JPH0561573A - Information processor and power supply control method - Google Patents

Information processor and power supply control method

Info

Publication number
JPH0561573A
JPH0561573A JP3222563A JP22256391A JPH0561573A JP H0561573 A JPH0561573 A JP H0561573A JP 3222563 A JP3222563 A JP 3222563A JP 22256391 A JP22256391 A JP 22256391A JP H0561573 A JPH0561573 A JP H0561573A
Authority
JP
Japan
Prior art keywords
external device
power supply
supply control
serial interface
interface circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP3222563A
Other languages
Japanese (ja)
Inventor
Makoto Kukida
真 久木田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP3222563A priority Critical patent/JPH0561573A/en
Publication of JPH0561573A publication Critical patent/JPH0561573A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To reduce the energy consumption of a portable personal computer or the like by judging whether the information processor is electrically connected to an external device or not and operating a serial interface circuit only when a power source is turned on. CONSTITUTION:An information processor 10 is equipped with a power supply control part 17 to detect whether the level of a received data signal from an external device 18 exceeds a prescribed threshold value or not and to execute ON/OFF control for the power source of a serial interface circuit 12 according to the result and when the external device 18 is not made active by a power supply control signal line, the power source of the serial interface circuit 12 is turned off.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、携帯用パーソナルコン
ピュータ(パソコン)等の情報処理装置およびその電源
制御方法に関し、特にシリアルインタフェース回路の電
源を効率的に制御することにより、消費電力の低減をは
かる情報処理装置および電源制御方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus such as a portable personal computer (personal computer) and a power supply control method therefor, and more particularly, to efficiently reduce the power consumption of a serial interface circuit. The present invention relates to a scalable information processing device and a power supply control method.

【0002】[0002]

【従来の技術】携帯用のパソコンの普及により、コンピ
ュータ機器の電池による動作時間を延ばすことが要求さ
れている。このため、CPUや周辺デバイスに対する供
給クロックを使用しない場合、あるいは高速で動作する
必要のない場合には、最大周波数より小さい周波数を用
いたり、電源をOFFとしたりする方法が採用されてい
る。さらに、このような方法を実行する際、CPUの処
理時間が増加することを防ぐため、CPUバス上に電力
制御装置を配置して、キー入力を常時センスし、所定時
間内にキー入力が検出されない場合には、バスの制御権
を得て、制御信号等によりパワーダウンモードへ移行さ
せ、キー入力を検出した時点で通常モードに戻して、バ
ス制御権を放棄する方法も提案されている。また、従来
の携帯用パーソナルコンピュータでは、受信データ信号
線以外の信号線を用いて外部装置の状態を伝えているた
め、直ちに通信できる状態にあるか否かを判別すること
は可能だが、電気的に接続されているか否かを判別する
ことはできない。なお、この種の方法として関連するも
のには、例えば、特願平2−179078号がある。
2. Description of the Related Art With the widespread use of portable personal computers, it has been required to extend the operating time of batteries in computer equipment. Therefore, when the supply clock to the CPU or peripheral devices is not used, or when it is not necessary to operate at high speed, a method of using a frequency smaller than the maximum frequency or turning off the power is adopted. Further, when performing such a method, in order to prevent the CPU processing time from increasing, a power control device is arranged on the CPU bus to constantly sense the key input and detect the key input within a predetermined time. If not, a method of relinquishing the bus control right is proposed in which the bus control right is obtained, the power down mode is shifted to the power down mode by a control signal or the like, and the mode is returned to the normal mode when a key input is detected. Further, in the conventional portable personal computer, since the state of the external device is transmitted by using a signal line other than the received data signal line, it is possible to immediately determine whether or not the state is ready for communication, but the electrical It is not possible to determine whether or not it is connected to. As a method related to this type, there is, for example, Japanese Patent Application No. 2-179078.

【0003】[0003]

【発明が解決しようとする課題】上記従来技術では、外
部装置が直ちに通信可能な状態にあるか否かの検出は可
能であるが、電気的に接続されているか否かの判定は不
可能であるため、省力化(消費電力の低減)をより進め
ることは難しかった。本発明の目的は、外部装置と電気
的に接続されているか否かを判定して、電源ONの場合
のみシリアルインタフェース回路を動作させることによ
り、このような問題点を改善して、消費電力を低減させ
るのに好適な情報処理装置および電源制御方法を提供す
ることにある。
According to the above-mentioned prior art, it is possible to detect whether or not the external device is immediately in the communicable state, but it is impossible to judge whether or not the external device is electrically connected. Therefore, it was difficult to further promote labor saving (reduction of power consumption). An object of the present invention is to improve such problems and to reduce power consumption by determining whether or not an external device is electrically connected and operating the serial interface circuit only when the power is turned on. An object of the present invention is to provide an information processing apparatus and a power supply control method suitable for reducing the power consumption.

