JPH07141063A - Computer system - Google Patents

Abstract

PURPOSE:To solve a problem of heat radiation from a microprocessor without mounting a large cooling plate and air-cooling fan. CONSTITUTION:This system is a computer system equipped with the microprocessor 101 and a circuit 103 which generates a clock signal to drive the microprocessor 101. It is also provided with a circuit 102 which measures the temperature on the chip surface of the microprocessor 101 and a circuit 104 which controls the frequency of a clock signal phiclk2 to be supplied to the microprocessor 101. The computer system is the one with structure capable of varying the frequency of the clock signal phiclk2 to be supplied to the microprocessor 101 by the temperature on the chip surface of the microprocessor 101, and of preventing the temperature of the microprocessor 101 from exceeding a regulated value.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to computer systems.

[0002]

2. Description of the Related Art In recent years, the performance of microprocessors in computer systems has been remarkably improved. This improvement in performance is achieved by both improving the performance of the microprocessor itself by adopting new architectures such as pipeline processing and superscalar processing, and by increasing the frequency of the clock signal that drives the microprocessor. It is a thing.

As the frequency of the driving clock signal of the microprocessor becomes higher, the microprocessor emits more heat from the chip body, and this heat generation becomes a problem in the design of computer system. That is, when a computer system equipped with such a microprocessor is continuously used for a long period of time, the temperature of the microprocessor itself and the inside of the system housing rises due to the accumulation of the amount of heat generated by the microprocessor, which may cause the system to malfunction. This is because there is a risk of causing damage to the element.

In order to deal with this heat generation problem, in recent computer systems, a large heat dissipation plate or an air cooling fan is attached to a microprocessor chip, or a large air cooling fan is attached to a system body. Heat radiation measures such as taking sufficient flow rate are taken.

On the other hand, in recent years, the so-called notebook type and sub-notebook type portable computers have been remarkably popularized. These renewed the image of a conventional desktop computer that occupies most of the desk space, and succeeded in putting the computer system in the case of A4 or B5 size and tens of millimeters in thickness. There is. And this type of computer can be used even where there is no power socket,
It is designed so that it can be driven by a battery power source such as a dry cell.

By the time these portable computers began to appear in the world, in terms of performance, portable computers were
The general idea was that even if it was inferior to a stationary computer, it could not be helped. However, recently, there is an increasing demand for portable computers to have the same computing performance as that of stationary computers.

[0007]

When a high-performance, high-frequency driven microprocessor is mounted on a portable computer in order to meet the above requirements, heat dissipation from the microprocessor becomes a serious problem. In a portable computer, firstly there is a problem of space to realize a small size and thin shape, and secondly, there is a problem of power consumption to secure a driving time by a battery. Therefore, a large heat sink like a stationary computer is used. This is because it is difficult to take heat measures to install a fan for air cooling.

For this reason, in the conventional portable computer system, a microprocessor having a low driving frequency and a small amount of heat generation has to be adopted, and it is not possible to meet the demand for high performance.

An object of the present invention is to solve the problem of heat radiation from the microprocessor and to enable the use of a high-performance microprocessor with a high driving frequency without attaching a large radiator plate or an air cooling fan. .

[0010]

To solve the above problems, a computer system of the present invention comprises means for measuring the temperature of the surface of a microprocessor chip and means for changing the frequency of a clock signal supplied to the microprocessor. During the system operation, the frequency of the clock signal supplied to the microprocessor is changed according to the temperature of the surface of the microprocessor chip to prevent the temperature of the microprocessor chip from exceeding a specified value.

[0011]

Embodiment 1 The basic configuration of the present invention is shown in FIG. In FIG. 1, 101 is a microprocessor, 102 is a temperature measurement circuit, 103 is a clock signal generation circuit, 104 is a frequency control circuit, and φclk1 is a clock signal generation circuit 1
Φclk2 is the original clock signal generated in 03, and φclk2 is the clock signal supplied to the microprocessor 101.
freq indicates a frequency control signal, respectively.

Most microprocessors in recent years are CMOs.
If the frequency of the drive clock signal is less than or equal to the upper limit, the operation can be performed at any value. Although the arithmetic performance of the microprocessor increases in proportion to the driving clock frequency, the amount of heat generated from the microprocessor chip also increases as the frequency increases.

