JPH05158718A - Integrated circuit - Google Patents

Abstract

PURPOSE:To share a peripheral circuit serving as an integrated circuit in accordance with the switching of software and without deteriorating the processing ability of a microcomputer device. CONSTITUTION:A peripheral circuit 7 and its control circuit 1 constitute an integrated circuit 10. The circuit 1 consists of the instruction register circuits 4 and 5 which hold the external operating instructions, a selector circuit 6 which transmits the outputs of both circuits 4 and 5, a write selection control circuit 3 which selectively controls the circuits 4, 5 and 6, and a switching instruction register circuit 2 which gives an output to the circuit 3 in response to an external switching instruction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit, and more particularly to an integrated circuit of peripheral circuits constituting a microcomputer device.

[0002]

2. Description of the Related Art Generally, an integrated circuit forming a peripheral circuit used in a microcomputer device is provided to simplify hardware and software.

For example, programmable timer circuits are used to determine software timing and interrupt control circuits are used to execute complex interrupt sequences.

In recent years, with the increase in speed of microcomputer devices, there has been a strong demand for a system in which a single microcomputer can simultaneously operate a plurality of software and can be used by a plurality of users at the same time.

In order for one microcomputer to operate a plurality of software at the same time, it is necessary to perform a time-divisional operation of switching software at regular time intervals. This time division operation is activated by an interrupt generated when the state of a timer circuit outside or inside the microcomputer changes. When this interrupt occurs, it is necessary to save the internal register of the microcomputer and the state on the main memory, so it is important to reduce the time required for this switching.

[0006]

Since the above-mentioned conventional integrated circuit is not made on the assumption that a plurality of software is simultaneously operated by one microcomputer, the time-division operation for switching the software at every fixed time is performed. In order to share the peripheral circuits in the system that performs the interrupt processing and the system that performs the interrupt processing, it is necessary to read the current operating state and internal state from the inside of the peripheral circuit and save them.

Further, in an integrated circuit which cannot read the internal state, it is necessary to prohibit its use during interrupt processing, so that there is a limitation that the peripheral circuit cannot be shared by software.

As described above, the microcomputer has a drawback in that the processing capacity of the system is lowered because the microcomputer has to perform extra processing.

[0009]

In order to solve the above-mentioned drawbacks of the prior art, the integrated circuit of the present invention receives a command to change the internal operating state and a control command from the outside. In an integrated circuit formed of a control circuit for outputting to the controlled circuit, the control circuit holds a plurality of instruction register circuits for holding an operation instruction from the outside, and the output of the instruction register circuit is controlled by the controlled circuit. A selector circuit for sending to the circuit, a write selection control circuit for controlling write selection to the plurality of instruction register circuits and output selection of the selector circuit, and output to the write selection control circuit according to a switching instruction from the outside. And a switching instruction register circuit, and
The control circuit includes an up-down counter circuit connected to an instruction register circuit and outputting to a write selection control circuit, and further, the control circuit is controlled by a write selection control circuit output and connected to a controlled circuit. And a plurality of operating state register circuits for holding the operating state signals.

[0010]

The switching instruction register circuit outputs to the write selection control circuit in response to a switching instruction from the outside, and the write selection control circuit controls the writing selection to the plurality of instruction register circuits and the output selection of the selector circuit by the output. Then, the peripheral circuit as the controlled circuit is controlled based on the selected output content.

[0011]

EXAMPLE Next, an example of the present invention will be described with reference to FIG.

FIG. 1 is a block diagram of an essential part of the integrated circuit of the first embodiment.

The integrated circuit 10 of this embodiment includes a controlled circuit 7 which is a peripheral circuit, two instruction register circuits 4 and 5, an instruction register circuit 5, a selector circuit 6 for selecting the output of each instruction register circuit, and a switching instruction register. The control circuit 1 includes a circuit 2 and a write selection control circuit 3 that controls them.

The control circuit 1 is a control circuit for sending a control command received from the outside to the controlled circuit 7.

The switching instruction register circuit 2 is a circuit for holding a switching instruction received from the outside.

The write selection control circuit 3 is a control circuit for performing a write operation to the instruction register circuit indicated by the switching instruction register circuit 2.

The instruction register circuit 4 is a first register circuit that holds an instruction for the controlled circuit 7.

The instruction register circuit 5 is a second register circuit that holds an instruction for the controlled circuit 7.

The selector circuit 6 selects the output of either the instruction register circuit 4 or the instruction register circuit 5,
It is a selection circuit for sending to the controlled circuit 7.

The controlled circuit 7 is a peripheral circuit which is controlled by the control circuit 1 and is in the integrated circuit 10.

