KR950001513B1 - Acknowledgement transmission method in data link layer of mini-map network - Google Patents

Abstract

When the network system receives acknowledgment request data frame in the data link layer of Mini-MAP network, the method sends acknowledgment quickly to increase system efficiency. Mini-MAP network board consists of a micro-controller (10), a system ROM (12) loading system software, a non-volatile RAM (14), a token-bus controller (16), a dynamic RAM controller (18), a system RAM (20), a dual-port RAM (22), a modem (24) and an arbitration logic (26). Micro-controller consists of a micro-processor, a clock generator, a DMA controller, a timer and etc.

Description

How to send an acknowledgment at the data link layer of a Mini-MAP network

1 is a block diagram showing the configuration of a minimap network interface board for carrying out the present invention.

2 is a flowchart illustrating an initialization process of a token bus controller according to the present invention;

3 is a flowchart illustrating a process of transmitting an arrival notification of the present invention.

* Explanation of symbols for main parts of the drawings

10 microcontroller 12 system ROM

14 Inactive RAM 16 Token Bus Controller

18: Dynamic RAM Controller 20: System RAM

22: dual port RAM 24: modem

The present invention provides an arrival notification required connectionless service which is a type 3 service among data link layer services of a mini-MAP network system, which is a network for factory automation. The present invention relates to a method for constructing an acknowledgment frame of a data frame when an acknowledgment data frame is received from a station on the network and sending the received acknowledgment frame.

In the minimap specification, the size of the slot time, which specifies the transmission of this arrival notification frame within 3 slot times, is determined by the designer in consideration of the worst case during the network design process.

During the network operation, the network is idle because no station can transmit it on the network of other data frames during the time interval between sending an arrival notification required data frame and receiving an arrival notification frame. .

Therefore, the longer the slot time, the lower the efficiency of the network. In the minimap network, it is very important to make the arrival notification as fast as possible.

The conventional method of transmitting an arrival notification frame reads an interrupt state word in a unique memory area of a token bus controller when an interrupt is generated by receiving an arrival notification required data frame. To check whether or not interrupt occurs (RXRWR bit, the 15th bit of interrupt status word 0 is set to 1 in case of interruption), and configure and send the arrival notification frame for the received arrival notification data frame. It was.

This conventional method is time consuming to construct the arrival notification frame, and since the interrupt status word indicates the occurrence of 31 events, it is also time consuming to check all of these and provide necessary services. Therefore, there was a problem that the transmission of the arrival notification frame is delayed.

Accordingly, an object of the present invention is to increase the efficiency of use of a network system by enabling a quick acknowledgment when an arrival notification data frame is received at a data link layer of a minimap network system.

In order to achieve the above object, the present invention allows the pre-writable part of the arrival notification frame to be written before initializing the token bus controller, and only the variable part is created during network operation, and the arrival notification frame during interrupt service. Only writes and transfers are performed within the service routine and the remaining 30 events are later processed outside of the interrupt service routine.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 is a block diagram of a minimap network interface board for carrying out the present invention.

In the drawing, reference numeral 10 denotes a microcontroller, which is composed of a microprocessor, a clock generator, a direct memory access (DMA) controller, a timer or counter, memory, peripheral circuit selection logic, and the like. It has a function to control peripheral hardware such as I / O control. Reference numeral 12 denotes a system ROM, which contains software required for operating the system.

Reference numeral 14 is a nonvolatile RAM, 16 is a token bus controller (MC 68824), 18 is a dynamic RAM controller, 20 is a system RAM, 22 is a dual port RAM, 24 is a modem, and 26 is a bus arbitration logic. will be.

The system RAM 20 stores data necessary for operating the system, which is shared between the microcontroller 10 and the token bus controller 16.

The token bus controller 16 and the modem 24 perform the functions of the transmission medium access control (MAC) sublayer and the physical layer of the minimap, and transmit data to the transmission medium at the request of the microcontroller 10. The signal received from the transmission medium is transformed into a data form that can be processed by the microcontroller 10.

The bus arbitration logic 26 consists of circuits that arbitrate the usage rights of the system bus between the microcontroller 10 and the token bus controller 16.

The arrival notification transmission process of the present invention performed by the mini-map network interface board outlined above will be described with reference to FIGS. 2 and 3.

2 is a flowchart illustrating an initialization process of the token bus controller according to the present invention. First, as the intrinsic memory of the token bus controller required to construct the arrival notification frame, memory for the frame descriptor required by the token bus controller 16, memory for the buffer descriptor, and data buffer Allocates system RAM 20 as classified as memory; (S1)

Subsequently, except for the destination station address, which is a variable part of the contents of the arrival notification frame, and the status information field 1hyte according to the arrival notification frame reception, the remaining parts are recorded in advance (S2).

When the preconfiguration of the arrival notification frame is completed in this manner, the address of the arrival notification frame is recorded at positions 84H and 88H in the initialization table of the token bus controller 16; (S3)

In this way, when the token bus controller 16 receives the arrival notification required data frame, the destination station address in the arrival notification frame is automatically recorded.