In a conventional computer system,
Since the frequency of the clock signal that drives the microprocessor was constant, in order to reduce the heat generated from the microprocessor chip, the microprocessor was always driven by the clock signal with a low frequency, so the computing performance also decreased at the same time. Was there.

In the computer system of the present invention, the microprocessor 101 is normally driven by a clock signal having a high frequency. Temperature measuring circuit 10
2 constantly measures the surface temperature of the microprocessor chip, and when the temperature reaches a predetermined value, a control signal φf for frequency reduction is sent to the frequency control circuit 104.
The frequency control circuit 104 which issues the req and receives this control signal controls the microprocessor 101 by suppressing the heat generation by reducing the frequency of the clock signal φclk2 supplied to the microprocessor 101.

It is necessary to experimentally obtain the temperature value at which the frequency is switched and the frequency value at the time of frequency reduction, which are defined in advance, based on the maximum rating of the microprocessor from the rate of change in the amount of heat generated by the frequency and the operating conditions. .

To measure the temperature on the surface of the microprocessor chip, a temperature measuring element 202 is mounted on the surface of the chip 201 as shown in FIG. In order to measure the surface temperature as accurately as possible, it is necessary to keep the contact thermal resistance low by, for example, bringing the temperature measuring element 202 into close contact with the surface of the chip 201 at the time of mounting and filling the area with putty.

As the temperature measuring element, a temperature measuring resistor such as a thermistor or a platinum temperature measuring resistor, or a thermocouple or a pn junction semiconductor having a voltage change with temperature can be used.

Temperature measuring circuit 102 using a resistance temperature detector
FIG. 3 shows a configuration example of the frequency control circuit 104. In FIG. 3, 301 is a microprocessor, 302 is a resistance temperature detector, 303 is a resistance switching circuit, 304 is a comparison operation circuit, 305 is a clock signal generation circuit,
6 is a frequency dividing circuit, 307 is a synchronizing circuit, and 308 is a clock signal selecting circuit. There are some resistance temperature detectors whose resistance value increases as the temperature rises and those whose resistance value decreases conversely, but the circuit of FIG. 3 will be described here assuming that the former is used.

By continuously using the microprocessor 301 driven by the high frequency clock signal, the microprocessor chip 30 can be used over time.
1 The temperature of the surface rises, and as a result, the resistance temperature detector 302
Since the resistance value of No. 2 increases, the value of voltage Vthm increases.

The value of the voltage Vthm is a reference value Vref determined by the values of the resistor R2 and the resistor switching circuit 302.
When it reaches, the comparison arithmetic circuit 303 issues a control signal φfreq for frequency reduction.

In the circuit of FIG. 3, as the frequency conversion means, the original clock signal φclk1 and the selective output of the clock signal φ1 divided by the frequency dividing circuit 306 from the original clock signal φclk1 are used. Two clock signals, the original clock signal φclk1 and the divided clock signal φ1, are constantly input to the clock signal selection circuit 308, and the selection circuit 308 receives the control signal φ from the synchronization circuit 307.
According to 2, either clock signal is output.

The synchronizing circuit 307 is provided to synchronize the control signal φfrq with the divided clock signal φ1. This is to prevent the signal width of the clock signal φclk2 from becoming inconsistent due to the frequency switching being performed in an arbitrary phase. Clock signal φ1
By controlling with the control signal φ2 synchronized with the clock signal, switching of the clock signal is always performed with the clock signal width guaranteed at a constant phase.

The clock signal selection circuit 308, which has received the frequency reduction control signal φ2, switches the clock signal φ2 supplied to the microprocessor to the low frequency clock signal φ1 obtained by dividing the original clock signal φclk1.
The heat generation amount of the microprocessor 301 whose driving frequency is lowered is reduced, and the surface temperature is gradually lowered.

The resistance switching circuit 303 is provided to change the reference voltage Vref when the frequency of the clock signal φclk2 is reduced. The reference voltage Vref is always the same value, and it is possible to perform control only with the reference value, but in order to stabilize the control and increase the cooling effect, the reference voltage Vref should be changed during frequency reduction. Is an effective means.

The surface temperature of the microprocessor 301 is lowered, and the value of the voltage Vthm is reduced to the reference voltage Vre.
When the voltage drops to the value of f, the selection circuit 308 again starts supplying the high-frequency original clock signal φclk1 to the microprocessor.

