KR0150233B1 - Bus occupation arbitration apparatus in common bus - Google Patents

Abstract

The present invention relates to an electronic exchange system, and uses a virtual occupancy signal in a system for transmitting and receiving data through a shared bus shared by a plurality of nodes. Minimizing the utilization of the bus to maximize the use.

The present invention provides a common bus synchronous clock generating means for generating a synchronous clock for bus arbitration of all nodes connected on a common bus, a frame synchronous signal generating means for generating a synchronous signal for initializing the arbitration counter means, and each node. The arbitration counter means for generating a bus occupancy permission signal (Pre-AST) and a bus occupying signal (AST) to transmit data through the occupied public bus. A first virtual occupancy generating means for generating a virtual occupancy signal (V-AST) for procuring the arbitration counter means, and a virtual occupancy signal for occupying the bus in the next order during data transfer by occupying the bus; And a second virtual occupation signal generating means for generating a.

Description

Bus occupancy arbitration device on public bus

1 is a block diagram of a conventional bus occupancy arbiter.

2 is a timing diagram of an embodiment of conventional bus occupancy.

3 is a block diagram of a bus occupancy arbitration apparatus in a public bus according to the present invention.

4 is a timing diagram of an embodiment of the present invention shown in FIG.

* Explanation of symbols for main parts of the drawings

10,100: Master

11,110: Shared bus synchronous clock generator

12,120: frame synchronization signal generator

13: first virtual occupation signal generator

20,200: Node 21,210: Arbitration Counter

22,220: bus occupancy determination unit 23: second virtual occupancy signal generation unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic exchange system. In particular, in a system for transmitting and receiving data through a shared bus shared by a plurality of nodes, another node occupies the bus again after using a bus of one node using a virtual occupancy signal. The present invention relates to a bus occupancy arbitration apparatus in a public bus that minimizes the time required to maximize the utilization of the bus.

In the related art, as shown in FIG. 1, the common bus synchronous clock generator 110 and the frame synchronous signal generator 120 are provided on the master 100 side, and an arbitration counter (node) is provided on the node 200 side. 210 and the bus occupancy determination unit 220, the common bus synchronous clock generation unit 110 generates a common bus synchronous clock (ASTCLK), which is a synchronous clock for bus arbitration of all the nodes present on the bus, The frame synchronizing signal generator 120 generates a frame synchronizing signal FRS for initializing the arbitration counter 210 located in each node 200. The arbitration counter 210 is initialized to the arbitration address applied according to the frame synchronization signal FRS applied from the frame synchronization signal generator 120 of the master 100 and counted by the applied common bus synchronization clock ASTCLK. When the process proceeds to have a specific value, the bus occupancy determination unit 220 applies a bus occupancy permission signal Pre-AST. The bus occupancy determining unit 220 outputs the bus occupancy signal AST when the data to be transmitted from the outside is applied while the bus occupancy permission signal Pre-AST is applied from the arbitration counter 210, and then occupies the common bus. To transfer the data.

The operation of the conventional bus occupancy arbitration apparatus configured as described above will be described with reference to FIG. For example, there are two nodes. The arbitration address of the first node is set to 0x04, the arbitration address of the second node is set to 0x0d, and the arbitration counter 210 provided in each node is occupied by the bus. Assume that a permission signal (Pre-AST) is generated. First, as shown in the timing diagram of FIG. 2, when the frame synchronizing signal generator 120 of the master 100 generates the frame synchronizing signal FRS, the arbitration counter 210 of each node is assigned to each node. As the arbitration address is initialized, the arbitration counter 210 of the first node is initialized to 0x04 and the arbitration counter 210 of the second node is initialized to 0x0d. Thereafter, the arbitration counter 210 of each node performs a counter according to the common bus synchronous clock (ASTCLK) applied from the common bus synchronous clock generator 110. Therefore, after two cycles of the common bus synchronous clock ASTCLK has elapsed, the value counted by the arbitration counter 210 of the second node having the arbitration address of 0x0d becomes 0x0f, so that the arbitration counter of the second node ( 210 generates a bus occupancy permission signal Pre-AST and applies it to the bus occupancy determination unit 220 of the second node. Accordingly, when there is data to be transmitted, the bus occupancy determining unit 220 of the second node generates a bus occupancy signal AST on the public bus to occupy the public bus and transmit data. At this time, the arbitration counter 210 of the first node having an arbitration address of 0x04 receives a bus occupancy signal AST from the bus occupancy determining unit 220 of the second node and stops counting. The arbitration counter 210 value is 0x06 because two cycles of the shared bus synchronous clock (ASTCLK) have passed. Subsequently, when the data transmission of the second node is terminated, the bus occupancy determination unit 220 of the second node releases the bus occupancy signal AST generated by the shared bus. Accordingly, the arbitration counter 210 of the first node is released. ) Continues counting from the count value of 0x06.After the 10-cycle common bus synchronous clock (ASTCLK) has elapsed after releasing the shared bus of the second node, the arbitration counter 210 of the first node has passed. Since the value counted at 0x0f, the arbitration counter 210 of the first node generates a bus occupancy permission signal (Pre-AST) and applies it to the bus occupancy determination unit 220 of the first node. If there is data to be transmitted, the bus occupancy determining unit 220 generates a bus occupancy signal AST on the public bus and transmits the data by occupying the public bus.