【0004】[0004]

【課題を解決するための手段】上記目的を達成するた
め、本発明の電源制御方法は、外部装置からの受信デー
タ信号のレベルが所定しきい値を超えるか否かによっ
て、その外部装置が活性状態にあるか否かを検出し、外
部装置が活性状態にない場合には、電源制御信号を用い
てシリアルインタフェース回路の電源をOFFすること
に特徴がある。また、本発明の情報処理装置は、受信デ
ータ信号線、シリアルインタフェース回路、および外部
装置との接続手段に加えて、外部装置からの受信データ
信号のレベルが所定しきい値を超えるか否かを検出する
手段(電源制御部)と、その結果によってシリアルイン
タフェース回路の電源をON/OFF制御する手段(電
源制御信号線を含む電源制御部)とを設けたことに特徴
がある。
In order to achieve the above object, the power supply control method of the present invention is to activate an external device depending on whether or not the level of a received data signal from the external device exceeds a predetermined threshold value. It is characterized by detecting whether or not it is in the state, and when the external device is not in the active state, the power of the serial interface circuit is turned off by using the power control signal. Further, the information processing device of the present invention determines whether or not the level of the received data signal from the external device exceeds a predetermined threshold value, in addition to the reception data signal line, the serial interface circuit, and the connection means with the external device. It is characterized in that a means for detecting (power supply control section) and a means for controlling ON / OFF of the power supply of the serial interface circuit (power supply control section including a power supply control signal line) according to the result are provided.

【0005】[0005]

【作用】本発明においては、電圧検出回路、アドレスデ
コーダ、バスバッファ等から構成された電源制御池部に
より、外部装置からの受信データ信号のレベルを検出す
る。そして、検出した電圧がバスバッファの所定しきい
値(VTH2)より低い場合には、外部装置は活性状態に
ないものとし、電源制御信号を用いてシリアルI/F回
路の電源をOFFにする。これにより、外部装置が接続
されていない時間、あるいは電源がOFFとなっている
時間は、電力を供給せずに済むため、低消費電力の携帯
用情報処理装置を実現できる。
According to the present invention, the level of the received data signal from the external device is detected by the power supply control pond section composed of the voltage detection circuit, the address decoder, the bus buffer and the like. If the detected voltage is lower than the predetermined threshold value (VTH2) of the bus buffer, the external device is not activated and the power supply control signal is used to turn off the power supply of the serial I / F circuit. As a result, it is not necessary to supply electric power when the external device is not connected or when the power is off, so that a low power consumption portable information processing device can be realized.

【0006】[0006]

【実施例】以下、本発明の一実施例を図面により説明す
る。図1は、本発明の一実施例における情報処理装置の
構成図、図2は本発明の一実施例における電源制御に用
いる信号のタイミングチャートである。図1において、
11は装置全体を制御するCPU、12はシリアルイン
タフェース(I/F)回路、16はCPUバス、17は
電源制御部、21はシリアルI/F回路12用の電源制
御信号線であり、これらが本実施例の情報処理装置(携
帯用パソコン等)を構成する。また、13はアドレスデ
コーダ、14は電圧検出回路、15はバスバッファであ
り、これらは電源制御部17に含まれる。さらに、18
はI/Fケーブル19およびI/Fコネクタ20によっ
て情報処理装置10と接続される外部装置である。本実
施例のCPU11は、アドレスデコーダ13がONとな
るアドレスを読み出すことにより、外部装置18の動作
状態を読み取る。また、バスバッファ15は、電圧検出
回路14を介して得られた受信データの信号レベルを示
す信号(位置)とアドレスデコーダ13の出力とのA
NDをとり、その出力(位置)によって、CPU11
に外部装置18の動作状態を知らせる。また、電源制御
信号線21は、外部装置18電源のON/OFF状態に
よって、シリアルI/F回路12の電源を制御するため
のものである。
DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an information processing apparatus in one embodiment of the present invention, and FIG. 2 is a timing chart of signals used for power supply control in one embodiment of the present invention. In FIG.
Reference numeral 11 is a CPU for controlling the entire apparatus, 12 is a serial interface (I / F) circuit, 16 is a CPU bus, 17 is a power supply control unit, 21 is a power supply control signal line for the serial I / F circuit 12, and these are The information processing apparatus (portable personal computer or the like) of this embodiment is configured. Further, 13 is an address decoder, 14 is a voltage detection circuit, and 15 is a bus buffer, which are included in the power supply controller 17. In addition, 18
Is an external device connected to the information processing device 10 by the I / F cable 19 and the I / F connector 20. The CPU 11 of the present embodiment reads the operating state of the external device 18 by reading the address at which the address decoder 13 turns ON. Further, the bus buffer 15 receives the signal (position) indicating the signal level of the received data obtained via the voltage detection circuit 14 and the output of the address decoder 13 from A.
ND is taken, and the CPU 11 is determined by its output (position).
To notify the operating state of the external device 18. The power supply control signal line 21 is for controlling the power supply of the serial I / F circuit 12 depending on the ON / OFF state of the power supply of the external device 18.

