JP2000022076A - Macro module control device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a macro module in useless power consumption by a method wherein the macro module which is not required to be used is stopped from operating when a MCU is in a standby mode without increasing a circuit in scale and a wiring in area. SOLUTION: When an MCU is in a standby mode, a power control dedicated pin 4 is kept at a high level, an outer pin 5 and a clock control resistor 7 are connected together through the intermediary of a multiplexer 6, control pulse signals of high level are inputted into a control register 7 through an outer pin 5 to set the clock control register 7. By this setup, signals of high level are outputted to a logic circuit 8 from the clock control register 7 to shut off the logic circuit 8, and clock signals are stopped from being supplied to a functional macro module, whereby useless power consumption can be reduced. At this point, a decoder circuit can be dispensed with, so that a circuit is restrained from increasing in scale, and as an existing wiring is used, a wiring is prevented from increasing in area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for controlling a macro module in a standby mode of a plurality of function macro modules incorporated in a one-chip microcomputer or the like.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram for explaining a conventional method for controlling a function macro module such as a timer and a serial interface in an MCU (microcomputer). Function macro modules 2A, 2B in MCU 1
Even in the standby mode in which only 2C operates, the clock is supplied to the entire macro module because the select signal 200 for selecting the macro module decoded and generated by the address decoder 3 from the input address 100 is common. The macro modules that did not need to be used also operated, consuming extra power in this area.

[0003]

As a countermeasure for reducing the power consumed by a macro module which does not need to be used in the standby mode as described above, a functional macro module is provided by an address decoder 3 as shown in FIG. Select signals 201, 202, 203 for selecting
Are generated individually to stop the operation of the macro module that does not need to be used in the standby mode, or to cause a control register in the functional macro module to perform a process of controlling its power. However, each of these methods requires address decoding for each functional macro module, and thus has a problem that the circuit scale of the address decoder 3 is increased. There is also a problem that the routing of the select signals 201 and 202 for each functional macro module increases the wiring area in the chip.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a macro module which does not need to be used in a standby mode of an MCU without increasing the circuit scale and wiring area. It is an object of the present invention to provide a macro module control device and method capable of stopping the operation of the macro module and reducing unnecessary power consumption.

[0005]

In order to achieve the above object, a first aspect of the present invention is a macro module control device for controlling the operation of a macro module built in a microcomputer. An external pin, a control circuit for controlling whether to supply a clock to the macro module or stop the clock according to an input control signal, and connecting the external pin to the macro module or to the control circuit. And a dedicated pin for inputting a power save signal for switching the switching circuit to the control circuit side, and inputting the power save signal from the dedicated pin when the microcomputer is in a standby mode. After that, the control circuit supplies a clock to the macro module. It is to input a control signal for stopping from the external pins.

According to the first aspect, when the macro module does not need to operate in the standby mode of the microcomputer, the power save signal is input from the dedicated pin in the standby mode, and After the pin is connected to the control circuit via the switching circuit, a control signal for stopping the clock is input from the external pin to the control circuit, and the supply of the clock to the macro module is stopped. This allows
The operation of the macro module is stopped, and power consumption is reduced.

According to a second aspect of the present invention, in a macro module control device for controlling the operation of a macro module built in a microcomputer, an external pin for inputting / outputting a signal and a control signal input to the macro module. A control circuit that controls whether to supply a clock or stop the clock, a switching circuit that selects and switches whether to connect the external pin to the macro module or to the control circuit, and the microcomputer. A signal generation circuit for generating a switching signal for switching the switching circuit from the standby mode signal to the control circuit side, and a setting circuit for setting a predetermined potential to the external pin. In the mode, the potential state of the external pin is controlled by the control. It is to be inputted to the control circuit via the switching circuit as No..

According to the second aspect, when the macro module does not need to operate during the standby mode of the microcomputer, the setting circuit sets a high-level potential to the external pin, and Pull up. Thereafter, when entering the standby mode, the external pin is switched to the control circuit side via the switching circuit by a switching signal generated by the signal generating circuit, and a pull-up signal of the external pin is used as the control signal. Input to the control circuit. In response to this, the control circuit stops supplying the clock of the macro module.

As a result, the operation of the macro module is stopped, and power consumption is reduced. If a ground potential is applied to the external pin and the pull-down voltage is applied, the pull-down voltage is input from the external pin to the control circuit as the control signal in the standby mode. Continue to supply clock to.

