KR100247032B1 - A status change interrupt generator detecting board insertion and removal and a method thereof - Google Patents

Abstract

An apparatus for generating a state change interrupt for detecting insertion and removal of a board according to the present invention comprises: a buffer A for inputting a signal line which becomes '0' when the board is inserted and '1' when the board is removed; A buffer-B which outputs '0' when the board is mounted by connecting the output signal of the buffer A to D0 of the CPU whenever the external / read-port becomes '0'; The output of the buffer A is the input of the flip-flop D and the output of the buffer A and the output of the D flip-flop as two inputs when the read / port becomes '1'. It is connected to INT and is characterized by including XOR gate that outputs '1' when inserting and removing board.

In addition, the state change interrupt generation method for detecting the insertion and removal of the board according to the present invention includes a first step of determining whether the board is initially mounted by reading the / read-port when the CPU is initialized; A second step of not generating an interrupt by setting INT of the CPU to '0' if the board is not mounted in the first step; A third step of generating an interrupt by setting INT of the CPU to '1' if the board is mounted in the first step; A fourth step of reading / reading-port by an interrupt service routine of the CPU when an interrupt is generated; A fifth step in which the CPU executes software for board insertion by reading the / read-port and simultaneously stops the generation of an interrupt; A sixth step of generating an interrupt again when the board is removed after the interrupt has been stopped, and a seventh step of stopping the interrupt by reading the read / port by the interrupt service routine by the interrupted CPU. It is characterized by.

Description

Device and method for generating a state change interrupt that detects the insertion and removal of the board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a state change interrupt generator that detects insertion and removal of a board. In particular, a hot insertion of a board is performed by using an apparatus that generates an interrupt when a state changes. The present invention relates to a device for generating an interrupt during an operation of inserting and removing a board from a device which should be possible to enable software processing accordingly.

The communication system is composed of a central processing unit (CPU) that manages the entire system, a plurality of boards, and a backplane board for plugging the CPUs and several boards.

1 is a structural diagram of a general system including a CPU, a board, and a backplane board.

As shown, the backplane board 4 is fitted with a CPU board 1 and a plurality of boards 2 that can be attached and detached using the connector 3.

Conventionally, the CPU and the signal line are continuously observed by connecting the board and the CPU board with a signal line of a pull-up by a method of determining whether the illustrated boards 1 and 2 are inserted or removed.

2 is a structural diagram of a system including a signal line for detecting insertion and removal of a board according to the prior art.

As shown, the signal line connected to ground 6 in board 1 is pulled up by a resistor in the CPU board.

Therefore, if there is no board 1, the signal line is pulled up and read as '1' by the read port 5 in the CPU board.

When the board 1 is inserted, the signal line connected to the board 1 is connected to the ground (6), so the signal line of the CPU board is also read as '0'. Therefore, the CPU board should read the signal line periodically to check the insertion and removal of the board.

However, if the signal line is used in the above manner, the CPU reads the read port 5 periodically to see if the board is present. S / W operation that should be operated at will slow down.

In order to solve the above problems, the present invention generates an interrupt for detecting the same state change when the board is inserted and removed, thereby eliminating the CPU periodically reading a port indicating the presence of the board. It is an object of the present invention to provide an apparatus and method for generating a state change interrupt that detects insertion and removal of a board so that removal can be immediately indicated so that a quick S / W operation can be performed.

1 is a schematic diagram of a typical system including a CPU and a board and a backplane board.

2 is a structural diagram of a system including signal lines for detecting insertion and removal of a board by the prior art;

3 is a structural diagram of a system including a state change interrupt generating device.

4 is a block diagram of a state change interrupt generator according to the present invention;

<Explanation of symbols for the main parts of the drawings>

100: CPU board 200: Board 1

300 connector 400 backplane board

110: CPU 120: read port

130: pull-up resistor 140: state change interrupt generator

210: ground

141: buffer A 142: buffer B

143D flip-flop 144 XOR gate

Accordingly, the apparatus of the present invention, which is designed to achieve the above object, comprises: a buffer A for inputting a signal line which becomes '0' when the board is inserted and '1' when the board is removed; A buffer-B which outputs '0' when the board is mounted by inputting the output signal of the buffer A to the D0 of the CPU whenever the external / read-port becomes '0'; The output of the buffer A is the input of the flip-flop D and the output of the buffer A and the output of the D flip-flop as two inputs when the read / port becomes '1'. It is connected to INT and is characterized by including XOR gate that outputs '1' when inserting and removing board.

