JPH03130885A - Microcomputer - Google Patents
MicrocomputerInfo
- Publication number
- JPH03130885A JPH03130885A JP1270890A JP27089089A JPH03130885A JP H03130885 A JPH03130885 A JP H03130885A JP 1270890 A JP1270890 A JP 1270890A JP 27089089 A JP27089089 A JP 27089089A JP H03130885 A JPH03130885 A JP H03130885A
- Authority
- JP
- Japan
- Prior art keywords
- power supply
- supply voltage
- rom
- prom
- signal
- 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
Links
- 238000001514 detection method Methods 0.000 claims abstract description 27
- 101100521334 Mus musculus Prom1 gene Proteins 0.000 description 17
- 230000000694 effects Effects 0.000 description 3
- 101150065817 ROM2 gene Proteins 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 101000610551 Homo sapiens Prominin-1 Proteins 0.000 description 1
- 102100040120 Prominin-1 Human genes 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D10/00—Energy efficient computing, e.g. low power processors, power management or thermal management
Landscapes
- Read Only Memory (AREA)
- Retry When Errors Occur (AREA)
- Memory System (AREA)
- Power Sources (AREA)
- Techniques For Improving Reliability Of Storages (AREA)
- Microcomputers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はマイクロコンピュータに関し、特にＰＲＯＭを
内蔵したマイクロコンピュータに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microcomputer, and particularly to a microcomputer incorporating a PROM.
従来、マイクロコンピュータは、命令などのデータを格
納するために読み出し専用メモリー（以下ＲＯＭとする
）を内蔵するものがある。しかし、１チツプで構成する
マイクロコンピュータ等においては、ＲＯＭの内容が製
造段階で格納されるため、製品ができあがってからＲＯ
Ｍの内容を変えることができなかった。このため、製品
ができあがってからＲＯＭの内容が変えられるような電
気的書き込み可能読み出し専用メモリー（以下ＰＲＯＭ
とする）を１チツプ上にＲＯＭと共に内蔵するものがあ
る。Conventionally, some microcomputers include a read-only memory (hereinafter referred to as ROM) for storing data such as instructions. However, in the case of microcomputers constructed with one chip, the contents of the ROM are stored at the manufacturing stage, so the ROM is stored only after the product is completed.
It was not possible to change the contents of M. For this reason, electrically writable read-only memory (hereinafter referred to as PROM) is a ROM whose contents can be changed after the product is completed.
Some devices have a ROM built-in on one chip.
ＰＲＯＭは一般に通常のＲＯＭを含む論理回路よりも、
動作電源電圧の最低限界（以下最低動作電源電圧とする
）が高い、従って、上述した従来のＰＲＯＭ内蔵マイク
ロコンピュータでは最低動作電源電圧がＰＲＯＭの動作
できまる高めの電圧に設定されていた。しかしながら、
例えば、電源電圧が下がり、ＰＲＯＭの最低動作電源電
圧となっていても、他のＲＯＭ等の論理回路はまだ十分
に動作できる電圧である場合が多い。PROMs are generally more powerful than logic circuits that include normal ROMs.
The lowest limit of operating power supply voltage (hereinafter referred to as "minimum operating power supply voltage") is high. Therefore, in the above-mentioned conventional microcomputer with a built-in PROM, the minimum operating power supply voltage is set to a voltage as high as possible for PROM operation. however,
For example, even if the power supply voltage drops to the lowest operating power supply voltage of a PROM, the voltage is often still sufficient to operate logic circuits such as other ROMs.
本発明の目的は、全体の最低動作電源電圧を下げること
が可能なマイクロコンピュータを提供することにある。An object of the present invention is to provide a microcomputer that can lower the overall minimum operating power supply voltage.
本発明のマイクロコンピュータは、ＰＲＯＭとＲＯＭを
チップ上に内蔵したマイクロコンピュータにおいて、電
源電圧が所定電圧以上であるかないかを検出する電源電
圧検出回路と、前記電源電圧検出回路の出力信号に応答
して前記ＰＲＯＭの出力データ信号と前記ＲＯＭの出力
データ信号のどちらをデータバスに出力するかを切換え
る手段とを含むことを特徴とする。The microcomputer of the present invention has a PROM and a ROM built-in on a chip, and includes a power supply voltage detection circuit that detects whether a power supply voltage is higher than a predetermined voltage, and a power supply voltage detection circuit that responds to an output signal of the power supply voltage detection circuit. The device is characterized in that it includes means for switching which of the output data signal of the PROM and the output data signal of the ROM is output to the data bus.
