JP3699942B2 - Memory management method and memory management device - Google Patents

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となる。
【０１５４】
図２７は、本発明の実施形態に係わるメモリ制御装置において、全ブロックに対して任意のデータライトを行った仮想セクタに対してオーバライトする時の例を示した図であり、同図（ａ）は、仮想セクタに対して一つ目のデータを書き込む前の状態を示す図であり、同図（ｂ）は、仮想セクタに対して一つ目のデータを書き込む際の物理セクタに対する処理および二つめのデータを書き込む前の状態を示す図であり、同図（ｃ）は、仮想セクタに対して二つめのデータを書き込む際の物理セクタに対する処理を示す図である。
【０１５５】
まず、図２７（ａ）において、既に全ブロックに対して任意のデータライトがなされた仮想セクタＧは物理セクタＸとセクタアドレス変換制御部２４により１対１で対応付けられる。ここで、仮想セクタＧの０番ブロックに任意のブロックデータ（ｐ１６１）をライトするものと仮定する。
【０１５６】
このとき、既に実際にライトすべき物理メモリ上の物理ブロック（ｐ１６２）はライト済であるので、図２７（ｂ）に示すように、セクタアドレス変換制御部２４により新しい物理セクタＹが用意され、ブロックデータ（ｐ１６１）が物理セクタＹ上の０番ブロックつまり物理ブロックアドレスが“０”である物理ブロック（ｐ１６３）にライトされ、セクタアドレス変換制御部２４により仮想セクタＧに対して物理セクタＹが新たに対応付けられる。このとき、仮想セクタＧと物理セクタＸとの対応付けは残ったままであるので、仮想セクタＧが物理セクタＸと物理セクタＹがともに対応付けられることになる。更に仮想セクタＧの０番ブロックに対応付けられる物理セクタＸの０番ブロック（ｐ１６２）と、同じく仮想セクタＧの０番ブロックに対応付けられる物理セクタＹの０番ブロック（ｐ１６３）のどちらのブロックに書き込まれたデータが有効すなわち最新ライト済のデータであるかを判別するためにブロック情報制御部２６でブロック情報が管理される。
【０１５７】
図３２と同様に、物理メモリへの一つのブロックのライト時間をｘ、リード時間をｙとし、一つのセクタがＭ個のブロックで構成されていると仮定すると、ブロックデータのライト処理終了までに要したメモリアクセス合計時間Ｔ２は、
【数２】

となる。
【０１５８】
なお、この場合、物理セクタＸの１番ブロックからＭ番ブロックまでのブロックデータ（ｐ１６７）は仮想セクタＧの１番ブロックからＭ番ブロックまでに対応付けられることになる。
【０１５９】
更に、図２７（ｂ）において、仮想セクタＧの１番ブロックに任意のデータ（ｐ１６４）をライトすると仮定する。
【０１６０】
この場合、実際にライトすべき物理セクタＹ上の１番ブロック（ｐ１６５）は空であるので、図２７（ｃ）で示すように、新規ブロックデータ（ｐ１６４）が物理セクタＹ上の１番ブロック（ｐ１６５）にライトされ、物理セクタＸ上の１番ブロック（ｐ１６６）と物理セクタＹ上の１番ブロック（ｐ１６５）のどちらのブロックに書き込まれたデータが有効であるかを判別するためにブロック情報制御部２６でブロック情報が管理される。
【０１６１】
なお、物理セクタＸの２番ブロックからＭ番ブロックまでのブロックデータ（ｐ１６８）は仮想セクタＧの２番ブロックからＭ番ブロックまでに対応付けられることになる。
【０１６２】
この場合、新規ブロックデータ（ｐ１６４）のライト処理終了までに要したメモリアクセス合計時間Ｔ３は、
【数３】

となる。
【０１６３】
図２８は、前記実施形態に係わるポインタ式ブロック情報テーブル２５の構成を示す図である。
【０１６４】
図２８に示すように、このポインタ式ブロック情報テーブル２５は、図６に示すフラグ式ブロック情報テーブル２５に代わって用いられるものであり、メモリ制御装置において、セクタ内のランダムブロックプログラムすなわち物理ブロック毎のブロック情報管理処理が禁止されている不揮発性メモリ１、および不揮発性メモリ１に対して自らランダムブロックプログラムが禁止されている場合に用いられるブロック情報テーブル２５である。
【０１６５】
このポインタ式ブロック情報テーブル２５では、ブロック情報制御部２６からの制御により、物理セクタアドレスをインデックス値としてこのインデックスに対応して未ライト、もしくはライト済の連続した物理ブロックの範囲の情報を、登録（ｐ１７１）、更新（ｐ１７２）および削除（ｐ１７３）することが可能であり、テーブル値すなわち物理ブロックの情報は各物理セクタに対するライト済の最終物理ブロックアドレス値もしくは、未ライトの先頭物理ブロックアドレス値である。
【０１６６】
例えば、ポインタ式のブロック情報テーブル２５に未ライトの先頭物理ブロックアドレス値を登録する場合で、ｐ１７４で示された物理セクタアドレスと物理ブロックアドレス値との関係は、物理セクタアドレスＢが物理ブロックアドレスβから最終ブロックまで未使用状態なことを示し、ｐ１７５で示された物理セクタアドレスと物理ブロックアドレス値との関係は、物理セクタアドレスＡが物理ブロックアドレスαからセクタの最終ブロックまで未使用状態なことを示している。
【０１６７】
また、ポインタ式のブロック情報テーブル２５にライト済の最終物理ブロックアドレスを登録する場合で、ｐ１７４で示された物理セクタアドレスと物理ブロックアドレス値との関係は、物理セクタアドレスＢが先頭ブロックから物理ブロックアドレスβまで使用状態にあることを示し、ｐ１７５で示された物理セクタアドレスと物理ブロックアドレス値との関係は、物理セクタアドレスＡが先頭ブロックから物理ブロックアドレスαまで使用状態にあることを示している。ただし、全ての物理ブロックが未使用である場合には、例えば“−１”などの、使用しない物理ブロックアドレス値を割り当てるものとする。
【０１６８】
図２９は、前記実施形態に係わるポインタ式ブロック情報テーブル２５における仮想セクタと物理セクタの各物理ブロックとの対応を示す図であり、同図（ａ）は、仮想セクタが一つの物理セクタの各物理ブロックと対応付けられた場合を示す図であり、同図（ｂ）は、仮想セクタが複数の物理セクタの各物理ブロックと対応付けられた場合を示す図である。
【０１６９】
この、仮想セクタと物理セクタの各物理ブロックとの対応とは、セクタアドレス変換テーブル２３において、仮想セクタＫ（ｐ１８１）が、それに対する登録順番の古い方から物理セクタアドレスＢ，Ａの順番で対応付けられると仮定した仮想セクタＫが、図２８のｐ１７４、ｐ１７５で示すように物理セクタアドレスＡ，Ｂと対応付けられる場合に、仮想セクタの各ブロックと、物理セクタの各物理ブロックとの対応を示している。
【０１７０】
なお、仮想セクタと物理セクタで共通となるブロックアドレス値は、未使用先頭ブロックオフセットアドレス値が登録されているものとし、“α”および“β”は最大物理ブロックアドレス“Ｍ”以外のブロックアドレス値であるものとする。
【０１７１】
図２９（ａ）に示すように、“α”＞“β”の場合には、ｐ１８２で示すように、仮想セクタＫの０ブロックからβ−１ブロックまでは物理セクタアドレスＢの０ブロックからβ−１ブロックが対応し、ｐ１８３で示すように、“β”ブロックから“α−1”ブロックまでは物理セクタアドレスＡの“β”ブロックから“α−1”ブロックが対応し、ｐ１８４で示すように、“α”から“Ｍ”ブロックまでは未使用ブロックで対応づけられる。
【０１７２】
また、図２９（ｂ）に示すように、“α”≦“β”の場合には、ｐ１８５で示すように、仮想セクタＫの“０”ブロックから“β−１”ブロックまでは物理セクタアドレスＢの“０”ブロックから“β−１”までが対応し、また、ｐ１８６で示すように、“β”から“Ｍ”ブロックまでは未使用ブロックで対応づけられる。
【０１７３】
つまり、図２９（ａ）に示すような場合には、仮想セクタＫと対応付けられる物理セクタアドレスＡのブロックアドレスの範囲が、同じく仮想セクタＫと対応付けられる物理セクタアドレスＢの範囲と重複しないために、仮想セクタＫの各仮想ブロックは物理セクタアドレスＡおよび物理セクタアドレスＢに属する各物理ブロックと対応付けられるが、図２９（ｂ）に示すような場合には、仮想セクタと対応付けられる物理セクタアドレスＡのブロックアドレスの範囲が、同じく仮想セクタと対応付けられる物理セクタアドレスＢの範囲に含まれてしまうために、仮想セクタＫの各仮想ブロックは物理セクタアドレスＡの各物理ブロックとは対応付けられずに、物理セクタアドレスＢに属する各物理ブロックのみと対応付けられることになる。
【０１７４】
図３０は、前記実施形態に係わるメモリ制御装置によるメモリイレーズ処理を示すフローチャートである。
【０１７５】
図３０に示すように、まず、システム制御部４よりコマンドバス１１を介してメモリ管理部２にメモリイレーズ命令（消去命令）が与えられるとともに、仮想メモリアドレスバス１２を介して仮想メモリアドレスがメモリ制御部２１に転送されると、仮想メモリアドレスがメモリ制御部２１により仮想セクタアドレスＡと仮想ブロックアドレスＢとに分けられる（ステップＤ１）。
【０１７６】
次に、セクタアドレス変換制御部２４によりセクタアドレス変換テーブル２３が読み出されて、このセクタアドレス変換テーブル２３と仮想セクタアドレスＡとが照合されて、該仮想セクタアドレスＡに対応付けられる一つまたは複数の物理セクタアドレスで構成される物理セクタアドレス群Ｃが存在するかどうかが判断される（ステップＤ２，Ｄ３）。