Therefore, it is only necessary to record the status information according to the receipt of the arrival notification required data during network operation. When the initialization related to the configuration of the arrival notification frame is completed, an initial value is set in an interrupt mask; (S4)

At this time, the RXRWR and TP bits are set to 1 in an interrupt mask which is an offset AAH of the token bus controller initialization table.

In the present invention, an interrupt mask is generated so that an interrupt is generated only upon receipt of a data frame (RXRWR bit) and token transfer (TP: a plurality of data frames are completed). By setting the initial value of, it improves the network communication processing ability due to frequent interrupt occurrence.

Then complete the rest of the tokenbus controller initialization table; (S5) After the token bus controller 16 is initialized according to the token bus controller initialization table, the operation mode of the token bus controller 16 is set in a non-temporary response mode (not to allow the token bus controller 16 to operate in accordance with the minimap standard). in predefined response mode); (S6, S7)

When the initialization process of the tokenbus controller described above is completed, the tokenbus controller 16 performs a normal data transmission / reception service; (S8)

3 is a flowchart illustrating a process of transmitting an arrival notification according to the present invention and a service routine performed when an interrupt is generated by the token bus controller 16.

First, the microcontroller 10 reads the interrupt status word from the unique memory area of the token bus controller 16 and then checks that the RXRWR of the interrupt mask is used to check whether the token bus controller 16 has received an arrival notification required data frame. Determine whether the bit is set to '1'; (S10, S11)

At this time, when the arrival notification required data frame is received, that is, when the RXRWR bit is set to '1', the memory address pointer of the received arrival notification required data frame in the unique memory area of the token bus controller 16 is measured. reads the address pointer value, checks the suitability of the received data frame type, destination, sequence number, etc. and writes the status information according to the result of the check, and initializes the preconfigured arrival notification before initializing the token bus controller 16. Gives a response ready command to the tokenbus controller 16 after writing to the frame; (S12 to S15)

If the RXRWR bit is not set to '1' (i.e., no at step S11) or if all of the above mentioned steps S12 to S15 have been performed, interrupt the interrupt status word containing information on other important events. It sends a message to the processing routine in the normal state instead of the state, clears all interrupt status words of the token bus controller's unique memory area to '0', and terminates the interrupt service; (S16, 17)

When an interrupt occurs due to a cause other than the receipt of an arrival notification data frame, only the status word is transferred to the normal processing routine and the interrupt service is terminated.

As described above, according to the present invention, when the arrival notification required data frame is received, the arrival notification (acknowledgement) is quickly transmitted, thereby reducing the time for which the minimap network is in the idle state, thereby increasing the use efficiency of the network.

Claims (4)

A microcontroller 10 that handles at least an interrupt, controls input and output of data, and controls peripheral hardware, and transmits data to or transmits a signal received from the transmission medium in response to a request of the microcontroller 10; A token controller 16 and a modem 24 which perform functions of the minimap transmission medium access control layer and the minimap transmission medium access physical layer, which the microcontroller 10 converts into data that can be processed; In the minimap network system including the system RAM 20, which is shared by the token bus controller 16 and the token bus controller 16, and stores the data required for operating the system, it is determined whether an interrupt occurs according to the reception of the arrival notification required data frame. Configure an arrival notification frame for the received arrival notification required data frame A method for transmission; A first step for initialization required to construct an arrival notification frame, and a second step of setting an initial value in an interrupt mask of the token bus controller initialization table; Setting other partial values of the token bus controller initialization table; After initializing the token bus controller 16 according to the token bus controller initialization table, the operation mode of the token bus controller 16 is set in a non-temporary response mode so that the token bus controller 16 operates according to the minimap standard. A fourth step of allowing the token bus controller 16 to perform a normal transceiving service; After the microcontroller 10 reads the interrupt status word from the unique memory area of the tokenbus controller 16, the RXRWR bit is checked to see whether the tokenbus controller 916 received the arrival notification required data frame. A fifth step of determining whether is set to '1'; When the RXRWR bit is set to '1', the pointer value is read from the intrinsic memory area of the token bus controller 16 to check the suitability of the received data and receive the data according to the result of the conformance check. A sixth step of recording status information in the arrival notification frame and delivering a response ready command to the token bus controller 16; When the RXRWR bit is not set to '1' or when the sixth step is completed, the interrupt status word is transmitted as a message to an interrupt status processing task operating in a normal state and the unique memory of the token bus controller 16 is transmitted. And a seventh step of terminating the interrupt service after clearing the interrupt status word of the region to " 0 ". 2. The method of claim 1, wherein the first step includes allocating the system RAM 20 for the unique memory area of the token bus controller 16 necessary for constructing the arrival notification frame, Recording a pre-writable portion and recording an address of the arrival notification frame at positions 84H and 88H in the token bus controller initialization table. How to send arrival notification. The method of claim 2, wherein the initial value of the interrupt mask is set such that an interrupt is generated only upon receipt of the arrival notification required data frame and upon token delivery. Way. 4. The method of claim 1 or 3, wherein the RXRWR bit and the TP bit are set to '1' in the interrupt mask of the token bus controller initialization table.