The feature of the present invention resides in that a control function for instantaneously switching a plurality of instructions by controlling a plurality of instruction register circuits and a selector circuit in FIG. 1 by a switching instruction register circuit and a write selection control circuit is provided. It is in the control circuit 1.

First, it is assumed that the present integrated circuit 10 is connected to a microcomputer device (hereinafter abbreviated as MPU) and the instruction register 4 is selected as an initial state.

First, a normal instruction writing operation will be described.

The MPU writes an operation command to the integrated circuit 10 in order to determine the operation state, and then writes the operation data.
And the write control signal 101 is changed.

The write selection control circuit 3 writes the write signal 31 of the instruction register circuit 4 selected in the initial state.
Is changed and the operation command of the write data signal 102 is written and held in the instruction register circuit 4.

The operation command held in the command register circuit 4 is input to the selector circuit 6 as a command output signal 41.

The selector circuit 6 is a write selection control circuit 3
Command output signal 41 according to selection signal 33 output by
Is sent to the controlled circuit 7 as a command output signal 61.

Upon receiving the command output signal 61, the controlled circuit 7 changes its internal operation according to the command.

Since the operation instruction written in the normal state is held in the instruction register circuit 4, the controlled circuit 7 performs the operation according to the instruction.

Next, the operation when the present integrated circuit 10 is used when the MPU is operating a plurality of software in a time division manner will be described.

When the software is switched, the MPU needs to switch the instruction to the integrated circuit in order to use the integrated circuit 10 in the switched software.

First, the MPU sends the switching command data of the command register circuit to the switching command register circuit 2 as the write data signal 102 and changes the write control signal 101.

The switching instruction register circuit 2 holds the switching instruction data and sends it as the switching instruction signal 21 to the write selection control circuit 3.

The write selection control circuit 3 receives the switching instruction signal 21, recognizes that the instruction is for the instruction register circuit 5, and sets the selection signal 33 to receive the output from the instruction register circuit 5.

Further, the MPU sends an operation command to the write data signal 102 and changes the write control signal 101 in order to determine the operation state to the integrated circuit 10. The write selection control circuit 3 changes the write signal 32 of the instruction register circuit 5 selected by the data written in the switching instruction register circuit 2, and causes the instruction register circuit 5 to hold the operation instruction of the write data signal 102. ..

The operation command held in the command register circuit 5 is input to the selector circuit 6 as a command output signal 51.

The selector circuit 6 is a write selection control circuit 3
Command output signal 51 according to selection signal 33 output by
Is sent to the controlled circuit 7 as a command output signal 61.

Upon receiving the command output signal 61, the controlled circuit 7 changes its internal operation according to the operation command.

Since the operation instruction written in the state where the software is switched in this way is held in the instruction register circuit 5, the controlled circuit 7 performs the operation according to the instruction.

Next, the operation of the MPU for returning the operation of the integrated circuit 10 to the state before the switching in order to return the control to the original software again after the execution of the switched software is completed will be described.

The MPU sends the switching command data of the command register circuit to the switching command register circuit 2 as the write data signal 102, and at the same time, the write control signal 10
Change 1

The switching command register circuit 2 holds the switching command data and sends it as the switching command signal 21 to the write selection control circuit 3.

The write selection control circuit 3 receives the switching instruction signal 21, recognizes that the instruction is for the instruction register circuit 4, and sets the selection signal 33 to receive the output from the instruction register circuit 4. .. As a result, the instruction register 4 returns to the selected initial state.

After this operation, the operating state can be switched by writing a switching command to the switching command register circuit 2.

FIG. 2 is a block diagram of essential parts of an integrated circuit of the second embodiment.

The integrated circuit 10 of the present embodiment includes the controlled circuit 7
And a plurality of instruction register circuits 4 to 9
And a selector circuit 6 for selecting the output of each instruction register circuit
And a switching instruction register circuit 2, an up / down counter circuit 8 and a control circuit 1 composed of a write selection control circuit 3 for controlling them.

A feature of the present invention is that an operation of instantly switching a plurality of instructions by controlling a plurality of instruction register circuits and a selector circuit in FIG. 2 by a switching instruction register circuit, an up / down counter circuit and a write selection control circuit. This is because the control circuit has a control function for performing.

First, in the initial state, the up / down counter circuit 8 shows a value of 0 as the counter output 81. At this time, the instruction register circuit 4 is selected as the instruction register.

When the counter output 81 of the up / down counter circuit 8 increases to 1, 2, 3, ..., N-1, the write selection control circuit 3 causes the corresponding instruction register circuits 5 ,. Is selected.

The MPU issues a PUSH instruction to the integrated circuit 10 when switching software or performing interrupt processing, and issues a POP instruction when returning the processing.