【０１７７】
ステップＤ３で「ＮＯ」と判断される、すなわち仮想セクタアドレスＡに対応付けられる物理セクタアドレス群Ｃが存在しない場合には、仮想セクタアドレスＡがどの物理セクタとも対応付けられてなく、つまりイレーズ対象が無いので終了処理がなされる。
【０１７８】
一方、ステップＤ３で「ＹＥＳ」と判断される、すなわち仮想セクタアドレスＡに対応付けられる物理セクタアドレス群Ｃが存在する場合には、ブロック情報制御部２６を介してブロック情報テーブル２５に登録される物理セクタアドレス群Ｃの全ブロック情報が消去すなわち“０”に更新処理される（ステップＤ４）。
【０１７９】
そして、セクタアドレス変換制御部２４を介してセクタアドレス変換テーブル２３から物理セクタアドレス群Ｃが削除される（ステップＤ５）。
【０１８０】
このメモリイレーズ処理により、仮想セクタアドレスＡは全ての物理セクタアドレスとの対応付けがなされなくなる。この時、仮想セクタアドレスＡをリードすると、対応する物理ブロックアドレス群が存在しないことになるので、消去処理が行われた適当な物理セクタアドレスの各ブロックデータが転送されることになる。
【０１８１】
つまり、このメモリイレーズ処理により、セクタアドレス変換テーブル２３とブロック情報テーブル２５からイレーズすべき仮想セクタアドレスに関する情報を削除するだけで、対応付けられた物理セクタアドレス群のメモリ上のデータ消去を行うことにより、イレーズ処理速度が向上する。
【０１８２】
図３１は、前記実施形態に係わるメモリ制御装置に備えられるセクタアドレス変換テーブル２３におけるメモリコピー処理およびメモリ移動処理を示す図である。
【０１８３】
このメモリコピー処理とは、コピー元の仮想セクタアドレスに対応付けられる物理セクタアドレス群を、このコピー元の仮想セクタアドレスとの対応付けを残したままで、コピー先の仮想セクタアドレスにも対応付ける処理のことであり、このメモリコピー処理によりコピー元の仮想セクタアドレスに対応付けられる全ての物理ブロック情報がコピー先の仮想セクタアドレスにも対応付けられることになる。
【０１８４】
また、メモリ移動処理とは、移動元の仮想セクタアドレスに対応付けられる物理セクタアドレス群を、移動元の仮想セクタアドレスとの対応付けを無くすとともにコピー先の仮想セクタアドレスに対応付ける処理のことであり、このメモリ移動処理により移動元の仮想セクタアドレスに対応付けられる全ての物理ブロック情報が移動先の仮想セクタアドレスに対応付けられることになる。
【０１８５】
なお、ここでは、転送元仮想セクタ、転送先仮想セクタおよびコピーか移動かの指定手段は問わないものとする。
【０１８６】
まず、メモリ制御装置によるメモリコピー処理について説明する。
【０１８７】
図３１に示すように、セクタアドレス変換テーブル２３において、転送元仮想セクタアドレスＡに物理セクタアドレス群（ｐ１９１）の“３”、“８”および“Ｎ”と対応付けられ、また、転送先仮想セクタアドレスＢが別の物理セクタアドレス群（ｐ１９２）と対応付けられている場合で、仮想セクタアドレスＡに対応付けられる全ブロックデータを仮想セクタアドレスＢにコピーする場合、つまり、システム制御部４よりコマンドバス１１を介してメモリ管理部２にメモリコピー命令が与えられるとともに、仮想メモリアドレスバス１２を介してコピー元およびコピー先の仮想メモリアドレスがメモリ制御部２１に転送されると、仮想セクタアドレスＢに対応付けられる、つまりｐ１９２に示す物理セクタアドレス群の全物理ブロックのブロック情報が削除され、ｐ１９１に示す物理セクタアドレス群の全データ、すなわち物理セクタアドレス“３”、“８”、“Ｎ”に属しており、かつ、仮想セクタアドレスＡと対応付けられる全ての物理ブロックアドレスおよびそのブロック情報が仮想セクタアドレスＢに対応付けられる。
【０１８８】
この時、仮想セクタアドレスＢは仮想セクタアドレスＡと同じ物理セクタと対応付けられることになるので、該物理セクタのブロックデータを変更する場合には、変更する物理セクタの全ブロックデータをコピーした新規物理セクタを用いて処理され、セクタアドレス変換テーブル２３における登録を置き換えることで処理されるものとする。
【０１８９】
次に、メモリ制御装置によるメモリ移動処理について説明する。
【０１９０】
同じく、セクタアドレス変換テーブル２３において、セクタアドレス変換テーブル２３において、転送元仮想セクタアドレスＣに物理セクタアドレス群（ｐ１９３）の“９”、“２”および“５”と対応付けられ、また、転送先仮想セクタアドレスＤが別の物理セクタアドレス群（ｐ１９４）と対応付けられている場合で、仮想セクタアドレスＢに対応付けられる全ブロックデータを仮想セクタアドレスＢに移動させる場合、つまり、システム制御部４よりコマンドバス１１を介してメモリ管理部２にメモリ移動命令が与えられるとともに、仮想メモリアドレスバス１２を介して移動元および移動先の仮想メモリアドレスがメモリ制御部２１に転送されると、仮想セクタアドレスＤに対応付けられる、つまりｐ１９４に示す物理セクタアドレス群の全物理ブロックのブロック情報およびが削除され、ｐ１９３に示す物理セクタアドレス群の全データ、すなわち物理セクタアドレス“９”、“２”、“５”に属しており、かつ、仮想セクタアドレスＣと対応付けられる全ての物理ブロックアドレスおよびそのブロック情報が仮想セクタアドレスＤに対応付けられるとともに、仮想セクタアドレスＣと物理セクタアドレス群（ｐ１９３）との対応付けがなくなる。
【０１９１】
つまり、これらのメモリコピー処理またはメモリ移動処理により、任意の仮想セクタから任意の仮想セクタに全ブロックデータをコピーする場合、または任意の仮想セクタから任意の仮想セクタに全ブロックデータを移動する場合であっても、不揮発性メモリ１上でのデータコピーまたはデータ移動が発生しないので、処理を高速化することができる。
【０１９２】
したがって、前記構成のメモリ制御装置によれば、セクタアドレス変換テーブル２３およびブロック情報テーブル２５により、一つの仮想セクタが複数の物理セクタと対応付けられた上で、メモリライト処理により、ライトすべき仮想セクタアドレスに対応付けられた物理セクタアドレス群中から適当な未ライトブロックが存在する物理セクタアドレスが検出され、また、メモリリード処理により、ライトすべき仮想セクタアドレスに対応付けられた物理セクタアドレス群中から適当なライト済ブロックが存在する物理セクタアドレスが検出され、また、メモリ結合処理により、セクタアドレス変換テーブル２３とブロック情報テーブル２５で複数の物理セクタアドレスとを対応付けられた仮想セクタアドレスが、一つの物理セクタアドレスと対応づけられ、また、メモリイレーズ処理により、イレーズすべき仮想セクタアドレスに対する物理セクタアドレス群が削除され、また、メモリコピー処理及びメモリ移動処理により、セクタアドレス変換テーブル２３上の仮想セクタアドレスと物理セクタアドレスの対応付けの情報が書き換えられるので、メモリの読み書きに係る処理時間を短縮し、また、メモリ資源を効率よく使うことが可能になる。
【０１９３】
【発明の効果】
以上のように、本発明に係わるメモリ管理方式によれば、各々が物理ブロックを書き込み単位として複数有してなる物理セクタを消去単位として複数有してなる物理メモリおよび当該物理メモリの物理セクタと対応付けた仮想セクタを複数有してなる仮想メモリを用いてデータの読み書きを管理するメモリ管理方式であって、仮想セクタのアドレスと単一または複数の物理セクタのアドレスとを当該仮想セクタのアドレス毎に対応付けるセクタアドレス管理手段と、このセクタアドレス管理手段により仮想セクタのアドレスと対応付けた複数の物理セクタの各アドレスの対応付けのタイミングの順序を管理する順序管理手段と、物理セクタに属する物理ブロックの使用状態を示すブロック情報を管理するブロック情報管理手段と、データ書き込み対象の仮想メモリアドレスで示される物理ブロックのアドレスを計算する第１の計算手段と、書き込み対象の仮想メモリアドレスで示される仮想セクタのアドレスを計算する第２の計算手段と、ブロック情報管理手段により管理されるブロック情報および順序管理手段により管理される順序に基づいて、第２の計算手段により計算した仮想セクタのアドレスに対してセクタアドレス管理手段により対応付けられる物理セクタの各アドレスおよび第１の計算手段により計算したアドレスと対応する使用状態にある物理ブロックのうち最も遅い順序で計算した仮想セクタのアドレスに対してセクタアドレス管理手段により対応付けられた物理セクタのアドレスより後の順序で計算した仮想セクタのアドレスに対してセクタアドレス管理手段により対応付けられた物理セクタのアドレスを書き込み対象の物理セクタのアドレスとして検出するセクタアドレス検出手段とを有し、セクタアドレス管理手段は、セクタアドレス検出手段によりアドレスが検出されなかった場合に属する全ての物理ブロックが未使用状態にある物理セクタのアドレスを計算した仮想セクタのアドレスと新たに対応付け、順序管理手段は、この新たに対応付けられた物理セクタのアドレスが計算した仮想セクタのアドレスとセクタアドレス管理手段により最も遅い順序で対応付けられたとして管理し、新たに対応付けられた物理セクタのアドレスを書き込み対象の物理セクタのアドレスとして指定するセクタアドレス指定手段を有し、ブロック情報管理手段は、セクタアドレス指定手段により指定されたアドレスおよび第１の計算手段により計算した物理ブロックのアドレスで特定される物理ブロックのブロック情報を使用状態を示す情報に書き換えることになる。