As described above, the computer system of the present invention can prevent the temperature of the microprocessor from exceeding the rated value and abnormally rising, even without a large radiator plate or air cooling fan. Then, when the temperature of the microprocessor rises especially, the frequency of the drive clock signal is reduced and the computing performance is temporarily reduced, but the microprocessor is driven by the high frequency clock signal for most of the other time. High-speed arithmetic processing is possible.

An example of an actual circuit diagram having the structure described in FIG. 3 is shown in FIG. 4, reference numeral 403 denotes an analog switch, which plays a role of the resistance switching circuit 303 in FIG. When the control signal φfrq is at the HI level, Vref = Vcc * R3 / (R2 + R3),
When the control signal φfrq becomes LOW level, Vref = V
cc * R3 / (R2 + R3 + R2 * R3 / R4).

Reference numeral 404 is a comparison operator, Vthm> V
The HI level is output at ref, and the LOW level is output at Vthm <vref. Reference numeral 405 is a crystal oscillator, and an original clock signal φc is generated by an oscillation circuit using an inverting amplifier circuit 406.
lk1 is generated.

Reference numerals 407 and 408 denote rising edge operation data type flip-flops. The flip-flop 407 corresponds to the frequency dividing circuit 306 and the flip-flop 408 corresponds to the synchronizing circuit 307 in FIG. In the circuit of FIG. 4, the division ratio is set to 1/2 for simplification.

The temperature measuring circuit using the resistance temperature detector is a linearizing circuit for correcting the non-linearity of the temperature-resistance relation in the resistance temperature detector in an application requiring a particularly precise temperature measurement such as a thermometer. In some cases, a circuit for compensating the resistance of the lead wire between the resistance temperature detector and the comparison calculation circuit may be added. However, in the application of the present invention, these correction circuits are omitted in FIG.
It is thought that a simple circuit such as that shown in can sufficiently fulfill its function.

In the circuit of FIG. 4, control is performed with two reference values, but if more detailed control is desired, control with an increased number of reference values is effective. FIG. 5 shows a configuration example of a system in which the reference value value is increased. In FIG. 5, 503 is a 3-bit analog-digital conversion circuit, 505 is a multi-stage frequency dividing circuit, φfreq1 to φfreq3 are frequency control signals, and φ1 to φ7 are frequency-divided clock signals.

In the system shown in FIG. 5, the voltage Vthm according to the temperature of the surface of the microprocessor 501 sent from the temperature measuring circuit 502 is digitized by the analog-digital conversion circuit 503, and the clock signal selection is received. The circuit 506 is controlled to select and output a clock signal according to the control signal.

Further, FIG. 6 shows an example of the configuration of a system having a structure in which the frequency is continuously changed according to the temperature of the surface of the microprocessor. In FIG. 6, 602 is a resistance temperature detector having a positive temperature-resistance coefficient, 603 is a capacitor,
Reference numerals 604, 605 and 606 denote inverting amplifier circuits, and φclk denotes a clock signal supplied to the microprocessor 601.

In oscillation by a so-called ring oscillator in which an odd number of inverting amplifier circuits are connected, the frequency of the output clock signal is inversely proportional to the product of the resistance component and the capacitance component between the inverting amplifier circuits.

Therefore, in the circuit of FIG. 6, when the temperature of the surface of the microprocessor 601 rises, the resistance value of the resistance temperature detector 602 mounted on the surface increases,
The clock signal φclk drops and the microprocessor 6
The negative feedback control of suppressing the heat generation of 01 is performed to prevent the temperature of the surface of the microprocessor 601 from exceeding the standard value and rising.

[0036]

Second Embodiment In the computer system described in the first embodiment, since the temperature measuring element has to be mounted on the surface of the microprocessor, there is a problem that the assembly work of the product is complicated and the mass production efficiency is deteriorated. is there.

Since the amount of heat generated by a microprocessor is proportional to its power consumption, instead of measuring the temperature of the surface of the microprocessor, the power consumed by the microprocessor is measured and the value of the clock signal supplied to the microprocessor is used. It is also possible to change the frequency and control the temperature of the microprocessor.

FIG. 7 shows an example of the simplest configuration of this embodiment. In FIG. 7, the frequency is controlled by the absolute value of the current consumed by the microprocessor 701.
That is, the value of the consumption current * Ri is compared with the reference voltage Vref to control the frequency of the clock signal φclk.

Although it has been described that the amount of heat generated by the microprocessor is proportional to the power consumption, it is actually proportional to the amount of power, that is, the integrated amount of power over time. Therefore, not only the absolute value of the current as in the example of FIG. 7 but also the control based on the integral amount thereof makes it possible to perform more accurate control.

