JPH06119257A - Large scale integrated circuit incorporating internal state saving structure - Google Patents

Abstract

PURPOSE:To dispense with an external memory and an external memory power source, and to decrease a delay time at the time of start and stop of the whole system by incorporating an internal state saving structure for resetting an internal state from a storage means when reset of the internal state is instructed. CONSTITUTION:The large scale integrated circuit(LSI) 10 is provided with a flash memory 12 being a storage means for saving an internal state 11 of the LSI 10, a data copying circuit 13 being a data moving means for reading and writing the internal state 11 to the flash memory 12, and a circuit 14 which does not contain the internal state. In such a state, when the system for restarting an operation from a state at the time when a power source is turned on when the power source is turned on by using the LSI 10 is constructed, since the LSI 10 incorporates a saving structure of the internal state 11, an external memory and an external memory power source except the power source of the LSI 10 main body become unnecessary. Also, when the power source is disconnected, and the power source is turned on, the internal state of the LSI 10 is not transferred to the outside of a chip, therefore, a delay time at the time of rise and fall of the whole system becomes small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large scale integrated circuit containing an internal state saving structure.

[0002]

2. Description of the Related Art In a conventional large-scale integrated circuit (hereinafter referred to as an LSI), the internal state stored in a register, a random access memory (RAM) or the like is lost when the power is turned off. Therefore, in order to construct a system that uses LSI to restart the operation from the state when the power is turned off when the power is turned on, the internal state 41 of the LSI 40 is read outside the chip when the power is turned off and stored in the external memory 42, and when the power is turned on. It was necessary to take out the internal state 41 of the LSI 40 from the external memory 42 and write it again in the chip. Therefore, in order to construct a system that resumes the operation from the state when the power is turned off when the power is turned on by using the conventional LSI, as shown in FIG. 7, the internal state 41 of the LSI 40 is stored in addition to the power source 43 of the LSI 40. External memory 42 and external memory 42
Need to provide an external memory power supply 44 for holding data.

[0003]

DISCLOSURE OF THE INVENTION The conventional LSI described above
In a system that restarts the operation from the state when the power is turned off when the power is turned on, it is necessary to provide an external memory for storing the internal state of the LSI and an external memory power source for the external memory to hold data. There is a problem that the system configuration becomes complicated. In addition, there is a problem in that it takes a long time to transfer the internal state of the LSI to the outside of the chip when the power is turned off and turned on, and the delay time at the time of starting and shutting down the entire system increases.

In view of the above-mentioned problems in the system using the conventional LSI, the present invention has a simple system configuration and can reduce the operation time of the LSI at the time of turning off the power and turning on the power, thereby starting up the entire system. Shut down
To provide an LSI that can be performed.

[0005]

The present invention comprises storage means for saving the internal state and data moving means for reading / writing the internal state from / to the storage means. This is achieved by a large-scale integrated circuit having an internal state saving structure that saves the internal state in the storage unit when the saving is instructed and restores the internal state from the storage unit when the internal state is instructed.

[0006]

In the large scale integrated circuit of the present invention, the storage means saves the internal state, the data moving means reads / writes the internal state from / to the storage means, and when the data moving means instructs the saving of the internal state, the internal state is saved. The state is saved in the storage means, and the internal state is restored from the storage means when the restoration of the internal state is instructed.

[0007]

Embodiments of the large-scale integrated circuit (hereinafter referred to as LSI) of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the LSI of the present invention.

The LSI 10 shown in FIG. 1 is an internal state 11 of the LSI 10.
Flash memory 12, which is a storage means for saving
A data copy circuit 13, which is a data moving means for reading / writing the internal state 11 from / into the flash memory 12, and a circuit 14 not including the internal state are provided.

Next, the operation of the LSI 10 shown in FIG. 1 will be described with reference to FIG.

In the LSI 10 of FIG. 1, the data copy circuit 13
Saves the internal state 11 to the flash memory 12 when the internal state save is instructed (see FIG. 2A), and restores the internal state 11 from the flash memory 12 when the internal state restore is instructed (see FIG. 2). (See (b)).

FIG. 3 shows a calculator 1 to which the LSI of FIG. 1 is applied.
It is a block diagram showing an example of 1 composition of a chip microcomputer (henceforth a microcomputer).

The microcomputer of FIG. 3 includes a register group 15, an arithmetic unit (ALU) 16, a data random access memory (RAM) 17, a frame memory 18, data copy circuits 19 to 22 for each partial circuit, and each part. Flash memories 23 to 26 for storing the internal state of the circuit, instruction decoder 27, reader
Dedicated memory (ROM) 28, key input control circuit
29 and a liquid crystal driver 30.