【０１９８】
したがって、本発明は不揮発性メモリの読み書きに係る処理時間を短縮し、また、メモリ資源を効率よく使うことが可能になる。
【図面の簡単な説明】
【図１】本発明の実施形態に係わるメモリ制御装置の構成を示す図。
【図２】前記実施形態に係わるメモリ制御装置に備えられるメモリ管理部の構成を示す図。
【図３】前記実施形態に係わるメモリ制御装置に備えられるセクタアドレス変換テーブルの構成を示す図。
【図４】前記実施形態に係わるメモリ制御装置に備えられるセクタアドレス変換テーブルによる仮想メモリと物理メモリの対応付けの例を示す図。
【図５】前記実施形態に係わる仮想セクタと物理セクタとの対応付けの例を示す図。
【図６】前記実施形態に係わるメモリ制御装置に備えられるブロック情報テーブルの構成を示す図。
【図７】前記実施形態に係わるメモリ制御装置によるメモリライト処理（その１）を示すフローチャート。
【図８】前記実施形態に係わるメモリ制御装置によるメモリライト処理（その２）を示すフローチャート。
【図９】前記実施形態に係わるメモリライト処理において未ライトブロックが存在する物理セクタアドレスＤが検出される例を示す図。
【図１０】 前記実施形態に係わるメモリライト処理において未ライトブロックが存在する物理セクタアドレスＤを検出できない例を示す図。
【図１１】前記実施形態に係わるブロック情報テーブル内のブロック情報の更新処理を示す図。
【図１２】前記実施形態に係わるブロック情報テーブルに対する新規物理セクタアドレスの登録処理と、この登録処理に伴うブロック情報の更新処理を示す図。
【図１３】前記実施形態に係わるメモリ制御装置によるメモリリード処理（その１）を示すフローチャート。
【図１４】前記実施形態に係わるメモリ制御装置によるメモリリード処理（その２）を示すフローチャート。
【図１５】前記実施形態に係わるメモリリード処理においてライト済ブロックが存在する物理セクタアドレスＤが検出される例を示す図。
【図１６】 前記実施形態に係わるメモリリード処理においてライト済ブロックが存在する物理セクタアドレスＤが検出されない例を示す図。
【図１７】前記実施形態に係わるブロック情報テーブルに対する新規物理セクタアドレスの登録処理を示す図。
【図１８】前記実施形態に係わるメモリ制御装置によるメモリ結合処理（その１）を示すフローチャート。
【図１９】前記実施形態に係わるメモリ制御装置によるメモリ結合処理（その２）を示すフローチャート。
【図２０】前記実施形態に係わるメモリ制御装置によるメモリ結合処理（その３）を示すフローチャート。
【図２１】前記実施形態に係わるメモリ結合処理におけるブロック情報テーブルでの登録処理および削除処理を示す図。
【図２２】前記実施形態に係わるメモリ結合処理においてライト済ブロックが存在する物理セクタアドレスＤを検出する例を示す図。
【図２３】前記実施形態に係わるメモリ結合処理においてライト済ブロックが存在する物理セクタアドレスＤが検出されない例を示す図。
【図２４】前記実施形態に係わるメモリ結合処理において、最新ライト済ブロックの検出例を示す図。
【図２５】 前記実施形態に係わるメモリ結合処理においてセクタアドレス変換テーブルでの登録処理および削除処理を示す図。
【図２６】 前記実施形態に係わるメモリ結合処理において、結合対象となる物理ブロックアドレスを任意に選択する場合の処理を示すフローチャート。
【図２７】 本発明の実施形態に係わるメモリ制御装置において、全ブロックに対して任意のデータライトを行った仮想セクタに対してオーバライトする時の例を示した図であり、同図（ａ）は、仮想セクタに対して一つ目のデータを書き込む前の状態を示す図であり、同図（ｂ）は、仮想セクタに対して一つ目のデータを書き込む際の物理セクタに対する処理および二つめのデータを書き込む前の状態を示す図であり、同図（ｃ）は、仮想セクタに対して二つめのデータを書き込む際の物理セクタに対する処理を示す図。
【図２８】前記実施形態に係わるポインタ式ブロック情報テーブルの構成を示す図。
【図２９】前記実施形態に係わるポインタ式のブロック情報テーブルにおける仮想セクタと物理セクタの各物理ブロックとの対応を示す図であり、同図（ａ）は、仮想セクタが一つの物理セクタの各物理ブロックと対応付けられた場合を示す図であり、同図（ｂ）は、仮想セクタが複数の物理セクタの各物理ブロックと対応付けられた場合を示す図。
【図３０】前記実施形態に係わるメモリ制御装置によるメモリイレーズ処理を示すフローチャート。
【図３１】前記実施形態に係わるメモリ制御装置に備えられるセクタアドレス変換テーブルにおけるメモリコピー処理およびメモリ移動処理を示す図。
【図３２】 従来のメモリ制御装置において、全ブロックに対して任意のデータライトを行った仮想セクタに対してオーバライトする時の例を示した図であり、同図（ａ）は、仮想セクタに対してデータを書き込む前の状態を示す図であり、同図（ｂ）は、仮想セクタに対してデータを書き込む際の物理セクタに対する処理を示す図。
【符号の説明】
１・・・不揮発性メモリ
２・・・メモリ管理部
３・・・メモリインタフェース
４・・・システム制御部
１１・・・コマンドバス
１２・・・仮想メモリアドレスバス
１３・・・データバス
１４・・・メモリアクセスコマンドバス
１５・・・物理メモリアドレスバス
１６・・・メモリデータバス
１７・・・メモリバス
２１・・・メモリ制御部
２２・・・データバッファ
２３・・・セクタアドレス変換テーブル
２４・・・セクタアドレス変換制御部
２５・・・ブロック情報テーブル
２６・・・ブロック情報制御部[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a memory management method in a non-volatile memory in which an erase unit is composed of a plurality of write unitsAnd memory management deviceAbout.
[0002]
[Prior art]
  In the prior art, the correspondence of the sector (physical memory) of the memory (physical memory) on the nonvolatile memory to the erasing unit (sector) of the memory (virtual memory) viewed from the system is one for each virtual sector.PhysicsIt was a method of associating sectors.
[0003]
[Problems to be solved by the invention]
  However, when an overwrite occurs on a write unit area (block) on which a data write has already been performed on a physical sector associated with a virtual memory, a new physical sector to which no data has been written is assigned.PreparationThen, the block data to be updated and the block data other than the block to be overwritten on the sector to which the block to be overwritten belong are written on the new physical sector, and the virtual sector and the existing physical sector are written. Since it is necessary to erase the sector association and associate it with a new physical sector, the processing time of data write becomes longer as block data other than the overwrite block needs to be written to the new physical sector. There was a problem that the memory capacity to be used increased.
[0004]
  The present invention has been made in order to solve the above-described problem, and is a memory management method capable of shortening a processing time related to reading and writing of a memory and efficiently using memory resources.And memory management deviceThe purpose is to provide.