A third feature of the invention resides in that the setting circuit has a resistor for applying a pull-up voltage or a pull-down voltage to the external pin.

A fourth aspect of the present invention is characterized in that the control circuit controls the clock by the macro by a register set or reset by the potential of the input control signal and an output signal when the register is set or reset. And a logic circuit for controlling whether to supply or stop supplying the module.

According to a fifth aspect of the present invention, there is provided a method of controlling a macro module for controlling the operation of a macro module incorporated in a microcomputer, the method comprising: receiving a signal from the outside when the microcomputer is in a standby mode; Providing a path for inputting the clock to the hardware for supplying and stopping the clock, and selectively stopping the supply of the clock to the macro module by inputting the control signal from the outside to the hardware. And that it had.

According to the fifth aspect, when the macro module does not need to operate in the standby mode of the microcomputer, a control signal is input to the hardware by applying a signal from the outside in the standby mode. After securing the path, the supply of the clock to the macro module is stopped by further sending the control signal from the outside to the hardware.

According to a sixth aspect of the present invention, there is provided a method of controlling a macro module which controls the operation of a macro module incorporated in a microcomputer, wherein a switching signal is generated from an internal signal for setting the microcomputer to a standby mode. Supplying a clock with a setting signal set in advance by the switching signal, securing a path for inputting the clock to hardware for stopping the supply, and supplying the setting signal from the hardware to the macro module to supply a clock to the macro module. It consists in selectively stopping the supply or selectively continuing the supply of the clock.

According to the sixth aspect, when the macro module does not need to operate when the microcomputer is in the standby mode, a setting for stopping clock supply to the macro module is made in advance. When the standby mode is entered, the switching signal is automatically created, and the setting signal is input to the hardware circuit.
The hardware circuit stops supplying a clock to the macro module. When the macro module needs to operate, the setting for supplying the clock to the macro module in the standby mode may be performed in advance.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of an MCU equipped with a control device for a macro module according to the present invention. However, portions corresponding to the conventional example will be described using the same reference numerals. The MCU (microcomputer) 1 incorporates a plurality of function macro modules (not shown) in addition to the function macro module 2A.
The MCU 1 is provided with a power control dedicated pin 4 for controlling power consumption of the function macro module 2A. The power control dedicated pin 4 is connected to a multiplexer 6 provided inside the MCU 1, and the multiplexer 6 is connected to an external pin 5 for the function macro module 2A.

The multiplexer 6 connects the external pin 5 to the clock control register 7 or the function macro module 2
Select whether to connect to the input section of A. The clock control register 7 is a logic circuit 8 for conducting and blocking the clock 300.
And the clock 300 is supplied to the function macro module 2A via the logic circuit 8.

The function macro module 2A is the MCU 1
Operation is unnecessary in the standby mode.
In addition, a multiplexer 6, a clock control register 7, a logic circuit 8
And a similar circuit is configured, but the power control dedicated pin 4 is common and one.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG. In normal mode,
Since the multiplexer 6 selects the function macro module 2A, the external pin 5 is connected to the function macro module 2A.
Is connected to At this time, since the clock control register 7 has been reset, the output 50 of FIG.
The logic circuit 8 is conducting at a low level as shown in FIG. Thus, the clock 300 is supplied to the function macro module 2A as shown in FIG. 2D, and the function macro module 2A operates. Therefore, the function macro module 2A performs an operation of processing a signal from the external pin 5, for example.

In the standby mode of the MCU 1 (mode in which only the function macro module operates), the power control dedicated pin 4 is enabled to a high level as shown in FIG. Thus, the multiplexer 6 selects the clock control register 7 side, so that the external pin 5 is connected to the clock control register 7 via the multiplexer 6.

Thereafter, when a high-level pulse signal is input from the external pin 5 to the clock control register 7 as shown in FIG. 2B, the clock control register 7 is set. When the clock control register 7 is set,
As shown in FIG. 2C, a high-level signal 50 is output to the logic circuit 8, and the logic circuit 8 is turned off.

Therefore, as shown in FIG. 2D, the clock 300 input to the function macro module 2A through the logic circuit 8 is cut off, the supply of the clock 300 to the function macro module 2A is stopped, and the function By stopping the operation of the macro module 2A, the power consumption of the functional macro module 2A is eliminated.

Thereafter, when the standby mode is released, the reset signal 40 is input to the clock control register 7.
By inputting 0, the clock control register 7 is reset. As a result, a low-level signal 50 is output from the clock control register 7 to the logic circuit 8 to make the logic circuit 8 conductive. As a result, the clock 300 is supplied to the function macro module 2A to operate the function macro module 2A.