Needless to say, a strict value is not required to obtain the accumulated power, and a sufficient effect can be expected by a relatively simple means. For example, in FIG. 7, a timer circuit is provided between the comparison operation circuit 702 and the clock signal generation circuit and the frequency control circuit 703, and the clock signal for the microprocessor 701 is provided only when the current value exceeding the reference continuously flows for a certain time. A method of lowering the frequency of φclk may be used.

FIG. 8 shows a configuration that enables more precise control. In FIG. 8, 802 is an operational amplifier (op amp), 803 is an analog-digital conversion circuit,
Reference numeral 804 denotes a counting circuit provided with a reset function.
Indicates a timer circuit that issues an interrupt signal at regular time intervals.

The analog-digital conversion circuit 803 converts the value Vi obtained by converting the current consumption of the microprocessor 801 into a voltage, from the digital value φ1 to φN, and sends it to the count circuit 804. The count circuit 804 has a function of adding these values, and controls the frequency of the clock signal φclk according to the value of the result added within the specified time measured by the timer circuit 805.

Since a one-chip microcomputer incorporating an analog-digital conversion circuit is currently on the market, it is also a good method to use it for the above control.

[0044]

[Third Embodiment] In the first embodiment, the temperature of the microprocessor chip is measured to control the frequency. However, depending on the system configuration, the temperature rise due to the radiation of heat from the microprocessor may adversely affect the peripheral circuits. There is a case to exert. For example, caution is required when an analog circuit that is easily affected by temperature is arranged near the microprocessor.

In such a case, the temperature of the peripheral circuit can be controlled by providing a temperature measuring circuit in the peripheral circuit and controlling the frequency of the clock signal to the microprocessor.

Since the structure of the temperature measuring circuit and the mechanism of temperature control in this embodiment are the same as those described in claim 1 except the mounting location of the temperature measuring element, the description thereof will be omitted here.

Since the temperature measuring element can be mounted on the substrate in measuring the temperature of the peripheral circuit, the computer system of this embodiment is easy to cope with mass production of the product, like the system of the second embodiment. There are also advantages.

The temperature measurement point provided in the peripheral circuit does not have to be limited to one, but it is possible to measure the temperature at a plurality of points and control the frequency of the clock signal to the microprocessor.

It is also possible to perform control by combining the temperature control by the temperature of the microprocessor of the first or second embodiment and the frequency control by the temperature of the peripheral circuit of the present embodiment.

[0050]

Fourth Embodiment Among commercially available microprocessors, there is a product that can be used even when the power supply voltage is lowered below a specified value in order to cope with low power consumption. In general, the power consumption of a semiconductor is proportional to the square of the power supply voltage, so lowering the power supply voltage is very effective in reducing power consumption and heat generation.

In the computer systems described in the first to third embodiments, the heat generation from the microprocessor is suppressed by reducing the frequency of the clock signal supplied to the microprocessor. Since the calculation speed is naturally reduced while the frequency is being reduced to suppress heat generation, it is desirable that this time be as short as possible.

In the system of this embodiment, the value of the power supply voltage supplied to the microprocessor is also reduced at the same time as the frequency is reduced, so that the temperature of the microprocessor or peripheral circuits can be rapidly reduced.

The basic configuration of the computer system in this embodiment is shown in FIG. In FIG. 9, 905 is a voltage control circuit, 906 is a level conversion circuit, 907 is a system peripheral circuit, φvcc is a voltage control signal, Vcpu is a microprocessor 901 and a clock signal generation circuit 9
03 and the drive voltage supplied to the frequency control circuit 904,
φbus1 and φbus2 are microprocessors 90
1 shows a signal group exchanged between 1 and the peripheral circuit 907.

The temperature measuring circuit 902 measures the temperature of the surface of the microprocessor 901 or its surroundings, and when the temperature reaches a predetermined value, the frequency control circuit 90
4 to the frequency control signal φfrq and the voltage control circuit 9
A voltage control signal .phi.vcc is issued to 05.

The frequency control circuit 904, which has received the frequency control signal φfrq, lowers the frequency of the clock signal φclk2 for the microprocessor 901, and similarly receives the voltage control signal φvcc as described in the first to third embodiments. The control circuit 905 reduces the drive voltage Vcpu supplied to the microprocessor 901.