As described above, when one node occupies the public bus, the arbitration counter of the other node stops counting. After the node currently occupying the public bus stops occupying the public bus, the next node stops the public bus. Until occupying, since a predetermined number of common bus synchronous clocks (ASTCLK) have elapsed or the public bus can be occupied, data transmission takes a long time and there is a problem in that the public bus cannot be used efficiently.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to minimize the delay between the completion of data transmission by one node occupying the public bus and the utilization of the bus by minimizing the delay time until the next node occupies the public bus. It is utilized to the maximum and to shorten the transmission time of data.

The present invention for achieving the above object is a system having a master and a plurality of nodes for transmitting and receiving data through a public bus, the synchronization clock for bus arbitration of all nodes connected on the public bus (ASTCLK) And a common bus synchronizing clock generating means for generating a frame synchronizing signal (FRS) when a predetermined count value is counted according to the synchronizing clock (ASTCLK) applied from the common bus synchronizing clock generating means. Frame synchronization signal generating means for first outputting a pre-FRS and generating a pause when the virtual occupancy signal V-AST is applied; When the frame synchronizing signal FRS is applied from the synchronizing signal generating unit, the frame synchronizing signal FRS is initialized to the arbitration address preset for each node. The bus occupancy permission signal (Pre-AST) is generated when the arbitration address reaches a predetermined value by counting according to the common bus synchronizing clock (ASTCLK) applied from the bus synchronizing clock generating means, but the virtual occupancy signal (V-AST) An arbitration counter means for pausing the count when is applied to the node, and each node is provided with a bus occupancy permission signal (PrE-AST) and a virtual occupancy signal (V-AST) is applied from the arbitration counter means. And bus occupancy determining means for generating a bus occupancy signal (AST) and transmitting data over the occupied public bus if there is no node currently occupying the common bus and transmitting data. When the signal Pre-FRS is applied, if a node occupying the current public bus and transmitting data exists, a virtual occupancy signal V-AST is generated to generate a car of the frame synchronization signal generating means. A first virtual occupancy signal generating means for stopping a count operation and a counting operation of the arbitration counter means; and each node is provided in each node and has data to be transmitted to a public bus and a bus occupancy permission signal from the arbitration counter means (Pre-AST). And a second virtual occupancy signal generating means for generating a virtual occupancy signal (V-AST) that occupies the public bus in the next order when there is another node occupying the public bus when the current is applied. Provides a bus occupancy arbitrator in

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a block diagram of a bus occupancy arbitration apparatus in a public bus according to the present invention, and FIG. 4 is a timing diagram of an embodiment of the present invention shown in FIG.