According to the present embodiment, when the MCU 1 is in the standby mode, the power control dedicated pin 4 is enabled and then a high-level control pulse signal is input to the external pin 5 of the macro module 2A that does not need to operate. The supply of the clock to the macro module 2A which does not need to be operated can be stopped, whereby the operation of the macro module 2A can be stopped and unnecessary power consumption can be reduced.

In addition, a circuit for decoding addresses such as the function macro module 2A becomes unnecessary, and one dedicated power control pin 4, a multiplexer 6 provided for each macro module, a clock control register 7,
Since the circuit scale of the logic circuit 8 is small, the MCU 1 is
Circuit size is not increased.

Further, since the existing wiring path from the external pin to the logic circuit for realizing this function is used, the conventional wiring such as the routing of the select signal is not required, and the wiring area is not increased.

As a result, the clock of the function macro module can be selectively stopped with a small amount of hardware, and low power consumption of the MCU 1 can be realized.

FIG. 3 is a block diagram showing a second embodiment of an MCU equipped with a control device for a macro module according to the present invention. However, portions corresponding to the conventional example will be described using the same reference numerals. The MCU (microcomputer) 1 includes a plurality of other function macro modules (not shown) such as function macro modules 2A and 2B.

The external pin 5A is connected to the function macro module 2 via a multiplexer 6A provided inside the MCU 1.
A or the clock control register 7A, and the external pin 5B is connected to the functional macro module 2B or the clock control register 7B via the multiplexer 6B. The clock control register 7A is a logic circuit 8 that conducts and shuts off the clock to the function macro module 2A.
A, and the clock control register 7B controls the logic circuit 8B that conducts and cuts off the clock to and from the functional macro module 2B.

A standby mode signal 500 for setting the MCU 1 in a standby mode is supplied to the multiplexer control signal 600 via the logic circuit 9 and becomes a multiplexer 6.
A, 6B. The logic circuit 9 includes a delay element 10
To generate a multiplexer control signal 600 which is a one-shot pulse from the standby mode signal 500. Further, the external pin 5A is pulled up by applying a voltage Vcc through a high-resistance resistor R,
The external pin 5B is pulled down by being grounded via a high-resistance resistor R.

The function macro module 2A is the MCU 1
Operation is unnecessary in standby mode. A multiplexer 6, a clock control register 7, and a logic circuit 8 are provided for each of the other function macro modules (not shown) to constitute a similar circuit. However, a multiplexer control signal 600 from the logic circuit 9 is shared by all the multiplexers. Is entered.

Next, the operation of this embodiment will be described. During normal operation, the standby mode signal 500 is
As shown in (A), when the output 6 of the logic circuit 9 is at the low level,
00 is at a low level as shown in FIG.
The multiplexers 6A and 6B are connected to the function macro module 2
A and 2B sides are selected. Thereby, the external pins 5
A and external pins 5B are multiplexers 6A and 6B, respectively.
Are connected to the function modules 2A and 2B via the.
In this case, the clock control registers 7A and 7B are reset and the output 50 thereof is at the low level as shown in FIG. 4C, so that the logic circuits 8A and 8B are in the conductive state, and FIG. As shown in (1), the clock 300 is supplied to the function macro modules 2A and 2B, and the function macro modules 2A and 2B are operating.

In this state, when a signal is input to the external pin 5A or the external pin 5B, the signal is input to the function macro modules 2A and 2B and processed by each function macro module. At this time, since the external pins 5A and 5B are pulled up or pulled down by the high-resistance resistor R, the input signals are not affected.

Thereafter, when the standby mode signal 500 goes high as shown in FIG. 4A and the MCU 1 enters the standby mode, the logic circuit 9 outputs the high level multiplexer control signal as shown in FIG. 4B. Signal 60
0 is output to the multiplexers 6A and 6B. The multiplexers 6A and 6B are connected to the multiplexer control signal 600.
Are high level, the clock control registers 7A, 7B
To select the side, the external pins 5A, 5B are connected to the clock control registers 7A, 7B via multiplexers 6A, 6B.
Connected to.

At this time, since the external pin 5A is pulled up via the resistor R, a high-level control signal is input to the clock control register 7A, and the clock control register 7A is set. The set clock control register 7A outputs a high-level output signal 50 to the logic circuit 8A as shown in FIG.
Is shut off, and the clock 300 supplied to the function macro module 2A is stopped as shown in FIG. 4D, and the function macro module 2A stops operating.