These two control signals may be issued at different specified temperatures or at the same time, but it should be noted that the following points will be given.

In the CMOS integrated circuit, the output resistance increases as the power supply voltage decreases, so that the upper limit of the drive frequency decreases in proportion to the decrease in the power supply voltage. Therefore, it is necessary to control the frequency and the drive voltage within a range that satisfies these relationships.

When the voltage control circuit 905 has a binary voltage control, the simplest method is to selectively output the power supply voltage Vcc and the low voltage generated by a three-terminal regulator or the like. In the case of multi-valued voltage control, control that changes the feedback resistance value of the step-down DC-DC converter, control that uses a commercially available variable output three-terminal regulator, and the like can be considered.

Microprocessor 901 and peripheral circuit 90
7 are connected by many signal lines to exchange information. By controlling the heat generation from the microprocessor 901, the microprocessor 9 is controlled.
When the value of the drive voltage Vcpu supplied to 01 decreases, the potential level of the signal does not match when exchanging information with the peripheral circuit 907, which may cause a data error or the like.

In order to solve this problem, it is necessary to provide a level conversion circuit 906 in the signal line between the microprocessor 901 and the peripheral circuit 907.

An example of the circuit diagram of the level conversion circuit is shown in FIG.
And B. FIG. 10-A shows a level conversion circuit for converting a low-level potential signal into a high-level potential signal. Regardless of whether the input signal φLin having a low level potential is a LOW level signal or a HI level signal, a structure having a positive feedback is provided, and a Vcc level signal φHout having the same logic as the input signal φLin is output.

On the contrary, FIG. 10-B shows a level conversion circuit for converting a high-level potential signal to a low-level potential signal. By removing the diode on the power supply voltage side in the input protection circuit and converting the logic level using only the power supply voltage,
The signal φLout of Vcpu level is output regardless of the potential level of the input signal φHin. Normally, the protection circuit for the internal circuit against the positive excessive current, which is performed by the protection diode on the power supply voltage side, is implemented by using the Zener diodes as the protection diodes 1001 and 1002 on the GND side.

A level conversion circuit for a bidirectional signal such as a data bus combines the above-mentioned two level conversion circuits and enables one circuit by the direction control signal and invalidates the other by changing the direction of the signal. Control.

[0064]

Fifth Embodiment In the computer system described in the fourth embodiment, level conversion circuits must be provided in all signal lines between the microprocessor and the peripheral circuits. There is a cost problem.

In the case of a system in which the peripheral circuit is composed of devices that can be driven at a low voltage, the frequency of the clock signal supplied to the microprocessor is reduced and the power supply voltage of the entire system is reduced when controlling the heat generation. By lowering the level, the same effect as the system of the fourth embodiment can be obtained without the level conversion circuit.

FIG. 1 shows an example of the configuration of the system in this embodiment.
Shown in 1. In FIG. 11, reference numeral 1105 denotes a power circuit.
06 is a power supply source such as a battery or an AC adapter, which is V
bat indicates the supply voltage from the power supply, Vcc indicates the system power supply voltage, and φvcc indicates the power supply voltage control signal.

The temperature measuring circuit 1102 measures the temperature of the surface of the microprocessor 1101 or its surroundings, and when the temperature reaches a predetermined value, it issues a frequency control signal φfreq to the frequency control circuit 1104 and the power supply circuit. Power supply voltage control signal φ for 1105
Issue vcc.

The frequency control circuit 1104 which has received the frequency control signal φfreq lowers the frequency of the clock signal φclk2 to the microprocessor 1101 and has similarly received the voltage control signal φvcc as described in the first to fourth embodiments. The circuit 1105 reduces the system power supply voltage Vcc.

As a means for converting the supply voltage Vbat from the power supply into the system power supply voltage Vcc, a DC-DC converter circuit which can obtain high conversion efficiency is often used.
FIG. 12 shows an example of a DC-DC converter type power supply circuit having a variable output voltage structure.

In FIG. 12, 1201 is a pulse generating circuit, 1202 is a reference potential circuit, and 1203 is a resistance switching circuit. The circuit of FIG. 12 is a step-up DC-D.
This is a C converter circuit, which controls the output voltage to be always constant by dividing the output voltage with a resistor and applying feedback.