【0007】ここで、図2により、外部装置18の動作
状態を検出する方法について述べる。なお、本実施例で
は、受信データ信号は無通信時(外部装置18が電源O
N状態で、情報処理装置10と通信していない場合)
は、V(−)のレベルを保つものとする。例えば、受信
データ信号のレベル(以下Vrと記す)が、RLにより
GNDにほぼ近いものとなっている状態から、外部装置
18の電源が時刻T0で入った場合、位置におけるV
rは、徐々に下降する。そして、電圧検出回路14のし
きい値VTH1を過ぎると、位置における電圧は「L」
となり、コンデンサ(C)の電荷がダイオード(Di)
を通して放電される。これにより、Cの電圧は低下し、
時刻T1において、「VTH2(バスバッファ15のしきい
値)>Cの電圧」となる。この後、時刻T2で外部装置
18の電源が切れたとすると、Vrは、GNDレベルに
向けて上昇する。そして、「VTH1<Vr」となる時刻T
3において、位置における電圧は「H」となり、Cは
Rを通して充電されるため、時刻T4では、「Cの電圧
>VTH2」となって、位置およびにおける電圧は
「H」となる。こうして検出した信号(位置)によ
り、シリアルI/F回路12の電源のON/OFFを制
御する。つまり、外部装置18の動作期間中はON、そ
れ以外はOFFとする。なお、時刻T1からT4の間に、
受信データによりCの電圧がVTH2を超えないために
は、CRの時定数が受信データ1ワードのスタートビッ
トからストップビットまでの時間よりも大きければよ
い。また、本実施例では、バスバッファ15から読み出
した結果が「L」となっている時間(時刻T1からT4
で)を外部装置18の動作期間として検出するが、この
うち、外部装置18の電圧が降下する時間(時刻T2
らT3まで)、およびCRの時定数で定まる時間(時刻
3からT4までであり、受信データ1ワードより僅かに
長い程度)は無視できるので、この検出時間は、外部装
置18の動作時間(時刻T1からT2まで)とほぼ等しい
ものである。
A method of detecting the operating state of the external device 18 will be described with reference to FIG. In the present embodiment, the received data signal is not transmitted when the external device 18 is powered
(When not communicating with the information processing device 10 in the N state)
Holds the level of V (−). For example, when the power of the external device 18 is turned on at time T 0 from the state where the level of the received data signal (hereinafter referred to as Vr) is close to GND due to RL, V at the position
r gradually falls. When the voltage VTH1 of the voltage detection circuit 14 is exceeded, the voltage at the position is "L".
And the electric charge of the capacitor (C) becomes the diode (Di).
Be discharged through. As a result, the voltage of C decreases,
At time T 1 , “VTH2 (threshold value of bus buffer 15)> voltage of C” is satisfied. After that, if the external device 18 is powered off at time T 2 , Vr rises toward the GND level. Then, the time T when “VTH1 <Vr” is satisfied.
At 3 , the voltage at position is “H” and C is charged through R, so at time T 4 , “voltage of C> VTH2”, and the voltage at position and is “H”. The signal (position) thus detected controls ON / OFF of the power supply of the serial I / F circuit 12. That is, it is turned on during the operation period of the external device 18, and turned off at other times. In addition, between time T 1 and T 4 ,
In order that the voltage of C does not exceed VTH2 by the received data, the time constant of CR may be larger than the time from the start bit to the stop bit of one word of the received data. In addition, in the present embodiment, the time when the result read from the bus buffer 15 is “L” (from time T 1 to T 4 ) is detected as the operation period of the external device 18. The voltage drop time (from time T 2 to T 3 ) and the time determined by the time constant of CR (from time T 3 to T 4 , which is slightly longer than one word of received data) can be ignored. This detection time is almost equal to the operation time of the external device 18 (from time T 1 to T 2 ).