On the other hand, since the external pin 5B is pulled down via the resistor R, a low-level signal is input to the clock control register 7B, so that the clock control register 7B remains reset. Therefore, the output 50 of the clock control register 7B remains at the low level, the logic circuit 8B maintains the conductive state, the clock 300 continues to be supplied to the functional macro module 2B, and the functional macro module 2B enters the standby mode. Even working.

According to the present embodiment, when the MCU 1 is in the standby mode, the clock 300 supplied to the function macro module 2A which does not need to operate is automatically stopped, and the operation of the function macro module 2A is stopped.
Unnecessary power consumption can be reduced, and there is an effect similar to that of the first embodiment shown in FIG. Moreover, in this embodiment, since the above-described power save control is performed using the internal standby mode signal 500, the power control dedicated pin required in the first embodiment shown in FIG. 1 can be omitted, and It is not necessary to apply a power control signal to the external pin 5A, and the operability is improved.

[0038]

As described in detail above, according to the present invention, the operation of the macro module which is not required to be used in the standby mode is stopped without increasing the circuit scale and the wiring area, and the wasteful power is consumed. Consumption can be reduced,
Low power consumption of the MCU can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an MCU equipped with a macro module control device of the present invention.

FIG. 2 is a timing chart illustrating a power save control operation in FIG.

FIG. 3 is a block diagram showing a second embodiment of an MCU equipped with a control device for a macro module according to the present invention.

FIG. 4 is a timing chart illustrating a power save control operation in FIG. 3;

FIG. 5 is a block diagram showing a configuration example of a conventional MCU.

FIG. 6 is a block diagram illustrating a control method of a function macro module in a conventional MCU.

[Explanation of symbols]

 Reference Signs List 1 MCU 2A, 2B function macro module 4 Power control dedicated pin 5 External pin 6, 6A, 6B multiplexer 7, 7A, 7B Clock control register 8, 8A, 8B, 9 Logic circuit 10 Delay element

Claims (6)

[Claims] 1. A control device of a macro module for controlling the operation of a macro module built in a microcomputer, comprising: an external pin for inputting / outputting a signal; and supplying a clock to the macro module by an input control signal. A control circuit for controlling whether to stop a clock, a switching circuit for selecting whether to connect the external pin to the macro module or to connect to the control circuit, and switching the switching circuit to the control circuit side A dedicated pin for inputting a power save signal to be switched, and a control signal for stopping supply of a clock to the macro module by the control circuit after the power save signal is input from the dedicated pin in a standby mode of the microcomputer. Is input from the external pin. The control device of the macro module that. 2. A control device for a macro module for controlling operation of a macro module built in a microcomputer, comprising: an external pin for inputting / outputting a signal; and supplying a clock to the macro module according to an input control signal. A control circuit for controlling whether to stop the clock, a switching circuit for selecting and connecting whether to connect the external pin to the macro module or to the control circuit, and a standby for setting the microcomputer to a standby mode A signal generation circuit for generating a switching signal for switching the switching circuit from the mode signal to the control circuit side; and a setting circuit for setting a predetermined potential to the external pin. The potential state of the external pin is used as the control signal to switch off. A control device for a macro module, which is inputted to the control circuit via a switching circuit. 3. The macro module control device according to claim 2, wherein the setting circuit has a resistor for applying a pull-up voltage or a pull-down voltage to the external pin. 4. The control circuit supplies a clock to the macro module according to an output signal when the register is set or reset by a register set or reset by the potential of the input control signal, 3. The control device for a macro module according to claim 1, further comprising a logic circuit for controlling whether to stop the supply. 5. A control method of a macro module for controlling an operation of a macro module built in a microcomputer, comprising: supplying a signal from outside and supplying a control signal from outside during a standby mode of the microcomputer; A step of securing a path to be input to hardware for stopping, and a step of selectively stopping supply of a clock to the macro module by inputting the control signal from the outside to the hardware. Characteristic macro module control method. 6. A control method of a macro module for controlling operation of a macro module built in a microcomputer, comprising: a step of generating a switching signal from an internal signal for setting the microcomputer to a standby mode; A step of securing a path for inputting the set setting signal to hardware for supplying and stopping the clock, and selectively stopping supply of the clock to the macro module by inputting the setting signal by the hardware. Or a step of selectively continuing the supply of the clock.