The circuit of FIG. 12 further includes a resistance switching circuit 1
203, the output voltage Vcc can be changed by switching the value of the feedback resistor according to the power supply voltage control signal φvcc. Since the resistance switching circuit has been described in claim 1, the description thereof is omitted here.

Further, a method of controlling the value of the power supply voltage Vcc continuously by arranging the feedback resistance portion as a temperature measuring resistance element on or near the surface of the microprocessor is also conceivable.

As another means for changing the power supply voltage Vcc, selective output from two or more voltage sources, control using a commercially available variable output three-terminal regulator, and the like can be considered.

As described in the fourth embodiment, the upper limit of the driving frequency of the microprocessor is also lowered as the driving voltage is lowered. Therefore, the control for reducing the frequency and the power supply voltage is performed within the range satisfying these relationships. There is a need.

[0075]

Sixth Embodiment In order to accurately measure the temperature of the microprocessor in the computer system described in the first embodiment, the temperature measuring element must be mounted on the surface of the microprocessor, which complicates the assembly work of the product. However, there is a problem that the mass production efficiency is deteriorated.

On the other hand, in the computer system described in the second embodiment, the above problem can be avoided, but since the indirect power consumption is the object of measurement, the control accuracy does not reach that of the system of the first embodiment. .

When designing and manufacturing a microprocessor,
By preliminarily incorporating the temperature measuring circuit in the microprocessor chip and providing a terminal for outputting the measurement result to the outside, it is possible to control the temperature suppression of the microprocessor, which solves the above two problems at the same time.

As in the first embodiment, the temperature control circuit built in the microprocessor chip may be a resistance temperature detector, a thermocouple, or the like. Attention must be paid to the following points.

That is, when a comparator and a buffer circuit are incorporated in the chip together with the temperature measuring element in order to output the temperature measurement result to the outside, the pn junctions of these semiconductor circuits all change in voltage due to temperature. That is the point.

Therefore, when the temperature control circuit as described above is incorporated in the microprocessor to control the temperature of the microprocessor as described in the first embodiment, the voltage fluctuation due to the temperature of the semiconductor circuit is also taken into consideration. Although it is necessary to experimentally obtain the control value, there is a risk that the control will not be performed accurately when the temperature change range is large.

In order to avoid such a problem, it is necessary to incorporate only the temperature measuring element in the microprocessor chip or to measure the temperature by a parameter other than the voltage.

A temperature measuring circuit using a ring oscillator as shown in FIG. 13 for changing the frequency is suitable for such an application. In FIG. 13, reference numeral 1301 is a level conversion circuit, 1302 is a frequency dividing circuit, 1303 is a frequency difference circuit, 1304 is a counting circuit, φclk is a reference clock signal, and φthm is a temperature measurement result output to the outside.

Since the oscillation frequency of the ring oscillator has both a relatively large voltage coefficient and a relatively small temperature coefficient, it is necessary to suppress the change in voltage as much as possible when it is used as a temperature measuring circuit. In the circuit of FIG. 13, a bandgap regulator circuit, which is well known as a constant voltage source circuit, is used as the voltage supply source of the ring oscillator to suppress the influence of the fluctuation of the power supply voltage on the ring oscillator.

The temperature coefficient of the oscillation frequency of the ring oscillator is negative when the drive voltage is used in a range higher than the threshold voltage, and conversely, it is positive when used in the range from around the threshold to a lower range. Become. This is because the influence of mobility on the temperature becomes higher at a voltage higher than the threshold, and the influence on the temperature of the threshold becomes stronger near the threshold and below.

In order to detect a change in frequency due to temperature, a reference frequency is required. Fortunately, there is a clock signal created by the oscillation of a crystal oscillator in a computer system. The clock signal generated by the oscillation of the crystal oscillator has a change in frequency due to temperature of the order of 10 −5 to −6, and is therefore suitable for use as a frequency reference.

It should be noted that, in the computer system of the present invention, the microprocessor drive clock signal cannot be used as the reference clock signal because the frequency changes due to the temperature suppression control. It is necessary to input a clock signal whose frequency in the system does not change, for example, a source clock signal of a driving clock signal, into the microprocessor chip and use it as the reference clock signal φclk.

In the circuit of FIG. 13, the clock signal oscillated by the ring oscillator is level-shifted and divided to have a frequency on the order of the reference clock signal, and then compared with the reference frequency φclk in the frequency difference circuit 1303. To be done. As a structure of the frequency difference circuit 1303, two inputs are passed through an AND circuit or an OR circuit, and the high frequency component of the output is cut by a low pass filter, so that the difference in frequency between the two input clock signals is obtained.