[0005]
  That is, the present inventionInEach memory management system involved isMultiple physical blocks as write unitsHaveMultiple physical sectors as erasure unitsPhysical memoryandCorresponds to the physical sector of the physical memoryMultiple virtual sectorsA memory management method for managing reading and writing of data using a virtual memory having a virtual sector address and a single or a plurality of physical sector addresses.For each virtual sector addressA sector address management means to be associated;Order management means for managing the order of timing of correspondence of each address of a plurality of physical sectors associated with the address of the virtual sector by this sector address management means;Block information management means for managing block information indicating a use state of a physical block belonging to a physical sector;First calculation means for calculating the address of the physical block indicated by the virtual memory address to be written with data, second calculation means for calculating the address of the virtual sector indicated by the virtual memory address to be written, and block information management Based on the block information managed by the means and the order managed by the order management means, each address of the physical sector associated with the virtual sector address calculated by the second calculation means by the sector address management means and the first The virtual sector address calculated in the slowest order among the physical blocks in use corresponding to the address calculated by one calculating means is in an order after the physical sector address associated by the sector address managing means. Sector address for the calculated virtual sector address As the address of the physical sector write target address of the associated physical sector by physical meansSector address detecting means for detectingThe sector address management means newly associates with the address of the virtual sector that has calculated the address of the physical sector in which all the physical blocks belonging to the case where the address is not detected by the sector address detection means. The order management means manages the address of the newly associated physical sector as being associated with the calculated virtual sector address in the latest order by the sector address management means. Sector address designating means for designating the address of the physical sector as the address of the physical sector to be written, and the block information management means is for the address designated by the sector address designating means and the physical block calculated by the first computing means. The block information of the physical block specified by the address is used Wherein the rewriting of information indicating.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a diagram showing a configuration of a memory control device according to an embodiment of the present invention.
[0017]
As shown in FIG. 1, the memory control device includes a nonvolatile memory 1, a memory management unit 2, a memory interface 3, and a system control unit 4.
[0018]
The memory management unit 2 is connected to the system control unit 4 that controls the system via a command bus 11, a virtual memory address bus 12, and a data bus 13 that transfer a signal indicating a command (instruction) to the memory management unit 2. The memory interface 3 transfers a signal indicating a command for the memory interface 3 to the memory management unit 2, the memory access command bus 14, the physical memory address bus 15, and between the memory management unit 2 and the memory interface 3. A memory data bus 16 for transferring data is connected, and the nonvolatile memory 1 is connected to the memory interface 3 via a memory bus 17.
[0019]
The memory bus 17 transfers a signal indicating an access command (processing instruction) for read / write access to the nonvolatile memory 1.
[0020]
The virtual memory address bus 12 transfers a signal indicating a virtual memory address on the virtual memory from the system control unit 4 to the memory management unit 2.
[0021]
The physical memory address bus 15 transfers a signal indicating a physical memory address on the nonvolatile memory 1 from the memory management unit 2 to the memory interface 3.
[0022]
The data bus 13 transfers data to be read from and written to the nonvolatile memory 1 between the system control unit 4 and the memory interface 3 via the memory management unit 2.
[0023]
The memory management unit 2 transfers the access command and the physical memory address to the memory interface 3 according to the command and virtual memory address transferred from the system control unit 4, and also writes data to be written in the nonvolatile memory 1 to the memory interface 3. The data transferred and read from the nonvolatile memory 1 is transferred to the system control unit 4.
[0024]
The memory interface 3 performs access processing to the nonvolatile memory 1 via the memory bus 17.
[0025]
FIG. 2 is a diagram illustrating a configuration of the memory management unit 2 provided in the memory control device according to the embodiment.
[0026]
As shown in FIG. 2, the memory management unit 2 includes a memory control unit 21, a data buffer 22, a sector address conversion table 23, a sector address conversion control unit 24, a block information table 25, and a block information control unit 26.
[0027]
The data buffer 22 is connected to the memory control unit 21, the command bus 11 and the virtual memory address bus 12 are connected to the memory control unit 21 from the system control unit 4, and the memory interface 3 is connected to the memory control unit 21. A physical memory address bus 15 and an access command bus 11 are connected to the data buffer 22. A data bus 13 is connected to the data buffer 22 from the system control unit 4. A memory data bus is connected from the data buffer 22 to the memory interface 3. 16 is connected.
[0028]
Further, the sector address conversion table 23 is connected to the memory control unit 21 via the sector address conversion control unit 24, and the block information table 25 is connected via the block information control unit 26.
[0029]
The sector address conversion table 23 is a memory that stores data indicating the correspondence between the sector unit address (virtual sector address) of the virtual memory and the sector unit address (physical sector address) of the physical memory.
[0030]
The block information table 25 is data indicating the use status of a plurality of physical blocks set in the physical sector address, that is, data indicating whether the block is used or not used (block Information).
[0031]
The sector address conversion control unit 24 registers, deletes, and reads one or a plurality of physical sector addresses associated with each virtual sector address by using all virtual sector addresses belonging to the virtual memory in the sector address conversion table 23 as index values. In addition, a physical sector address that is not registered in the sector address conversion table 23 is searched.
[0032]
The block information control unit 26 registers, deletes, updates, and reads block information with respect to each physical block that belongs to the physical sector address by using all the physical sector addresses that belong to the physical memory in the block information table 25 as index values.
[0033]
The memory control unit 21 controls the memory control unit 21 and the block information control unit 26 in accordance with a command from the system control unit 4, and changes to an appropriate physical memory address based on the virtual memory address. The access command is transferred to the non-volatile memory 1 via the data buffer 22 and the transfer control of data to be read / written is performed.
[0034]
The data buffer 22 adjusts the data transfer rate between the system control unit 4 and the nonvolatile memory 1.
[0035]
FIG. 3 is a diagram showing a configuration of the sector address conversion table 23 provided in the memory control device according to the embodiment.
[0036]
As shown in FIG. 3, the sector address conversion table 23 is table data for managing the correspondence between virtual sector addresses and physical sector addresses, and a virtual sector address index in which all virtual sector addresses in the virtual memory are registered. One virtual sector address in (p1) is associated with each physical sector address in a physical sector address group made up of one physical sector address or a plurality of physical sector addresses.
[0037]
That is, in the case of the sector address conversion table 23 shown in FIG. 3, a virtual sector address “0” is a physical sector address group composed of physical sector addresses “3”, “8”, “N”, and “α”. (P2) indicates that the physical sector addresses in the physical sector address group are arranged in accordance with the registration order, that is, the order associated with the virtual sector address.
[0038]
That is, the leftmost physical sector address “3” of the physical sector address group (p2) indicates the physical sector address first associated with the virtual sector address “0”, and the rightmost physical sector address “α” The physical sector address associated with the virtual sector address “0” is shown. In this case, the size of the physical sector address is not related to the registration order.
[0039]
The virtual sector address and the physical sector address are newly associated with the virtual sector address when no physical sector address is associated with the virtual sector address “1” shown in FIG. In the case where the physical sector address is already associated with the virtual sector address like the virtual sector address “2”, the new physical sector address “18” is added after the physical sector “9”. If registration is desired, the physical sector address registration order is changed in the physical sector address group as shown in p3, or a new physical sector address in the physical sector address group is registered as the registration order immediately after the last physical sector address. It is made by adding as.
[0040]
Further, in order to eliminate the association between the virtual sector address and the physical sector address, the physical sector address is deleted from the physical sector address group as shown in p4.
[0041]
FIG. 4 is a diagram showing an example of correspondence between virtual memory and physical memory by the sector address conversion table 23 provided in the memory control device according to the embodiment.
[0042]
As shown in FIG. 4, in the virtual memory sector address map indicating each virtual sector address of the virtual memory and the physical memory sector address map indicating each physical sector address of the physical memory, one for each virtual sector. Alternatively, a plurality of physical sectors are associated.
[0043]
In the virtual memory sector address map shown in FIG. 4, the 0 sector, 1 sector, 2 sectors,..., L-1 sector and L sector are virtual sector addresses “0”, “1”, “2”, .., Indicates an area indicating “L-1” and “L”, and the 0 sector, 1 sector, 2 sectors,..., N−1 sector and N sector of the physical memory sector address map are physical sector addresses “ 0 ”,...“ N−1 ”and“ N ”.
[0044]
Also, each physical sector distinguished by one physical sector, that is, a physical sector address is composed of a plurality of physical blocks as indicated by p11, and each physical block is distinguished by a physical block address.
[0045]
That is, the 0 block, 1 block,..., M−1 block and M block of each physical block shown in FIG. 4 have physical block addresses “0”, “1”,. This is an area indicating -1 "and" M ".
[0046]
FIG. 5 is a diagram showing an example of association between virtual sectors and physical sectors according to the embodiment.
[0047]
As shown in FIG. 5, the virtual sector (p21) includes a plurality of virtual blocks (p22), and each virtual block is distinguished by a virtual block address.