The method also includes a first step of determining whether a board is initially mounted by reading a / read-port upon initialization of the CPU; A second step of not generating an interrupt by setting INT of the CPU to '0' if the board is not mounted in the first step; A third step of generating an interrupt by setting INT of the CPU to '1' if the board is mounted in the first step; A fourth step of reading / reading-port by an interrupt service routine of the CPU when an interrupt is generated; A fifth step in which the CPU executes software for board insertion by reading the / read-port and simultaneously stops the generation of an interrupt; A sixth step of generating an interrupt again when the board is removed after the interrupt has been stopped, and a seventh step of stopping the interrupt by reading the read / port by the interrupt service routine by the interrupted CPU. It is characterized by.

According to the present invention, by using a simple read-port as shown in FIG. 2 as a state change interrupt generating device, interrupts are generated only when the board is inserted or removed in the conventional polling method. Make it possible to use the method of generating it.

3 is a structural diagram of a system including a state change interrupt generating device.

As shown, the signal line connected to the ground of the board 1 and pulled up by a resistor is connected to the CPU by the state change interrupt generator 7.

The state change interrupt generator 7 recognizes whether the board is inserted or removed by using the / read-port and generates an interrupt for the state to the CPU.

4 is a block diagram of a state change interrupt generator according to the present invention.

As shown, a buffer A 141 which is pulled up and receives a signal line which becomes '0' when the board is inserted and '1' when the board is removed; A buffer-B 142 for outputting a '0' when the board is mounted by inputting the output signal of the buffer A to the D0 of the CPU whenever the external / read-port becomes '0'; When the read / port becomes '1' with the output of the buffer A as an input, the D flip-flop 143 for outputting the corresponding input and the output of the buffer A and the output of the D flip-flop as two inputs are output. It is connected to INT of this CPU and includes XOR gate 144 that outputs '1' when the board is inserted and removed.

Hereinafter, an operation of an apparatus for generating a state change interrupt according to the present invention will be described in detail with reference to the accompanying drawings.

1. When the CPU initially initializes, it reads / read-port once to see if the board is initially mounted via DO, one of the CPU's data buses.

At this time, if the board is not mounted, the SIG-A input to the XOR gate 144 is '1', and the / read-port is always '1', so SIG-A is latched on the D flip-flop and thus SIG-B Is also '1'.

2. Then, INT, the output of the XOR gate 144, becomes '0' and the interrupt is not generated.

3. Then enable the interrupt of the CPU.

4. When the board is inserted, SIG-A, the output of buffer A 141, becomes '0'. INT becomes 1 'and interrupt occurs. The CPU then reads the / read-port from the interrupt service routine and executes a program when the board is inserted if DO is '0'.

5. As soon as the / read-port is read, SIG-B becomes' 0 'and INT becomes 0', so no interrupt is generated.

6. If the board is removed again, SIG-A becomes 1 'and INT becomes 1' and interrupt occurs.

7. When the interrupted CPU reads the / read-port, SIG-B becomes '1' and the interrupt is not generated.

The following effects can be obtained by using the present invention operated as described above.

1. It can detect the change of state by generating interrupt at the moment of change of state such as inserting and removing board.

2. CPU efficiency is high because it prevents the CPU from continuously involved such as polling.

3. It is possible to handle interrupt types that cannot be solved by using interrupt methods that recognize only one-way state changes such as ACTIVE HIGH and ACTIVE LOW.

Claims (2)

A buffer A for inputting a signal line which becomes '0' when the board is inserted and '1' when the board is removed; A buffer-B which outputs '0' when the board is mounted by inputting the output signal of the buffer A to the D0 of the CPU whenever the external / read-port becomes '0'; A flip-flop D for outputting the input when the read / port becomes '1' as the output of the buffer A; and The output of the buffer A and the output of the D flip-flop to the two inputs, the output is connected to the INT of the CPU, comprising a XOR gate for outputting a '1' when inserting and removing the board, the board A state change interrupt generator that detects insertions and removals. A first step of determining whether the board is initially mounted by reading a / read-port upon initialization of the CPU; A second step of not generating an interrupt by setting INT of the CPU to '0' if the board is not mounted in the first step; A third step of generating an interrupt by setting INT of the CPU to '1' if the board is mounted in the first step; A fourth step of reading / reading-port by an interrupt service routine of the CPU when an interrupt is generated; A fifth step in which the CPU executes software for board insertion by reading the / read-port and simultaneously stops the generation of an interrupt; A sixth step of generating an interrupt again when the board is removed after the interruption has been stopped; and And a seventh step in which the interrupted CPU stops generating an interrupt by reading a / read-port by an interrupt service routine.

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