By measuring the difference signal thus obtained by the counting circuit, the temperature change can be measured, the measurement result signal φthm is output to the outside of the chip, and the frequency of the clock signal similar to that described in the first embodiment is used. By performing the control, the temperature suppression control of the microprocessor becomes possible.

The circuit shown in FIG. 13 is quite large if it is composed of a single component, but by incorporating it in a chip together with a microprocessor, special elements such as a resistance temperature detector and a thermocouple are built in the chip. than,
On the contrary, both cost and area can be kept low.

[0090]

Seventh Embodiment In the sixth embodiment, the microcomputer integrated circuit in which the temperature measuring circuit is built in the chip has been described. However, since a frequency control circuit is also built in, no external parts are required, and the embodiment is described. It becomes possible to control the temperature of such a microprocessor.

The basic configuration of this embodiment is shown in FIG. Figure 1
4 in 1 is a microprocessor chip 1
Reference numeral 402 denotes a microprocessor circuit, 1403 denotes a temperature measurement circuit built in the microprocessor chip, 14
04 is a frequency control circuit built in the chip, 1405
Is a clock signal generation circuit, φclk1 is a source clock signal supplied to the microprocessor chip 1401,
φclk2 indicates a drive clock signal supplied to the microprocessor unit 1402, φfreq indicates a frequency control signal, and φcnt indicates a frequency control permission signal.

The microprocessor integrated circuit shown in FIG.
The temperature control circuit 1403 is the microprocessor chip 14
The temperature control circuit 1404 measures the temperature 01, and the frequency control circuit 1404 changes the frequency of the clock signal φclk2 supplied to the microprocessor circuit 1402 to suppress the temperature rise of the microprocessor chip 1401 described in the first embodiment. Is provided by the integrated circuit itself without any external signal.

Therefore, by using the microprocessor of this embodiment, the system designer can design the system without paying attention to the problem of heat generation from the microprocessor.

For a purpose such as always using the microprocessor at the highest frequency, by enabling or prohibiting the operation of the frequency control circuit 1404 by a signal φcnt from the outside, a more flexible system can be realized. Correspondence becomes possible.

[0095]

Eighth Embodiment In the seventh embodiment, the microcomputer integrated circuit in which the temperature measuring circuit and the frequency control circuit are built in the chip has been described. However, by incorporating the voltage control circuit and the level conversion circuit, external parts are unnecessary. Then, the temperature control of the microprocessor as described in the fourth embodiment becomes possible.

The basic structure of this embodiment is shown in FIG. In FIG. 15, 1504 is a voltage control circuit, and 1506 and 1
Reference numerals 507 and 1510 denote level conversion circuits, respectively.

The microprocessor shown in FIG. 15 has a structure in which the frequency of the clock signal φclk2 and the value of the drive voltage Vcpu are changed according to the temperature of the chip, and control for preventing an abnormal rise in the temperature of the chip is performed without an external signal. Prepare The details of the temperature control have already been described in the fourth embodiment, and therefore the description thereof will be omitted here.

For the purpose such as always using the microprocessor at the highest frequency, the structure in which the permission / prohibition of the operations of the voltage control circuit 1504 and the frequency control circuit 1505 can be controlled by external signals φVcnt and φFcnt is provided. , It becomes possible to support a more flexible system.

[0099]

As described above, according to the computer system of the present invention, the temperature of the microprocessor abnormally rises beyond the rated value while maintaining a high calculation performance without using a large heat sink or an air cooling fan. It is possible to prevent this.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a system according to a first embodiment.

FIG. 2 is a schematic diagram when a temperature measuring element is attached to the surface of a microprocessor.

FIG. 3 is a configuration example of a system in the first embodiment.

FIG. 4 is an example of a temperature measurement circuit and a frequency control circuit in the first embodiment.

FIG. 5 is a configuration example of a system in the first embodiment.

FIG. 6 is a configuration example of a system in the first embodiment.

FIG. 7 is a configuration example of a system according to a second embodiment.

FIG. 8 is a configuration example of a system in the second embodiment.

FIG. 9 is a basic configuration diagram of a system in a fourth embodiment.

FIG. 10 is an example of a level conversion circuit according to the fourth embodiment.

FIG. 11 is a basic configuration diagram of a system according to a fifth embodiment.