[0048]
Each virtual block is associated with each physical block in the physical block group indicated by p23.
[0049]
The 0 block, 1 block,..., M−1 block and M block of each virtual block are areas indicating virtual block addresses “0”,..., “M−1” and “M” in the virtual sector. is there.
[0050]
Then, the 0 block that is a virtual block in the virtual sector is associated with the physical sector (the 0th block of the 8th sector) to which the 0 block having the same physical block address value as the virtual block address value belongs.
[0051]
That is, by associating each virtual block with a physical block having the same address value, a virtual sector is associated with one or a plurality of physical sectors to which the physical block belongs.
[0052]
FIG. 6 is a diagram showing a configuration of the block information table 25 provided in the memory control device according to the embodiment.
[0053]
As shown in FIG. 6, this block information table 25 is a table for managing physical block information related to all physical blocks belonging to each physical sector address registered in the sector address conversion table 23.
[0054]
  thisBlock information table 25Is a physical sector address index (p31) in which all physical sector addresses in the physical memory are registered, and a physical block address index (p32) in which all physical block addresses belonging to each physical sector address of the physical sector address index are registered. ), And physical sector address index The physical block information storage area that stores the physical block information of each physical block, and the block information is stored with the physical sector address group as the first index and the physical block address group as the second index An area is referenced.
[0055]
For example, the block storage area indicated by p33 is a block information storage area of a physical block whose physical block address is “M” in a physical sector whose physical sector address is “0”.
[0056]
The physical block information stored in this block information storage area is information indicating whether or not data has been written to the physical memory address derived from the physical sector address and physical block address of the reference source. ) A flag of “1” is stored in a completed state, and a flag of “0” is stored in a state where data has not been written, that is, data has not been written.
[0057]
Further, as indicated by p34, the block information of a specific physical block corresponding to an arbitrary physical sector address can be updated to “0” or “1”. Further, block information of all physical blocks corresponding to the area indicated by p35, that is, any physical sector address can be registered, and all areas corresponding to the area indicated by p36, that is, any physical sector address can be registered. Block information of a physical block can be deleted.
[0058]
That is, one virtual sector can be identified by the block information table 25 that can know the use state of each block of the physical sector address associated with the sector address conversion table 23 that can associate the virtual sector address with a plurality of physical sector addresses. Since there is no need to associate one virtual sector with only one physical sector because it is associated with a plurality of physical sectors, high-speed memory writing can be performed with little occurrence of data movement on the memory during overwriting.
[0059]
In addition, since the usage state is indicated by the flags “0” and “1” for each arbitrary block, management can be performed in units of blocks suitable for the system, so the memory capacity of the block information table 25 can be reduced. Can be reduced.
[0060]
Next, processing of the memory control device having the above configuration will be described.
[0061]
First, a memory write (write) process by the memory control device will be described.
[0062]
FIG. 7 is a flowchart showing memory write processing (part 1) by the memory control apparatus according to the embodiment.
[0063]
FIG. 8 is a flowchart showing memory write processing (part 2) by the memory control apparatus according to the embodiment.
[0064]
As shown in FIGS. 7 and 8, first, a write command is given from the system control unit 4 to the memory management unit 2 of the memory control unit 21 via the command bus 11 and the virtual memory is sent via the virtual memory address bus 12. When the address is transferred to the memory control unit 21, the virtual memory address is divided into a virtual sector address A and a virtual block address (virtual block offset address) B by the memory control unit 21 (step A1).
[0065]
Based on the virtual block address B, a physical block address having the same address value is searched on the physical block address index on the block information table and handled as the physical block address B.
[0066]
Next, the sector address conversion control unit 24 reads out the sector address conversion table 23, compares the sector address conversion table 23 with the virtual sector address A, and A physical sector address group C composed of a plurality of physical sector addresses is searched to determine whether or not this physical sector address group C exists (steps A2 and A3).
[0067]
If “YES” is determined in step A3, that is, if the physical sector address group C is associated with the virtual sector address A, the block information table 25 is read by the block information control unit 26, and this block information table 25, on the basis of the physical block address (physical block offset address) of each physical sector address and virtual block address B belonging to the physical sector address group C, an unwritten block, that is, block information in each physical block is “ It is determined whether or not a physical block of 0 ″ is included. If an unwritten block is included, the physical sector address to which one of the physical blocks belongs is detected as the physical sector address D, and the sector address conversion table 23 is detected. Your search on That (step A4, A5).
[0068]
FIG. 9 is a diagram illustrating an example in which a physical sector address D in which an unwritten block exists is detected in the memory write processing according to the embodiment.
[0069]
That is, as shown in FIG. 9, in the sector address conversion table 23, the physical sector addresses belonging to the physical sector address group C associated with the virtual sector address A are registered from the oldest registration order as shown in p41. In the case of “3”, “8” and “N” and the virtual block address B is “M−1”, the physical block to be searched becomes a search string surrounded by p42, and the search is performed. The order in which the physical sector addresses belonging to the physical sector address group C are registered from the newest to the oldest as shown in p43, that is, the physical sector address is “N” and the physical block address is “M”. -1 "is searched from the physical block (p44), and then the physical sector address is" 8 "and the physical block address is" M-1 ". Associated with the physical block (p45) is searched, and finally the physical sector address of "3," a physical physical block address is associated with "M-1" block (p46) is searched.
[0070]
Then, according to the registration order of the physical sector address, an unwritten block corresponding to the physical sector address in the registration order immediately before the physical sector address corresponding to the written block whose registration order is the latest in the search sequence, that is, the physical sector A block (p45) having an address “8” and a physical block address “M−1” is detected as an unwritten block, and the detected physical sector address D is “8”.
[0071]
The unwritten block search method may be a method of detecting the physical sector address corresponding to the first unwritten block detected in the search order as the physical sector address D. In this case, the block information shown in FIG. The physical sector address D detected from the table 25 is “N”.
[0072]
  FIG. 10 relates to the embodiment.Memory lightIt is a figure which shows the example which cannot detect the physical sector address D in which the unwritten block exists in a process.
[0073]
As shown in FIG. 10, each element sector address of the memory sector address group C is composed of “3”, “8” and “N” from the oldest registration, and the virtual block address B is “M”. The search string is a search string indicated by p51, and the search is performed in order from the block (p52) corresponding to the new physical sector address registered. In this case, all the searched blocks have been written, that is, the block information of all the searched physical blocks is all “1”, and the written block with the latest registration order is searched in the search string. Since an unwritten block is not detected until then, there is no detected physical sector address D.
[0074]
FIG. 11 is a diagram showing a block information update process in the block information table 25 according to the embodiment.
[0075]
That is, as shown in FIG. 11, when the detected physical sector address D is “8” and the virtual block address B is “M−1”, the block information in the block information table 25 to be updated is Since this is a block indicated by p61, this block information is rewritten from “0” to “1”, that is, an unwritten block is updated to a written block.
[0076]
On the other hand, if “NO” is determined in step A3, that is, if the physical sector address group C is not associated with the virtual sector address A, or “NO” is determined in step A4, that is, in an unwritten block. When a certain physical sector address D is not detected, an unwritten block to be used for writing is not associated with the virtual sector address A, so a new unwritten block into which data can be written is obtained. That is, a physical sector address that is not registered in the sector address conversion table 23 is newly registered in the block information table 25, and this physical sector address is set as the physical sector address D (step A6).
[0077]
Here, since each block of the physical sector address D may have been written, all the block information of the block belonging to the physical sector address D is erased with respect to the physical sector address D through the memory interface 3, ie, “0”. (Step A7).
[0078]
Then, the physical sector address D is the physical registration order at the end of the physical memory sector address group C as a new physical sector address corresponding to the virtual sector address A in the sector address conversion table 23 via the sector address conversion control unit 24. Registered in the registration order immediately after the sector address (step A8), and each physical block belonging to this new physical sector address is registered in the block information table 25 through the block information control unit 26 as a physical block which is an unwritten block. (Step A9).
[0079]
FIG. 12 is a diagram showing a new physical sector address registration process for the block information table 25 according to the embodiment and a block information update process associated with the registration process.
[0080]
  That is, as shown in FIG.6If the new physical sector address D added in step S is “α”, step A7As a result, the block information belonging to the physical sector address D (= “α”) is erased, and all the block information of the physical sector address D (= α) becomes an unwritten block as shown in p71. Each physical block belonging to the new physical sector address is registered in the information table 25 (p72).
[0081]
If the virtual block address B to be searched for an unwritten block is “M”, the information of the physical block (p73) having the physical sector address “α” and the physical block address “M” is stored. The unwritten block is updated to the written block, that is, rewritten from “0” to “1”.
[0082]
  Step A5If the physical sector address D is detected, or if a physical block belonging to the new physical sector address is registered in the block information table 25 in step A8, the physical sector address D and physical A physical memory address E is calculated from the block address B, and a memory write, that is, a data write to the nonvolatile memory 1 is performed via the memory interface 3.InstructionsThe memory access command to be transferred is transferred, and block data from the system control unit 4 in the data buffer 22 is transferred to the physical memory address E (steps A10 and A11).