The integrated circuit 10 includes a switching instruction and PUSH.
The PUSH instruction increments the up / down counter circuit 8 by +1 and the POP instruction up / down counter circuit 8 by -1 by recognizing the instruction and the POP instruction.

The fact that the instruction register circuit is saved and the instruction register circuit is restored by issuing these instructions to control the operating state of the controlled circuit 7 is similar to the operation of the embodiment of FIG. To do.

FIG. 3 is a block diagram of essential parts of an integrated circuit of the third embodiment.

The integrated circuit 10 of the present embodiment includes the controlled circuit 7
And a plurality of instruction register circuits 4 to 9
And a selector circuit 6 for selecting the output of each instruction register circuit
And a switching instruction register circuit 2, an up / down counter circuit 8, an operation state register circuit 11 and an operation state register circuit 16, and a control circuit 1 constituted by a write selection control circuit 3 for controlling them.

A feature of the present invention is that a plurality of instruction register circuits, an operation state register circuit, and a selector circuit in FIG. Also, the control circuit has a control function for performing an operation of instantaneously switching the operating state.

First, in the initial state, the up / down counter circuit 8 shows a value of 0 as the counter output 81, and the instruction register circuit 2 is selected as the instruction register at this time.

When the counter output 81 of the up / down counter circuit 8 increases to 1, 2, 3, ..., N-1, the write selection control circuit 3 causes the corresponding instruction register circuits 5 ,. Is selected.

The MPU issues a PUSH instruction to the integrated circuit 10 when switching software or performing interrupt processing, and issues a POP instruction when returning the processing.

The integrated circuit 10 includes a switching instruction and PUSH.
Recognize commands and POP commands. First, the PUSH instruction saves the current operating state signal 71 of the controlled circuit 7 to the operating state register circuit selected by the up / down counter circuit, and increments the up / down counter circuit 8 by 1. Further, the POP instruction causes the up / down counter circuit 8 to be -1.
Then, the operation state signal 71 stored in the operation state register circuit selected by the up / down counter circuit is returned to the controlled circuit 7, and the instruction set in the instruction register circuit selected by the up / down counter circuit is set. Is sent to the controlled circuit 7.

By providing these instructions, the MPU writes a new operation instruction without reading the operation state of the controlled circuit 7 or the instruction currently set, and executes an operation different from the current operation state. After that, it is possible to return to the previous operation state without writing a new operation command or an operation state.

By providing the operation state register circuit 11 to the operation state register circuit 16 in this manner, an operation for faithfully returning the operation state inside the controlled circuit 7 can be performed.

[0062]

According to the integrated circuit of the present invention, in order to share a peripheral circuit in a system that performs a time-divisional operation in which software is switched at regular intervals or a system that performs interrupt processing, the current operating state and internal state are peripherally shared. There is no need to read the data from the inside of the circuit and save the work. By receiving the switching instruction from the MPU and selecting the instruction register according to it, it is possible to easily switch between multiple operating states. There is an effect that software switching or interrupt processing can be performed without reducing the processing capacity.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment circuit example of the present invention.

FIG. 2 is a block diagram of a second embodiment circuit example of the present invention.

FIG. 3 is a block diagram of a third embodiment circuit example of the present invention.

[Explanation of symbols]

 1 control circuit 2 switching instruction register circuit 3 write selection control circuit 4 instruction register circuit 5 instruction register circuit 6 selector circuit 7 controlled circuit 8 up-down counter circuit 9 instruction register circuit 10 integrated circuit 11 operating state register circuit 12 operating state register circuit 16 operation state register circuit 101 write control signal 102 write data signal 21 switching instruction signal 31 write signal 32 write signal 33 selection signal 39 write signal 41 instruction output signal 51 instruction output signal 61 instruction output signal 71 operating state signal 81 counter output 91 instruction Output signal

Claims (3)

[Claims] 1. An integrated circuit formed by a controlled circuit, the internal operating state of which changes in response to a command, and a control circuit, which receives a control command from the outside and outputs it to the controlled circuit, A control circuit holds a plurality of instruction register circuits for holding operation instructions from the outside, a selector circuit for sending the output of the instruction register circuits to the controlled circuit, and a write selection for the plurality of instruction register circuits and the selector. An integrated circuit comprising a write selection control circuit for controlling output selection of the circuit, and a switching instruction register circuit for outputting to the write selection control circuit in response to an external switching instruction. 2. The integrated circuit according to claim 1, wherein the control circuit includes an up-down counter circuit connected to an instruction register circuit and outputting to a write selection control circuit. 3. The integrated circuit according to claim 2, wherein the control circuit comprises a plurality of operation state register circuits which are controlled by the output of the write selection control circuit and which are connected to the controlled circuit and hold the operation state signals thereof.