As can be seen in FIG. 3, the present invention provides a master 10 having a common bus synchronization clock generator 11, a plane synchronization signal generator 12, and a first virtual occupation signal generator 13, and arbitration. It consists of the node 20 provided with the counter 21, the bus occupancy determination part 22, and the 2nd virtual occupation signal generation part 23. As shown in FIG. The common bus synchronous clock generator 11 generates a common bus synchronous clock (ASTCLK) for bus arbitration of all nodes connected on the public bus. The frame synchronizing signal generating unit 12 counts according to the common bus synchronizing clock ASTCLK applied from the common bus synchronizing clock generating unit 11 and generates a frame synchronizing signal FRS when a predetermined count is reached. Before generating the synchronization signal FRS, a pre-FRS is generated and applied to the first virtual occupation signal generator 13, and the count is paused when the virtual occupation signal V-AST is applied. do. The first virtual occupancy signal generation unit 13, when the pre-synchronization signal (Pre-FRS) is applied from the frame synchronization signal generation unit 12, virtual occupancy if there is a node currently occupying the common bus and transmitting data The signal V-AST is generated to stop the count operation of the frame synchronization signal generator 12 and the count operation of the arbitration counter 21. The arbitration counter 21 is provided at each node. When the frame synchronization signal generation unit 12 receives the frame synchronization signal FRS, the arbitration counter 21 initializes the arbitration address preset for each node and then uses the shared address. When the arbitration address reaches a predetermined value by counting according to the common bus sync clock (ASTCLK) applied from the bus sync clock generator 11, a bus occupancy permission signal (Pre-AST) is generated. If the AST) is applied, the count is paused. The bus occupancy determining unit 22 is provided at each node, and a bus occupancy permission signal Pre-AST is applied from the arbitration counter 21 or a virtual occupancy signal V-AST is applied. If there is no node currently occupying a public bus and there is data to be transmitted, a bus occupancy signal (AST) is generated to transmit data through the occupied public bus. The second virtual occupancy signal generator 23 is provided in each node and occupies the current public bus when there is data to be transmitted to the public bus and a bus occupancy permission signal (Pre-AST) is applied from the arbitration counter 21. If another node exists, a virtual occupancy signal (V-AST) is generated to occupy the public bus in the following order.

Referring to the operation of the present invention configured as described above are as follows. In the embodiment of the present invention, there are two nodes, and upon initialization of the arbitration counter 21 provided in each node by the frame synchronization signal FRS applied from the frame synchronization signal generation unit 12, the arbitration counter of the first node is present. (21) is initialized with an arbitration address of 0x04, the arbitration counter 21 of the second node is initialized with an arbitration address of 0x0d, and the arbitration address counted by the arbitration counter 21 of each node is 0x0f. It is assumed that each arbitration counter 21 generates a bus occupancy permission signal (Pre-AST). First, as shown in the timing diagram of FIG. 4, when the frame synchronizing signal generator 12 of the master 10 generates the frame synchronizing signal FRS, the arbitration counter 21 of each node is assigned to each node. As the arbitration address is initialized, the arbitration counter 21 of the first node is initialized to 0x04 and the arbitration counter 21 of the second node is initialized to 0x0d. Thereafter, the arbitration counter 21 of each node counts according to the common bus synchronous clock ASTCLK applied from the common bus synchronous clock generator 11. Therefore, after two cycles of the common bus synchronous clock ASTCLK has elapsed, the value counted by the arbitration counter 21 of the second node having the arbitration address of 0x0d becomes 0x0f, so that the arbitration counter of the second node ( 21 generates a bus occupancy permission signal Pre-AST and applies it to the bus occupancy determination section 22 and the second virtual occupancy signal generation section 23 of the second node. Accordingly, when there is data to be transmitted, the bus occupancy determining unit 22 of the second node occupies the public bus and transmits data while generating a bus occupancy signal AST on the public bus. At this time, the arbitration counter 21 of the first node having the arbitration address of 0x04 continues to count without stopping the count even when the bus occupation signal AST is received from the bus occupation determining unit 22 of the second node. After 10 nodes of common bus synchronous clock (ASTCLK) has elapsed after two nodes occupy the bus, the value counted by the arbitration counter 21 of the first node with arbitration address 0x04 becomes 0x0f. The arbitration counter 21 generates a bus occupancy permission signal Pre-AST and applies it to the bus occupancy determination section 22 and the second virtual occupancy signal generation section 23 of the first node. At this time. The second virtual occupancy signal generator 23 of the first node recognizes that a specific node (second node in the present embodiment) occupies the bus since the bus occupancy signal AST is generated on the public bus. Since the bus occupancy permission signal (Pre-AST) is generated at the arbitration counter 21 of the first node and there is data to be transmitted, a virtual occupancy signal (V-AST) that the first node occupies the public bus is next to the public bus. As a result, the frame synchronization signal generator 12 and the arbitration counter 21 of the first node and the second node pause the count.