[0083]
  Then, the block information of the physical block corresponding to the physical sector address D and the physical block address B registered in the block information table 25 via the block information control unit 26 indicates that writing has been completed.1(Step A12).
[0084]
  In other words, the physical sector address in which an appropriate unwritten block exists is detected from the physical sector address group associated with the virtual sector address to be written by the memory write process, so it is necessary to newly allocate a physical sector. This makes it possible to effectively use non-memory resources.
In addition, the sector address conversion table 23 manages the order in which the physical sector addresses are associated with the virtual sector addresses, and the physical block address B and the physical sector address group C are used for data write processing. The physical block specified by the address of the physical sector associated with the virtual sector address A in the latest order among the blocks is set as the physical block to be written.
Further, when a new physical sector address is associated with a virtual sector address in the data write process, it is managed that the order in which the physical sector address is associated with the virtual sector address is the latest. Therefore, in the data write process, the order of association with the virtual sector address of the physical block that has been newly written in the physical block group corresponding to the same physical block address managed by the block information table 25 is older. It becomes unnecessary to update the block information of the physical block indicated by the address associated with the virtual sector address in order.
[0085]
Next, a memory read (read) process by the memory control device will be described.
[0086]
FIG. 13 is a flowchart showing memory read processing (part 1) by the memory control apparatus according to the embodiment.
[0087]
FIG. 14 is a flowchart showing a memory read process (part 2) by the memory control apparatus according to the embodiment.
[0088]
  As shown in FIGS. 13 and 14, first, the system control unit 4 via the command bus 11Memory management unit 2When a memory read command (read command) is given to the virtual memory address and the virtual memory address is transferred to the memory control unit 21 via the virtual memory address bus 12, the virtual memory address is transferred to the virtual sector address A by the memory control unit 21. It is divided into block address B (step B1).
[0089]
Next, the sector address conversion control unit 24 reads out the sector address conversion table 23, compares the sector address conversion table 23 with the virtual sector address A, and It is determined whether or not there is a physical sector address group C composed of a plurality of physical sector addresses (steps B2 and B3).
[0090]
If “YES” is determined in step B 3, that is, if the physical sector address group C is associated with the virtual sector address A, the block information table 25 is read by the block information control unit 26, and this block information table 25, based on each physical sector address belonging to the physical sector address group C and the physical block address B having the same address value as the virtual block address B, a written block, that is, a block whose block information is “1” in each block Is included, and if a written block is included, the physical sector address to which one physical block belongs is detected as the physical sector address D, and if the written block is not included , One of the physical blocks belongs in the search column Physical sector address is detected as a physical sector address D (step B4).
[0091]
FIG. 15 is a diagram illustrating an example in which a physical sector address D in which a written block exists is detected in the memory read processing according to the embodiment.
[0092]
That is, as shown in FIG. 15, the physical sector addresses belonging to the physical sector address group C associated with the virtual sector address A are “3”, “8”, and “N” from the oldest registration order. If the virtual block address B is “M−1”, the physical block to be searched is a search string indicated by p81, and the search order is the physical sector addresses belonging to the physical sector address group C. From the newest to the oldest registration order, that is, from the physical block (p82) associated with the physical sector address “N” and the physical block address “M−1”, and then the physical sector address is “8”. ", The physical block (p83) associated with the physical block address" M-1 "is searched, and finally the physical sector address" 3 " Physical associated with click address "M-1" block (p84) is to be searched.
[0093]
Then, according to the registration order of the physical sector address, the first written block detected in the search string, that is, the block (p83) having the physical sector address “8” and the physical block address “M−1” is written. The detected physical sector address D is “8”.
[0094]
  FIG. 16 shows that the physical sector address D in which a written block exists is detected in the memory read processing according to the embodiment.AbsentIt is a figure which shows an example.
[0095]
As shown in FIG. 16, when each element sector address of the memory sector address group C is composed of “3”, “8” and “N” from the oldest registration, and the virtual block address B is “1”. The search string is a search string indicated by p91, and the physical blocks indicated by p92, p93, and p94 are sequentially searched from the block corresponding to the registered new physical sector address. In this case, since the searched block is an unwritten block, that is, a written block whose block information is “1” is not detected, the physical sector address to which the first unwritten block (p92) detected in the search string belongs is assigned. That is, the latest physical sector address to which the block of the search string belongs, that is, the physical sector address “N” is detected as the physical sector address D.
[0096]
The physical sector address D detected here is not limited to the latest physical sector address to which the physical block of the search string belongs, but belongs to any physical block belonging to the search string (p91) by changing the detection condition. The physical sector address may be detected as the physical sector address D.
[0097]
On the other hand, if “NO” is determined in step B3, that is, if the physical sector address group C is not associated with the virtual sector address A, the physical block is not associated with the virtual sector address A. Therefore, in order to newly obtain a physical block from which data can be read, a physical sector address that is not registered in the sector address conversion table 23 is additionally registered in the block information table 25 from the sector address conversion control unit 24, and this physical sector The address is set as the physical sector address D (step B5).
[0098]
Since there is a possibility that each block of the set physical sector address D has been written, an erase process is performed on the physical sector address D through the memory interface 3 (step B6).
[0099]
Then, the physical sector address D is the physical registration order at the end of the physical memory sector address group C as a new physical sector address corresponding to the virtual sector address A in the sector address conversion table 23 via the sector address conversion control unit 24. Registered in the registration order immediately after the sector address (step B7), and each physical block belonging to this new physical sector address is registered in the block information table 25 via the block information control unit 26 as a physical block that is an unwritten block. (Step B8).
[0100]
FIG. 17 is a diagram showing a new physical sector address registration process for the block information table 25 according to the embodiment.
[0101]
That is, as shown in FIG. 17, when the value of the new physical sector address D added in step B5 is “γ”, block information belonging to the physical sector address D (= “γ”) is obtained in step B6. As shown in p101, all block information of the physical sector address D (= “γ”) becomes an unwritten block, and belongs to the new physical sector address in the existing block information table 25 (p102) by step B8. Each physical block is registered.
[0102]
If the physical sector address D is detected in step B4, or if a physical block belonging to the new physical sector address is registered in the block information table 25 in step B8, the physical sector address D and physical block address B are The memory address E is calculated, and a memory access command for instructing data read is transferred to the nonvolatile memory 1 via the memory interface 3, and the block data from the system control unit 4 in the data buffer 22 is transferred to the physical memory address E. Is transferred (steps B9 and B10).
[0103]
That is, in this memory read processing, when data is written to the virtual sector address by associating a physical sector address that is not used by all blocks with a virtual sector address that is not yet associated with the sector address conversion table 23, Since the new physical sector association process becomes unnecessary, the write processing speed is improved.
[0104]
FIG. 18 is a flowchart showing memory combination processing (part 1) by the memory control apparatus according to the embodiment.
[0105]
FIG. 19 is a flowchart showing memory combination processing (part 2) by the memory control apparatus according to the embodiment.
[0106]
FIG. 20 is a flowchart showing memory combination processing (part 3) by the memory control apparatus according to the embodiment.
[0107]
In this memory combining process, when a virtual sector address specified by a virtual memory address is associated with a plurality of physical sector addresses by the sector address conversion table 23, each effective block (the newest physical sector address is assigned to the plurality of physical sector addresses). This is an instruction to join a physical block) to each physical block belonging to one physical sector address.
[0108]
It is assumed that a new physical sector address and an existing physical sector address can be arbitrarily selected as the physical sector address to be combined.
[0109]
  As shown in FIGS. 18 to 20, first, the system control unit 4 via the command bus 11.Memory management unit 2When a memory combination instruction is given and a virtual memory address is transferred to the memory control unit 21 via the virtual memory address bus 12, the virtual memory address is converted into a virtual sector address A and a virtual block address B by the memory control unit 21. (Step C1).
[0110]
Next, the sector address conversion control unit 24 reads the sector address conversion table 23, and the sector address conversion table 23 searches the physical sector address group H associated with the virtual sector address A (step C2). From this physical sector address group H, a joining source physical sector address group C as a joining source is arbitrarily determined (step C3). It is assumed that the registration order of the physical sector addresses in the combination source physical sector address group C is continuous.
[0111]
Next, it is determined whether or not the source physical sector address group C is a physical sector address group composed of two or more physical sector addresses (step C4).
[0112]
If “NO” is determined in step C4, the physical sector address group to be combined does not exist and the termination process is performed. If “YES” is determined, the combined physical sector address F to be combined is determined. Is one of the combination source physical sector address group C or a new physical sector address that does not belong to the combination source physical sector address group C (step C5).
[0113]
If “YES” is determined in step C5, that is, if one physical sector address is used as the combining destination physical sector address F from the combining source physical sector address group C, When the physical sector addresses registered in the latest, for example, the physical sector addresses constituting the joining source physical sector address group C are “3”, “8” and “N”, the physical sector address “N” is the joining destination. The physical sector address F is selected (step C6).