The register group 15 includes a program counter, a control register, an arithmetic register, and a general-purpose register (not shown).

Of the partial circuits constituting the microcomputer, the register group 15, the ALU 16, the data RAM 17, and the frame memory 18 are, as shown in the figure, a data copy circuit 19 for storing the internal state of each partial circuit. 22 and flash memories 23 to 26 are provided.

The saving operation of the internal state of the microcomputer shown in FIG. 3 will be described with reference to FIG.

First, an instruction for saving and restoring the internal state is prepared in the instruction set of the microcomputer.

When these instructions are decoded by the instruction decoder 27, they change the control signal 31 shown in FIG.

The data copy circuits 19 to 22 receive the control signal 31 and operate based on the operation principle of FIG. That is,
When the control signal 31 saves the internal state, the internal states of each partial circuit are saved in the flash memories 23 to 26 for each partial circuit, and when the control signal 31 returns the internal state, the internal state of each partial circuit is changed to each partial circuit. Restore from flash memory 23-26 for.

Next, referring to the flow chart of FIG.
The operation timing of saving and restoring the internal state in the microcomputer of FIG. 3 will be described.

First, the display routine is executed (step S
1) It is determined whether or not a specific key of the calculator is pressed (step S2). When it is determined that the specific key is pressed (YES) in step S2, the internal state is saved and restored. (Step S3), the process proceeds to step S4 described later. On the other hand, when it is determined in step S2 that the specific key is not pressed (NO), a calculation routine is executed (step S4), and it is determined whether the specific key of the calculator is pressed (step S4). S5) If it is determined in step S5 that the specific key is pressed (YES), the internal state is saved and restored (step S6), and the process proceeds to step S7 described later. On the other hand, when it is determined in step S5 that the specific key is not pressed (NO), it is determined whether or not the calculation routine is finished (step S7), and the calculation routine is determined in step S7. When it is determined that the calculation routine is completed (YES), the process returns to step S1. When it is determined that the calculation routine is not completed (NO) in step S7, the process returns to step S4.

To summarize the above steps, the internal state is saved during the termination process before the power is turned off, and the internal state is saved during the initialization after the power is turned on. Then, when a specific key of the calculator is pressed, the internal state is saved and restored.

As shown in FIG. 6, if a system is constructed using the LSI 10 of the present invention to restart the operation from the state when the power is turned off when the power is turned on, the LSI 10 of the present invention will have an internal state 11
Since the evacuation structure is built in, an external memory and an external memory power supply other than the power supply 32 of the LSI 10 main body are unnecessary. In addition, since the internal state of the LSI 10 is not transferred to the outside of the chip when the power is turned off or turned on, the delay time at the time of starting and shutting down the entire system is reduced.

These characteristics are particularly effective when the LSI of the present invention is used as a constituent element of a portable device for finely controlling power supply and saving power consumption.

[0025]

The large-scale integrated circuit of the present invention is provided with the storage means for saving the internal state and the data moving means for reading / writing the internal state from / to the storage means. The internal state saving structure that saves the internal state to the storage means when the saving of the internal state is instructed and restores the internal state from the storage means when the internal state is instructed is built-in. No power supply for memory is needed. In addition, since the internal state of the LSI is not transferred to the outside of the chip when the power is turned off or turned on, the delay time at the time of starting and shutting down the entire system is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a large scale integrated circuit of the present invention.

FIG. 2 is an operation explanatory diagram of the data copy circuit of FIG.

3 is a block diagram showing a configuration example of a one-chip microcomputer for a calculator to which the large scale integrated circuit of FIG. 1 is applied.

FIG. 4 is an explanatory diagram of a control method of the data copy circuit of FIG.

5 is a flowchart for explaining the operation of the calculator 1-chip microcomputer in FIG. 3. FIG.

6 is a block diagram showing a configuration example of a system using the LSI of FIG.

FIG. 7 is a block diagram showing a configuration example of a system using a conventional LSI.

[Explanation of symbols]

 10 Large scale integrated circuit (LSI) 11 Internal state 12 Flash memory 13 Data copy circuit 14 Circuit not including internal state

Claims (1)

[Claims] 1. A storage unit for saving an internal state,
A data moving unit for reading / writing the internal state from / to the storage unit, and saving the internal state to the storage unit when the data moving unit gives an instruction to save the internal state, A large-scale integrated circuit having an internal state saving structure, wherein the internal state is restored from the storage means when an instruction to restore the state is given.