FIG. 12 is an example of a power supply circuit according to a fifth embodiment.

FIG. 13 is an example of a temperature measurement circuit according to the sixth embodiment.

FIG. 14 is a basic configuration diagram of an integrated circuit according to a seventh embodiment.

FIG. 15 is a basic configuration diagram of an integrated circuit according to an eighth embodiment.

[Explanation of symbols]

 101 Microprocessor 102 Temperature Measurement Circuit 103 Clock Signal Generation Circuit 104 Frequency Control Circuit φclk1 Source Clock Signal φclk2 Microprocessor Drive Clock Signal φfreq Frequency Control Signal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiko Sato 840 Takeno, Shimotomi, Tokorozawa, Saitama Prefecture Citizen Watch Co., Ltd.

Claims (8)

[Claims] 1. A microprocessor and a circuit for generating a clock signal for driving the microprocessor,
And a computer system including peripheral circuits,
Further, a means for measuring the temperature of the surface of the microprocessor chip and a means for changing the frequency of the clock signal supplied to the microprocessor are provided, and the clock signal supplied to the microprocessor according to the temperature of the surface of the microprocessor chip during system operation. And a structure for preventing the temperature of the microprocessor chip from rising above a specified value by changing the frequency of the computer system. 2. A microprocessor and a circuit for generating a clock signal for driving the microprocessor,
And a computer system including peripheral circuits,
Further, a means for measuring the power consumed by the microprocessor and a means for changing the frequency of the clock signal supplied to the microprocessor are provided, and the clock signal supplied to the microprocessor by the power consumption of the microprocessor during system operation. And a structure for preventing the temperature of the microprocessor chip from rising above a specified value by changing the frequency of the computer system. 3. A microprocessor and a circuit for generating a clock signal for driving the microprocessor,
And a computer system including peripheral circuits,
Further, it is provided with means for measuring the temperature around the microprocessor and means for changing the frequency of the clock signal supplied to the microprocessor, and the frequency of the clock signal supplied to the microprocessor depends on the temperature around the microprocessor during system operation. And a structure for preventing the temperature around the microprocessor from rising above a specified value by changing the temperature. 4. The computer system according to claim 1, 2, or 3, further comprising means for changing a power supply voltage supplied to the microprocessor and a level conversion circuit on a signal line between the microprocessor and the peripheral circuit. Provided, during system operation, the frequency of the clock signal supplied to the microprocessor and the power supply voltage supplied to the microprocessor are changed depending on the temperature around the microprocessor chip or the microprocessor or the power consumption of the microprocessor, A computer system having a structure for preventing a temperature of a microprocessor chip or the periphery of the microprocessor from exceeding a specified value and rising. 5. The computer system according to claim 1, 2 or 3, further comprising means for changing the power supply voltage of the entire system, wherein the temperature of the microprocessor chip or the periphery of the microprocessor or the microprocessor during operation of the system. Depending on the power consumption of the processor, the frequency of the clock signal supplied to the microprocessor and the power supply voltage of the entire system are changed,
A computer system having a structure for preventing a temperature of a microprocessor chip or the periphery of the microprocessor from exceeding a specified value and rising. 6. A microprocessor integrated circuit having a built-in temperature measurement circuit and having an external terminal for outputting a measurement result, wherein the microprocessor internal temperature is measured during operation, and the measurement result is output to the external terminal. A microprocessor integrated circuit having a structure for outputting. 7. A microprocessor integrated circuit having a temperature measuring circuit and a circuit for converting the frequency of a drive clock signal supplied from the outside and supplying the converted clock signal to the inside of the microprocessor. A microstructure characterized by including a structure for performing measurement and changing the frequency of a drive clock signal supplied to the inside of the microprocessor according to the temperature to prevent the temperature inside the microprocessor from rising above a specified value. Processor integrated circuit. 8. The microprocessor integrated circuit according to claim 7, further comprising a circuit for changing the power supply voltage supplied from the outside to supply the power to the inside of the microprocessor, and a signal from an internal circuit driven by the changed voltage. Has a built-in level conversion circuit that converts the voltage to an external power supply voltage level, measures the internal temperature of the microprocessor during operation, and the frequency of the drive clock signal supplied to the inside of the microprocessor according to the temperature and the power supply voltage supplied to the inside. And a structure for performing a control for preventing the temperature inside the microprocessor from rising beyond a predetermined value by changing the temperature.