[0114]
The selection method of the combined physical sector address F may be a method of selecting the physical sector address immediately after the physical sector address group C. In this case, each physical sector constituting the physical sector address group H corresponding to the virtual memory address is selected. The addresses are “3”, “8”, “N”, and “K”, and among these, the physical sector addresses constituting the source physical sector address group C are “3”, “8”, and “N”. "," The physical sector address "K" is selected as the combined physical sector address F.
[0115]
When the latest physical sector address of the physical sector address group H is the combined physical sector address F itself, for example, each physical sector address constituting the physical sector address group H and the combined physical sector address group C are configured. When the physical sector addresses to be performed are all “3”, “8” and “N”, the physical sector address “N” is selected as the combined physical sector address F.
[0116]
If “NO” is determined in step C5, that is, if it is specified that the joining physical sector address F is not included in the joining source physical sector address group C, the physical that is not registered in the sector address conversion table 23 The sector address is additionally registered in the block information table 25, and this physical sector address is set as the combined physical sector address F (step C7).
[0117]
Here, since there is a possibility that each block of the combined physical sector address F has been written, the combined physical sector address F is erased through the memory interface 3 (step C8).
[0118]
Then, this physical sector address D is the physical registration address at the end of the physical memory sector address group C as a new physical sector address corresponding to the virtual sector address A in the sector address conversion table 23 via the sector address conversion control unit 24. Registered in the registration order immediately after the sector address (step C9), and each physical block belonging to this new physical sector address is registered in the block information table 25 through the block information control unit 26 as a physical block that is an unwritten block. (Step C10).
[0119]
FIG. 21 is a diagram showing registration processing and deletion processing in the block information table 25 in the memory combining processing according to the embodiment.
[0120]
That is, as shown in FIG. 21, for each physical block belonging to the joining source physical sector addresses “3”, “8”, and “N” shown in p111 to p113, the joining destination physical sector as shown in p114. Each physical block belonging to the address “α” is registered in the block information table 25 as an unwritten block.
[0121]
Next, a physical block address range I, which is a range of physical block addresses to be searched for the latest written block from among the physical blocks belonging to the combination source physical sector address group C, is specified, and the physical block address An initial value (= “0”) of the range I is set (step C11). Note that it is also possible to select only an arbitrarily selected physical block address.
[0122]
Then, it is determined whether the block information of each physical sector address which is the first physical block address in the specified physical block address range I is an unwritten block or a written block, and the first determined written A physical sector address belonging to the block is detected as a physical sector address D (step C12).
[0123]
FIG. 22 is a diagram illustrating an example of detecting a physical sector address D in which a written block exists in the memory combining process according to the embodiment.
[0124]
That is, as shown in FIG. 22, when the physical sector addresses belonging to the source physical sector address group C are “3”, “8”, and “N” from the oldest registration order, the physical block address When the first physical block address of the range I is “0”, the search target block is a search string surrounded by p121, and the search order is the physical sectors belonging to the physical sector address group C. A search is made from the physical block (p122) associated with the newest address registration order, that is, the physical sector address “N” and the physical block address “0”, and then the physical sector address “8”. ", The physical block (p123) associated with the physical block address" 0 "is searched, and finally the physical sector address" 3 " Click address is "0" in the associated physical block (p124) is to be searched.
[0125]
Then, according to the registration order of the physical sector address, the written block first detected in the search string, that is, the physical block having the physical sector address “8” and the physical block address “0” is the written block. The physical sector address D, which is the physical sector address to which the written block detected in this search string belongs, is “8”.
[0126]
FIG. 23 is a diagram illustrating an example in which the physical sector address D in which a written block exists is not detected in the memory combining process according to the embodiment.
[0127]
That is, as shown in FIG. 23, each element sector address of the memory sector address group C is composed of “3”, “8” and “N” from the oldest registration, and the physical block address B is “1”. In this case, the search string is a search string surrounded by p131, and the search is sequentially performed from the block corresponding to the new physical sector address in the registration order. In this case, since the retrieved block is an unwritten block, that is, a written block is not detected, the physical sector address D is not detected.
[0128]
Then, it is determined whether or not the physical sector address D is detected in step C12 (step C13). If “YES” is determined, the current search is performed in the physical sector address D and the physical block address range I. The physical memory address E is calculated from the physical block address to which each target physical block belongs, and the physical block that is currently searched within the combined physical sector address F and the physical block address range I is The physical memory address G is calculated from the physical block address to which it belongs, and the block data is reflected (copied) from the physical memory address E to the physical memory address G via the memory interface 3. However, if the physical memory addresses E and F are the same address, data copy is not necessary (step C14).
[0129]
Then, the block information corresponding to the physical block address range I of the physical sector address F registered in the block information table 25 via the block information control unit 26 is updated to the block information indicating written, that is, “1” (Step 1). C15).
[0130]
That is, as shown in FIG. 21, every time the data of the latest written block in the physical sector address group C is copied, the step C is selected from the physical blocks belonging to the physical sector address “α” indicated by p114. The block information of the same physical block as the physical block address at which the written block exists as a result of the search is updated to “1” which is the block information indicated by p115.
[0131]
Next, it is determined whether or not the physical block address is the last block address in the physical block address range I, that is, the physical block address M (step C16), and “NO” is determined in this step C, that is, the physical block If the physical block address that is not the physical sector address address M and still belongs to the physical block address to be searched remains, it belongs to the physical block address obtained by adding 1 to the value of the physical block address that is currently searched. The block information of each physical block is continuously determined (steps C16 → C17 → C12).
[0132]
FIG. 24 is a diagram showing an example of detecting the latest written block in the memory combining process according to the embodiment.
[0133]
As shown in FIG. 24, when the top of the physical block address range I is “0” and the last is “M”, the search order is the physical block addresses “N”, “8”, and “3”. In the case of the order, the physical block indicated by p132 is a physical block detected as the latest written block from the physical blocks belonging to each physical block address.
[0134]
Next, all block information of physical blocks belonging to the combination source physical sector address group C registered in the block information table 25 via the block information control unit 26 is erased, that is, updated to “0” (step C18). However, if the joining destination physical sector address F is the latest registered address among the physical sector addresses belonging to the joining source physical sector address group C, the physical block information belonging to the physical sector address F is not erased.
[0135]
Since all of the latest written block data for each physical block address range I with respect to the combination source physical sector address group C exists in the physical block of the combination destination physical sector address F, the sector is converted via the sector address conversion control unit 24. The source physical sector address group C is deleted from the address conversion table 23 (step C19).
[0136]
However, if the combined physical sector address F is the latest registered physical sector address in the combined physical sector address group C, the physical sector address F is not deleted.
[0137]
That is, as shown in FIG. 21, when the physical sector addresses of the physical sector address group C are “3”, “8”, and “N”, the physical sector addresses indicated by p111 to p113 are obtained in step C19. That is, all of “3”, “8” and “N” are deleted from the block information table 25 and the sector address conversion table 23, but the combined physical sector address F is the latest in the combined physical sector address group C. If the registered address is “N”, only the physical sector addresses indicated by p 111 and p 112, that is, “3” and “8” are deleted from the block information table 25 and the sector address conversion table 23.
[0138]
FIG. 25 is a diagram showing registration processing and deletion processing in the sector address conversion table 23 in the memory combining processing according to the embodiment.
[0139]
As shown in FIG. 25, the virtual sector address A is “0”, and the virtual sector address “0” is assigned to the physical sector addresses “3”, “8” belonging to the physical sector address group H by the sector address conversion table 23. “N” and “K” are associated, the combined physical sector address F is “α”, and “3”, “8”, and “N” of each physical sector address belonging to the combined physical sector address group C Is selected, the new physical sector address “α” is registered immediately after the last physical sector address “N” of the source physical sector address group C indicated by p141 (p142).
[0140]
As a result, the virtual sector address “0” is temporarily associated with the physical sector address groups “3”, “8”, “N”, “α”, and “K”.
[0141]
In this case, the processing of Step C19 shown in FIG. 20 deletes the registration of the combination source physical sector address group C “3”, “8” and “N” indicated by p141 (p143). As a result, the virtual sector address A is associated with “α” and “K” of the physical sector address of the physical sector address group H in the address conversion table.
[0142]
Further, the join source physical sector address group C is “3”, “8” and “N”, the join destination physical sector address F is the existing physical sector address “N”, and the virtual sector address A is “0”. Yes, when the virtual sector address A is associated with “3”, “8”, “N”, and “K” of the physical sector addresses belonging to the physical sector address group H in the address conversion table, the steps shown in FIG. The registration of physical sector addresses “3” and “8” belonging to the source physical sector address group C is deleted by the processing of C19 (p144). As a result, the virtual sector address A is physically stored in the address conversion table. The physical sector addresses belonging to the sector address group H are associated with “N” and “K”.