【0008】[0008]

【発明の効果】本発明によれば、外部装置が活性状態に
あるか否かを検出することができる。また、この検出結
果を用いてシリアルI/F回路の電源を制御することに
より、通信が行われる恐れのない間(外部装置が接続さ
れていない時間、あるいは外部装置の電源がOFFとな
っている時間)は、電源をOFFできるので、低消費電
力の情報処理装置を実現することが可能である。さら
に、受信データ信号のみを用いて外部装置の活性状態を
検出することができるので、受信データ、送信データ、
およびGND用の3本の信号線しかない通信方法に利用
することも可能である。
According to the present invention, it is possible to detect whether or not the external device is in the active state. Further, by controlling the power supply of the serial I / F circuit by using the detection result, there is no fear of communication (when the external device is not connected or the power supply of the external device is turned off). (Time), the power can be turned off, so that an information processing device with low power consumption can be realized. Furthermore, since it is possible to detect the active state of the external device using only the received data signal, the received data, the transmitted data,
Also, it can be used for a communication method having only three signal lines for GND.

【0009】[0009]

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例における情報処理装置の構成
図である。
FIG. 1 is a configuration diagram of an information processing apparatus according to an embodiment of the present invention.

【図2】本発明の一実施例における電源制御に用いる信
号のタイミングチャートである。
FIG. 2 is a timing chart of signals used for power supply control in one embodiment of the present invention.

【符号の説明】[Explanation of symbols]

10 情報処理装置 11 CPU 12 シリアルI/F回路 13 アドレスデコーダ 14 電圧検出回路 15 バスバッファ 16 CPUバス 17 電源制御部 18 外部装置 19 I/Fケーブル 20 I/Fコネクタ 21 電源制御信号線 10 information processing device 11 CPU 12 serial I / F circuit 13 address decoder 14 voltage detection circuit 15 bus buffer 16 CPU bus 17 power supply control unit 18 external device 19 I / F cable 20 I / F connector 21 power supply control signal line

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 外部装置と接続された情報処理装置にお
けるシリアルインタフェース回路の電源制御方法におい
て、外部装置からの受信データ信号のレベルが所定しき
い値を超えるか否かにより、該外部装置が活性状態にあ
るか否かを検出することを特徴とする電力制御方法。
1. A power control method for a serial interface circuit in an information processing device connected to an external device, wherein the external device is activated depending on whether or not the level of a received data signal from the external device exceeds a predetermined threshold value. A power control method characterized by detecting whether or not there is a state.
【請求項2】 上記検出の結果を示す制御信号を用い、
外部装置が活性状態にない場合には、シリアルインタフ
ェース回路の電源をOFFすることを特徴とする請求項
1記載の電源制御方法。
2. Using a control signal indicating the result of the detection,
2. The power supply control method according to claim 1, wherein the power supply of the serial interface circuit is turned off when the external device is not in the active state.
【請求項3】 受信データ信号線、シリアルインタフェ
ース回路、および外部装置との接続手段を備えた情報処
理装置において、外部装置からの受信データ信号のレベ
ルが所定しきい値を超えるか否かを検出する手段と、該
検出の結果によってシリアルインタフェース回路の電源
をON/OFF制御する手段とを設けたことを特徴とす
る情報処理装置。
3. An information processing device comprising a received data signal line, a serial interface circuit, and a connection means for connecting to an external device, and detects whether or not the level of the received data signal from the external device exceeds a predetermined threshold value. An information processing device, comprising: a means for controlling the power supply of the serial interface circuit according to the result of the detection.
JP3222563A 1991-09-03 1991-09-03 Information processor and power supply control method Pending JPH0561573A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3222563A JPH0561573A (en) 1991-09-03 1991-09-03 Information processor and power supply control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3222563A JPH0561573A (en) 1991-09-03 1991-09-03 Information processor and power supply control method

Publications (1)

Publication Number Publication Date
JPH0561573A true JPH0561573A (en) 1993-03-12

Family

ID=16784423

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3222563A Pending JPH0561573A (en) 1991-09-03 1991-09-03 Information processor and power supply control method

Country Status (1)

Country Link
JP (1) JPH0561573A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06342329A (en) * 1993-05-18 1994-12-13 Nec Corp Peripheral controller
JP2008262393A (en) * 2007-04-12 2008-10-30 Matsushita Electric Ind Co Ltd Information processing system and its control method
JP2009213868A (en) * 2008-03-07 2009-09-24 Ge Medical Systems Global Technology Co Llc Docking station and ultrasonic diagnosing system
US8949634B2 (en) 2008-04-25 2015-02-03 Fujitsu Limited Storage device connected to a superior device and method of supplying power to the storage device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06342329A (en) * 1993-05-18 1994-12-13 Nec Corp Peripheral controller
JP2008262393A (en) * 2007-04-12 2008-10-30 Matsushita Electric Ind Co Ltd Information processing system and its control method
JP2009213868A (en) * 2008-03-07 2009-09-24 Ge Medical Systems Global Technology Co Llc Docking station and ultrasonic diagnosing system
US8949634B2 (en) 2008-04-25 2015-02-03 Fujitsu Limited Storage device connected to a superior device and method of supplying power to the storage device

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