On the other hand, when the data transfer of the second node is terminated, the bus occupancy determining unit 22 of the second node releases the bus occupancy signal AST generated by the shared bus. At this time, the bus occupancy determining unit 22 of the first node is released. Since the virtual occupancy signal (V-AST) is generated from the second virtual occupancy signal generator 23 of the first node, the bus occupancy signal (AST) is a common bus to the common bus synchronous clock (ASTCLK) of the next cycle. To occupy the public bus and transmit data. At this time, the second virtual occupation signal generator 23 of the first node releases the virtual occupation signal V-AST. Therefore, after the second node has finished occupying the bus, it takes one cycle of the common bus synchronous clock ASTCLK until the first node occupies the bus.

On the other hand, when the last node occupies the public bus in the process of transmitting data in the same manner as described above, the frame synchronization signal generator 12 is not applied to the virtual occupancy signal (V-AST) The counting signal is continuously counted according to the pre-synchronization signal (Pre-) to the first occupancy signal generator (13) before generating the frame synchronization signal (FRS) indicating the last node by checking the count value and informing the restart of the turn cycle. FRS). Accordingly, the first virtual occupancy signal generator 13 receives a pre-FRS signal from the frame sync signal generator 12, thereby checking whether there is a node occupying the common bus and transmitting data. F. Since the last node is currently transmitting data by occupying the common bus, a virtual occupancy signal (V-SAT) is generated to perform the count operation of the frame synchronization signal generator 12 and the count operation of the arbitration counter 21. Stop it. This is because when the last node occupies the public bus and transmits data, another node does not generate the virtual occupancy signal (V-AST) from the second virtual occupancy signal generator 23 because its own bus occupied order has already passed. Do not. Therefore, since the counter in the frame synchronizing signal generator 12 and the arbitration counter 21 of each node continue to count, the frame synchronizing signal generator 12 generates a frame synchronizing signal FRS indicating restart of the turn cycle. This is to prevent the phenomenon that the arbitration counter 21 of each node is initialized in the state where the last node does not end the data transmission due to the occurrence.

As described above, in the present invention, when a particular node occupies a common bus shared by a plurality of nodes, when a specific node transmits and receives data, an arbitration counter of another node continues to count and uses a bus of one node by using a virtual occupancy signal. Later, minimizing the time until another node occupies the bus minimizes the utilization of the bus and ensures the speed of data transfer.

Claims (1)

A system comprising a master and a plurality of nodes for transmitting and receiving data through a public bus, the public bus synchronous clock generating means for generating a synchronous clock (ASTCLK) for bus arbitration of all nodes connected on the public bus; The frame synchronization signal FRS is generated when the count value is determined according to the synchronization clock ASTCLK applied from the common bus synchronization clock generating means, and the frame synchronization signal FRS is generated before the frame synchronization signal FRS is generated. Frame synchronizing signal generating means for outputting the FRS first and stopping the count when the virtual occupation signal V-AST is applied; and at each node, the frame synchronizing signal FRS is provided from the frame synchronizing signal generating means. ) Is initialized to the arbitration address preset for each node, and then authorized from the common bus synchronous clock generating means. Arbitration that counts according to the common bus synchronous clock (ASTCLK) and generates a bus occupancy permission signal (Pre-AST) when the arbitration address reaches a predetermined value, but pauses the count when the virtual occupancy signal (V-AST) is applied. Counter means: Each node provided in each node, the node occupying the current public bus in the state that the bus occupancy permission signal (Pre-AST) is applied or the virtual occupancy signal (V-AST) is applied from the arbitration counter means; Bus occupancy determination means for generating a bus occupancy signal (AST) and transmitting data over the occupied public bus if there is data to be transmitted; and when a pre-sync signal (Pre-FRS) is applied from the frame synchronizing signal generating means. If there is a node currently occupying a common bus and transmitting data, a virtual occupancy signal (V-AST) is generated to generate a count operation of the frame synchronization signal generating means and a count of the arbitration counter means. A first virtual occupancy signal generating means for stopping the network operation; each node is provided with each node and occupies the current public bus when there is data to be transmitted to the public bus and a bus occupancy permission signal (Pre-AST) is applied from the arbitration counter means. And a second virtual occupancy signal generating means for generating a virtual occupancy signal (V-AST) to occupy the public bus in the next sequence when another node is present.