transferred according to the application program. Part (transferred data) is transferred from the buffer memory 23 to the RAM 7. The application program performs necessary data processing on the packet data transferred to the RAM 7. According to this, the process of taking the packet data into the on-chip RAM 7 according to the result of the analysis is directly performed by the application program, and does not use the protocol stack. Therefore, professional This can contribute to the compactness of the Tocol stack. For example, the capacity of R0M6 is 32K bytes.

In the case of TCP, the occurrence of an event is recognized by protocol analysis for a packet of 42 bytes. In FIG. 8, the recognition of such an event is as follows: connection establishment (S LEV—CONNECT), connection request success, data transmission complete (S LEV—TEND), connection disconnection (SL EV—RST), and The disconnection request succeeded (SLEV_CLS). Incidentally, the data reception event (SLEV—RX) is recognized by the Rx interrupt. When the event is recognized, the CPU wakes up from the corresponding event waiting state, and shifts the processing of the CPU 2 to the application program or shifts to another API program according to the event.

Although FIG. 8 does not particularly show the processing when the UDP is recognized, it can be considered in substantially the same manner as in the case of TCP. However, it is simpler than TCP. For other protocols not supported by the system, the bucket data is discarded.

FIG. 9 shows a flow chart of the passive connection processing by TCP / IP. When the execution of the passive connection API program is specified by the application program, the API program for the passive connection setting is called from the protocol interface, and the IP address and port number of its own port are set. Then, it waits for the event of the connection establishment by executing the API waiting API program. When the event occurs, it wakes up from the event waiting state and the connection is established.

FIG. 10 illustrates a flow chart of the active connection processing by TCP / IP. When the execution of the active connection API program is specified by the application program, the API program of the active connection request is called from the protocol interface, and the IP address and port number of the partner port are set. The event is set, and then the event waiting API program is executed to wait for an event to establish a connection. When the event occurs, the computer wakes up from the event waiting state and the connection is established.

FIG. 11 illustrates a flowchart of a data transmission process by TCP / IP. Wait for event Executes the API program and waits for the occurrence of an overnight reception event. When a data reception event occurs, it wakes up from the event wait state, performs the processing described in FIG. 5 according to the application program, and stores the reception page number and data length on the Ethernet device required for transmission in the buffer memory 23. From RAM 7 Next, the process shifts to execution of the data transmission API program, and transfers the data in the RAM 7 to the buffer memory 23 to be transmitted to the Ethernet device.

FIG. 12 illustrates a flowchart of the forced disconnection for the TCP / IP connection. CPU 2 only needs to execute the API program forcibly disconnecting the connection.

FIG. 13 illustrates a flow chart of normal disconnection for the TCP / IP connection. CPU 2 executes the API program to close the connection, waits for an event, executes the API program, and waits for the occurrence of a close completion event from the connection partner. The communication by the port number is terminated due to the occurrence of the close completion event.

The invention made by the present inventor has been specifically described based on the embodiments, but the present invention is not limited thereto, and can be variously modified without departing from the gist thereof.

For example, the storage capacities of RAM and ROM are not limited to the above description and can be changed as appropriate. The term “microcomputer” is a general term for a system-on-chip semiconductor integrated circuit having a CPU. The CPU is not limited to a 16-bit CPU, but may be a 32-bit CPU or the like. From an application point of view, no specially sophisticated CPU is required. In addition, the type and processing content of the protocol processing program can be changed as appropriate. Further, the task switching when transferring a part of the bucket data from the buffer memory to the on-chip RAM is not limited to the data reception interrupt, and may be performed in response to another task switch command. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be widely applied to a TCP / IP interface in a small-scale system with relatively low data processing performance typified by network home appliances and mobile terminals.

Claims

The scope of the claims

1. A micro-computer formed on a single semiconductor chip including a central processing unit, RAM and ROM,

The ROM stores an operating system, an application program, and a TCP / IP processing program called and executed by the application program.

The TCP / IP processing program executes a connection request, an event wait,

—Having a program for evening transmission and disconnection,

The central processing unit reads a part of the bucket data into the RAM in response to the task switch command during execution of the event waiting processing program, and wakes up from the event waiting state when the bucket data is needed. The microcomputer is characterized by executing an application program and loading the corresponding bucket data into the RAM.

2. The micro computer system according to claim 1, wherein the task switch command is a data reception interrupt.

3. A microcomputer formed on a single semiconductor chip, including a central processing unit, RAM and ROM,

The RAM is used as a work area when the CPU executes a program,

The microcomputer according to claim 1, wherein the TCP / IP processing program includes a service start, connection request, event wait, data transmission, and connection disconnection processing programs.

4. The microcomputer according to claim 3, wherein the events to be waited for in the event wait are connection establishment, connection disconnection, data reception, and event wait time intervals.

5. The microcomputer according to claim 4, wherein a type of an event to be waited in the event waiting processing program is specified by the application program.

6. In response to a predetermined interrupt, the processing program waiting for the event fetches a part of the data of the bucket from the outside into the RAM, inspects the fetched data, and executes a packet requiring a corresponding packet. 6. The microcomputer according to claim 5, wherein it is determined whether or not the event has occurred, and when it is determined that the event is necessary, the event waiting state is terminated.

7. The microcontroller according to claim 6, wherein the application program fetches the data of the corresponding reception packet into the RAM in response to the end of the data reception event waiting state. Compu overnight.

8. The microcomputer according to claim 7, wherein said RAM is 2 to 4 kilobytes.

9.A process of reading a part of the packet data stored in the buffer memory of the communication device and storing it in the on-chip RAM of the microcomputer,

Inspecting the data stored in the on-chip RAM to determine whether a corresponding bucket is required; and

Storing the necessary portion of the corresponding packet data from the buffer memory in the on-chip RAM when the packet data is determined to be necessary in the determining process. Data receiving method.

10. The first process and the second process are defined by the protocol stack. 10. The data receiving method according to claim 9, wherein the third processing is specified by an application program.

11. The data receiving method according to claim 9, wherein, if the bucket data is determined to be unnecessary in the determination processing, the corresponding bucket data is discarded.

12. The data of the predetermined portion is characterized in that it is a data of 42 bytes from the 13th byte from the beginning of the bucket format in the Internet Protocol Protocol 4. 12. The data receiving method according to claim 10 or 11.