次に、本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の一実施例を示すマイクロコンピュータ
のブロック図である。ＰＲＯＭｌは命令などのデータを
格納するＰＲＯＭ、ＲＯＭ２は低電圧で動作する時のデ
ータを格納するＲＯＭ、電源電圧検出回路６は電源電圧
が一定電圧以上であるかないかを検出する電源電圧検出
回路、切り換え回路５は電源電圧検出回路６の出力信号
である電源電圧検出信号７によって、ＰＲＯＭＩの動作
を禁止させる禁止信号を発生すると共にＲＯＭ２からの
出力だけをデータバス８に出させる切り換える切り換え
回路である。FIG. 1 is a block diagram of a microcomputer showing one embodiment of the present invention. PROM1 is a PROM that stores data such as commands, ROM2 is a ROM that stores data when operating at low voltage, power supply voltage detection circuit 6 is a power supply voltage detection circuit that detects whether the power supply voltage is above a certain voltage or not. The switching circuit 5 is a switching circuit that generates a prohibition signal for prohibiting the operation of PROMI based on the power supply voltage detection signal 7 which is an output signal of the power supply voltage detection circuit 6, and also causes only the output from the ROM 2 to be outputted to the data bus 8. .
以下、動作について説明する。電源電圧検出回路６の検
出電圧はＰＲＯＭｌの最低動作電源電圧より高い電圧に
設定しておく。電源電圧検出回路６は電源電圧が検出電
圧より高いとき、たとえばハイレベルを電源電圧検出信
号７に出力する。電源電圧検出信号７がハイレベルの時
、切り換え回路５は選択信号１０によりＰＲＯＭデータ
信号３又はＲＯＭデータ信号４のどちらかを選択してデ
ータバス８に出力する。すなわち、電源電圧が検出電圧
より高い時はＰＲＯＭＩに格納されたデータと、ＲＯＭ
２に格納されたデータどちらでも任意に選択信号により
データバス８に出力される。電源電圧が検出電圧より低
くなると、電源電圧検出回路６は電源電圧検出信号７に
ロウレベルを出力する。電源電圧検出信号７がロウレベ
ルの時、切り換え回路５はＰＲＯＭＩに対して動作を禁
止させる禁止信号９を発生させると共に、ＲＯＭデータ
信号４だけがデータバス８に出力されるようにする。す
なわち、電源電圧が検出電圧より低い時はＲＯＭ２に格
納されたデータだけがデータ信号８に出力される。The operation will be explained below. The detection voltage of the power supply voltage detection circuit 6 is set to a voltage higher than the lowest operating power supply voltage of PROMl. When the power supply voltage is higher than the detection voltage, the power supply voltage detection circuit 6 outputs, for example, a high level to the power supply voltage detection signal 7. When the power supply voltage detection signal 7 is at a high level, the switching circuit 5 selects either the PROM data signal 3 or the ROM data signal 4 according to the selection signal 10 and outputs it to the data bus 8. In other words, when the power supply voltage is higher than the detection voltage, the data stored in PROMI and the ROM
Either of the data stored in the data bus 2 is outputted to the data bus 8 by a selection signal. When the power supply voltage becomes lower than the detection voltage, the power supply voltage detection circuit 6 outputs a low level to the power supply voltage detection signal 7. When the power supply voltage detection signal 7 is at a low level, the switching circuit 5 generates an inhibition signal 9 for prohibiting the PROMI from operating, and only the ROM data signal 4 is output to the data bus 8. That is, when the power supply voltage is lower than the detection voltage, only the data stored in the ROM 2 is outputted as the data signal 8.
一般に、ＲＯＭの最低動作電源電圧の方が、ＰＲＯＭの
最低動作電源電圧より低い電圧であるので、本実施例の
マイクロコンピュータはＲＯＭの最低動作電源電圧まで
動作が保証される。Generally, the minimum operating power supply voltage of a ROM is lower than the minimum operating power supply voltage of a PROM, so the microcomputer of this embodiment is guaranteed to operate up to the minimum operating power supply voltage of the ROM.
