JPH113132A - Power management device - Google Patents

Abstract

(57) [Summary] In power management control, a low-frequency control using a low-voltage control accompanying a shift to a low frequency is performed only by controlling the frequency of lowering the frequency or stopping the operation of the clock for a certain period of time. Reduce power consumption. When a frequency is reduced by power management control, a switching time is lengthened with a reduction in frequency to reduce noise, limit a rise in temperature, and the like, and set an operating voltage low to an operable range. This will further reduce the specific power at low places.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to controlling power management processing by lowering the power supply voltage as the operating frequency is lowered by power management control. About.

[0002]

2. Description of the Related Art Conventionally, to change the operating frequency by power management control, a method of lowering the frequency or stopping the operation of the clock for a certain period is adopted. As a result, the operating rate is reduced, and power consumption is reduced.

[0003] This type of technology is disclosed in, for example, Japanese Patent Application Laid-Open No.
No. 628.

[0004]

In the prior art, low power consumption using low voltage control accompanying a shift to a low frequency is not performed only by controlling the frequency.

[0005]

According to the present invention, when the frequency is reduced by the conventional power management control, the switching time is extended along with the lower frequency to reduce noise and limit the temperature rise. Set the operating voltage low to the operable range.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail. FIG. 1 is a schematic diagram of frequency and voltage control. FIG. 2 is an operation waveform diagram of the constant voltage circuit. FIG. 3 is a configuration diagram of a constant voltage circuit and each voltage to be controlled. FIG.
FIG. 3 is a configuration diagram of voltage control of a functional circuit in a constant voltage circuit.

Next, a method of frequency and voltage control in FIG. 1 will be described.

[0008] The constant voltage circuit FVC0 includes a voltage control unit PVC.
The voltage Vout supplied to 1 is converted into a voltage, and the output voltage Vout is used as a constant voltage to output a pulse signal of a constant frequency. Further, the constant voltage circuit FVC0 has a frequency control unit PFC as a conventional power management control.
The frequency is set low by receiving the frequency suppression signal Ctrl-F from. Constant voltage circuit FVC0 suppressed to low frequency
Since the operating voltage has a margin due to the reduction of noise and the restriction of temperature rise, the frequency control unit PFC controls the voltage control unit PV to reduce the voltage to an operable voltage value in the present invention.
The voltage suppression signal Ctrl-V is sent to C1. Further, in the present invention, the rate of voltage suppression by the voltage suppression signal Ctrl-V is changed by the difference in frequency value by the frequency suppression signal Ctrl-F, and when the frequency is turned off during a certain period, the voltage output from the voltage control unit PVC1 is changed. Stop.

Next, operation waveform control in the constant voltage circuit of FIG. 2 will be described.

In a normal operation state of the constant voltage circuit FVC0, as shown in a waveform 1, an amplitude voltage VLT1 and a pulse width PLS
1, the frequency suppression signal Ctrl-
The pulse width of PLS2 (> P
LS1) and low frequency operation. Furthermore, constant voltage circuit FVC
The waveform of 0 is the waveform 3 by the voltage suppression signal Ctrl-V.
, The amplitude voltage becomes as low as VLT2 (> VLT1).

Since the switching time indicates the slope of the amount of time change of the voltage expressed by dV / dt, the voltage changes when the frequency is controlled by delay control when transitioning from waveform 1 to waveform 2 in FIG. The time becomes longer, the inclination of the pulse waveform is reduced, and the switching time becomes longer.

Further, when transitioning from waveform 2 to waveform 3, the amount of change in voltage is reduced, so that the slope is further alleviated, the switching time is lengthened, and the possibility of erroneous operation is reduced even when operated at a low voltage. .

Next, the configuration and control of each constant voltage circuit and voltage shown in FIG. 3 will be described.

The voltage control unit PVC supplied with the voltage Vin
1 to each constant voltage circuit, the voltages VoutC1, VOutC2, VoutC3 of the same voltage and the voltages VoutA, VoutB of different voltages are converted and output in a steady state. Each voltage is set by the voltage control unit PVC1 as to whether or not to be suppressed by the pattern of the voltage suppression signal Ctrl-V and to what extent the voltage is to be suppressed.

Usually, circuits having different voltages (for example, FVC
In the present invention, the voltage control unit PVC1 used to separate the voltage control circuit 1 from the voltage control circuit FVC2 and the voltage control circuit FVC2 is separated from each other by a constant voltage circuit (for example, FV2) having different voltage suppression methods or different voltage suppression amounts.
C3, FVC4 and FVC5) also separate the circuit.

Next, voltage control of a functional circuit in the constant voltage circuit of FIG. 4 will be described.

Each of the functional circuits CirA and CirB is a part of a constant voltage circuit (for example, FVC2 in FIG. 2) and includes voltage control circuits PVC2 and PV2 existing in the same constant voltage circuit.
The voltage is suppressed by C3. Voltage control circuit PVC2
And PVC3 are supplied in the same manner as the voltage supplied to the constant voltage circuit, and suppress the supply voltages V1 and V2 to the functional circuits CirA and CirB by the voltage suppression signal Ctrl-V. The function circuits CirA and CirB are suppressed in voltage more than the constant voltage circuit itself is suppressed in voltage.

[0018]

According to the present invention, the power consumption can be further reduced by lowering the operating voltage when the operating frequency is lowered.

For example, when the operating frequency is set to 50% and the operating voltage is set to 90%, the power consumption becomes about 4 by the following equation.
It can be 0%.

P = CV ² fα (where P: power consumption, C: capacitance, V: voltage,
f: operating frequency, α: activation rate)

[Brief description of the drawings]

FIG. 1 is a schematic diagram of frequency and voltage control.

FIG. 2 is an operation waveform diagram of a constant voltage circuit.

FIG. 3 is a configuration diagram of a control voltage of a constant voltage circuit.

FIG. 4 is a voltage control diagram of a functional circuit in a constant voltage circuit.

[Explanation of symbols]

Vin: voltage supplied to the voltage control unit, Vout: voltage converted by the voltage control unit and supplied to the constant voltage circuit, P
VC1 to PVC3: voltage control units for performing voltage conversion control;
PFC: Frequency control unit, Ctrl-V: Voltage suppression signal for changing the voltage conversion amount of the voltage control unit, Ctrl-F:
A frequency suppression signal that changes the operating frequency of the constant voltage circuit,
FVC0 to FVC5 ... constant voltage circuit, VLT1 to VLT
2 ... SMl illegal processing, PLS1 to PLS2 ... lr key device, VoutA, VoutB, VoutC1 to Vo
utC3: Supply voltage to constant voltage circuit, V1 to V2: Supply voltage to functional circuit.

Claims (1)

[Claims] 1. A pulse output circuit for outputting a pulse signal of a predetermined frequency, a low frequency operation transition circuit for outputting a signal for lowering the pulse frequency of the predetermined frequency, and a low frequency transition instruction circuit circuit for low frequency operation A power management device comprising voltage control means for reducing an output voltage of a pulse output from the pulse output circuit in accordance with the shift.