以上説明した例では、電源電圧がＰＲＯＭの最低動作電
源電圧以上の通常電圧の時、選択信号によりＰＲＯＭと
ＲＯＭ２の信号を切り換えているが、本発明では通常電
圧の時はＰＲＯＭＩのＰＲＯＭデータ信号３をデータバ
ス８に出力し、ＰＲＯＭの最低動作電源電圧以下になっ
た時はＲＯＭ２のＲＯＭデータ信号４をデータバス８に
出力するように切り換え回路を設定しても、同様な効果
が得られる。In the example explained above, when the power supply voltage is a normal voltage higher than the lowest operating power supply voltage of PROM, the signals of PROM and ROM2 are switched by the selection signal, but in the present invention, when the power supply voltage is a normal voltage, the PROM data signal 3 of PROMI The same effect can be obtained by setting the switching circuit so that the ROM data signal 4 of the ROM 2 is outputted to the data bus 8 and the ROM data signal 4 of the ROM 2 is outputted to the data bus 8 when the voltage falls below the lowest operating power supply voltage of the PROM.
以上説明したように本発明は、電源電圧が検出電圧より
低い時はＲＯＭに格納されたデータだけをデータ信号に
出力することにより、ＰＲＯＭを内蔵したマイクロコン
ピュータ全体の最低動作電源電圧をＰＲＯＭの最低動作
電源電圧より低くできる効果がある。As explained above, the present invention outputs only the data stored in the ROM as a data signal when the power supply voltage is lower than the detection voltage. This has the effect of lowering the operating power supply voltage.
第１図は本発明の一実施例を示すマイクロコンピュータ
のブロック図である。
１・・・ＰＲＯＭ、２・・・ＲＯＭ、３・・・ＰＲＯＭ
データ信号、４・・・ＲＯＭデータ信号、５・・・切り
換え回路、６・・・電源電圧検出回路、７・・・電源電
圧検出信号、８・・・データ信号、９・・・禁止信号、
１０・・・選択信号。FIG. 1 is a block diagram of a microcomputer showing one embodiment of the present invention. 1...PROM, 2...ROM, 3...PROM
Data signal, 4... ROM data signal, 5... Switching circuit, 6... Power supply voltage detection circuit, 7... Power supply voltage detection signal, 8... Data signal, 9... Inhibition signal,
10...Selection signal.
Claims (1)
ピュータにおいて、電源電圧が所定電圧以上であるかな
いかを検出する電源電圧検出回路と、前記電源電圧検出
回路の出力信号に応答して前記ＰＲＯＭの出力データ信
号と前記ＲＯＭの出力データ信号のどちらをデータバス
に出力するかを切換える手段とを含むことを特徴とする
マイクロコンピュータ。In a microcomputer with a built-in PROM and a ROM on a chip, a power supply voltage detection circuit detects whether a power supply voltage is higher than a predetermined voltage or not, and an output data signal of the PROM in response to an output signal of the power supply voltage detection circuit. and means for switching which of the output data signals of the ROM is output to a data bus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1270890A JPH03130885A (en) | 1989-10-17 | 1989-10-17 | Microcomputer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1270890A JPH03130885A (en) | 1989-10-17 | 1989-10-17 | Microcomputer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03130885A true JPH03130885A (en) | 1991-06-04 |
Family
ID=17492397
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1270890A Pending JPH03130885A (en) | 1989-10-17 | 1989-10-17 | Microcomputer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03130885A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005536784A (en) * | 2002-01-19 | 2005-12-02 | ローベルト ボッシュ ゲゼルシャフト ミット ベシュレンクテル ハフツング | Method for monitoring completion of drive preparation of at least one memory element arranged in an electronic unit |
-
1989
- 1989-10-17 JP JP1270890A patent/JPH03130885A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005536784A (en) * | 2002-01-19 | 2005-12-02 | ローベルト ボッシュ ゲゼルシャフト ミット ベシュレンクテル ハフツング | Method for monitoring completion of drive preparation of at least one memory element arranged in an electronic unit |
| EP1470469B1 (en) * | 2002-01-19 | 2018-04-04 | Robert Bosch Gmbh | Method for monitoring the availability of at least one memory element that is assigned to an electronic unit |
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