[0143]
Further, the physical sector addresses belonging to the joining source physical sector address group C are “3”, “8” and “N”, the joining destination physical sector address F is “K” which is an existing physical sector, and the virtual sector When address A is “0” and virtual sector address A is associated with physical sector addresses “3”, “8”, “N”, and “K” belonging to physical sector address group H in the address conversion table, The processing of step C19 shown in FIG. 20 deletes the registration of physical sector addresses “3”, “8”, and “N” belonging to the combination source physical sector address group C indicated by p141 (p143). As a result, the virtual sector address A is associated with “K” of the physical sector address belonging to the physical sector address group H in the address conversion table.
[0144]
  Figure 26 shows the frontRecord7 is a flowchart showing processing when a physical block address to be combined is arbitrarily selected in the memory combining processing according to the embodiment.
[0145]
The flowchart shown in FIG. 26 is obtained by replacing a part of the flowcharts shown in FIGS.
[0146]
First, as shown in FIG. 26, when a selection process of a combination destination sector address, that is, a process similar to Steps C1 to C10 shown in FIG. 19 is performed (Step C20), a group of physical block addresses to be combined. The range of J is arbitrarily set (step C21). Here, the setting method of the physical block address group J is not particularly limited. For example, the physical block address B divided in the process of step C1 shown in FIG. 18 may be used, or the setting may be performed by obtaining information of the physical block address group J via the data bus 13.
[0147]
Then, the head element of the physical block address group J is set based on the physical block address range I indicating the physical block address to be combined (step C22), and the combination process, that is, the same process as steps C12 to C15 shown in FIG. Is performed (step C23). When it is determined in step C23 whether the latest written physical sector address is detected, that is, when it is determined that the physical sector address D is not detected by the same processing as in step C12 shown in FIG. Is combined with the physical block address obtained by adding 1 to the physical block address value currently being combined in the physical block address range J (steps C13 → C17 → C12).
[0148]
Then, after the process up to step C23, it is determined whether or not the physical block address range I is the final element of the physical block address group J (step C24). If it is determined “YES”, the end process is performed. It is determined as “NO”. In other words, if it is not the final element, the combination processing related to the physical block address obtained by adding 1 to the physical block address value currently being combined in the physical block address range J is performed (steps C24 → C25 → C23).
[0149]
Note that the processing of steps C18 and C19 shown in FIG. 20 is not performed. This is because the join process shown in FIGS. 18 to 20 is a process for all blocks belonging to the physical sector address of the join source, but the join process is completed within the range of a part of the physical block addresses. This is also because there is a possibility that there is a physical block that has not been subjected to the joining process for the effective block, that is, the physical block that belongs to the joining physical sector address, among the physical blocks belonging to the joining physical sector address.
[0150]
  That is, by this memory combination processing, a virtual sector address in which a plurality of physical sector addresses are associated with each other by the sector address conversion table 23 and the block information table 25.ButSince it is associated with one physical sector address, memory resources can be used effectively depending on the situation.
In addition, the sector address conversion table 23 manages the correspondence order of the physical sector addresses to the virtual sector addresses as described above, and the virtual block address B and the combination source physical sector address group during the memory combination processing. Block to be reflected to the physical block belonging to the combined physical sector address F with respect to the physical block indicated by the address of the physical sector associated with the virtual sector address A in the latest order among the physical sectors indicated by C Information.
  Therefore, the block of the physical block in which the block information is reflected in the physical block belonging to the combined physical sector address F among the physical blocks indicated by the combined physical sector address group C managed by the block information table 25 in the memory combining process. No need to update information.
[0151]
FIG. 32 is a diagram showing an example of overwriting a virtual sector in which arbitrary data write has been performed on all blocks in the conventional memory control device. FIG. Is a diagram showing a state before data is written, and FIG. 5B is a diagram showing processing for a physical sector when data is written to a virtual sector.
[0152]
First, in FIG. 32A, a virtual sector G in which arbitrary data write has already been performed on all blocks is associated with the physical sector X by the sector address conversion control unit 24. Assuming that arbitrary block data (P151) is written to the 0th block of the virtual sector G, the physical block indicated by p152 on the physical sector X to be actually written has already been written. p151) is written to the newly prepared physical block (p153) with the physical block address “0” on the physical sector Y where the physical blocks are all unwritten blocks, and the physical sector X The block data of the physical block group indicated by p154 associated with all the blocks not to be written above, that is, the block group from the first block to the Mth block of the virtual sector G is newly associated with the physical sector Y. 32 is copied to the physical block group (p155) which is the M-th block, and FIG. ) By the sector address conversion control section 24 as shown in eliminates the correspondence between the virtual sector G and the physical sector X, a new physical sector Y is associated with the virtual sector.
[0153]
  That is, assuming that the write time of one block to the physical memory is x, the read time is y, and one sector is composed of M blocks.DataThe total memory access time T1 required for the write process is:
[Expression 1]

It becomes.
[0154]
FIG. 27 is a diagram showing an example of overwriting a virtual sector in which arbitrary data write has been performed on all blocks in the memory control device according to the embodiment of the present invention. ) Is a diagram showing a state before the first data is written to the virtual sector, and FIG. 5B is a diagram illustrating the processing for the physical sector when the first data is written to the virtual sector. It is a figure which shows the state before writing the 2nd data, The figure (c) is a figure which shows the process with respect to the physical sector at the time of writing the 2nd data with respect to a virtual sector.
[0155]
First, in FIG. 27A, a virtual sector G in which arbitrary data write has already been performed on all blocks is associated with the physical sector X and the sector address conversion control unit 24 on a one-to-one basis. Here, it is assumed that arbitrary block data (p161) is written to the 0th block of the virtual sector G.
[0156]
At this time, since the physical block (p162) in the physical memory to be actually written has already been written, a new physical sector Y is prepared by the sector address conversion control unit 24 as shown in FIG. The block data (p161) is written to the 0th block on the physical sector Y, that is, the physical block (p163) whose physical block address is “0”, and the sector address conversion control unit 24 sets the physical sector Y to the virtual sector G. Newly associated. At this time, since the association between the virtual sector G and the physical sector X remains, the virtual sector G is associated with both the physical sector X and the physical sector Y. Further, either the 0th block (p162) of the physical sector X associated with the 0th block of the virtual sector G or the 0th block (p163) of the physical sector Y associated with the 0th block of the virtual sector G is also used. The block information control unit 26 manages the block information in order to determine whether the data written in is valid, that is, the latest written data.
[0157]
  As in FIG. 32, assuming that the write time of one block to the physical memory is x, the read time is y, and that one sector is composed of M blocks,DataThe total memory access time T2 required until the end of the write process is
[Expression 2]

It becomes.
[0158]
In this case, the block data (p167) from the first block to the Mth block of the physical sector X is associated with the first block to the Mth block of the virtual sector G.
[0159]
Further, in FIG. 27B, it is assumed that arbitrary data (p164) is written to the first block of the virtual sector G.
[0160]
In this case, since the first block (p165) on the physical sector Y to be actually written is empty, the new block data (p164) is the first block on the physical sector Y as shown in FIG. (P165) is a block for determining whether the data written in the first block (p166) on the physical sector X or the first block (p165) on the physical sector Y is valid. Block information is managed by the information control unit 26.
[0161]
The block data (p168) from the second block to the Mth block of the physical sector X is associated with the second block to the Mth block of the virtual sector G.
[0162]
In this case, the total memory access time T3 required until the write processing of the new block data (p164) is completed is:
[Equation 3]

It becomes.
[0163]
FIG. 28 is a diagram showing a configuration of the pointer type block information table 25 according to the embodiment.
[0164]
As shown in FIG. 28, this pointer type block information table 25 is used in place of the flag type block information table 25 shown in FIG. 6, and in the memory control device, a random block program in a sector, ie, each physical block. This block information management process is prohibited, and the block information table 25 used when the random block program is prohibited for the nonvolatile memory 1 itself.
[0165]
In this pointer type block information table 25, the information of the range of consecutive physical blocks that have not been written or have been written corresponding to this index is registered with the physical sector address as an index value under the control of the block information control unit 26. (P171), update (p172), and deletion (p173) can be performed, and the table value, that is, the physical block information, is the last physical block address value written to each physical sector or the first physical block address value not yet written. It is.
[0166]
  For example, when an unwritten head physical block address value is registered in the pointer-type block information table 25, the relationship between the physical sector address and the physical block address value indicated by p174 indicates that the physical sector address B is the physical block address. Unused from β to the final blockTheThe relationship between the physical sector address and the physical block address value indicated by p175 indicates that the physical sector address A is unused from the physical block address α to the last block of the sector.
[0167]
In addition, when the last physical block address that has been written is registered in the pointer-type block information table 25, the relationship between the physical sector address and the physical block address value indicated by p174 indicates that the physical sector address B is physical from the first block. The block address β indicates that it is in use, and the relationship between the physical sector address and the physical block address value indicated by p175 indicates that the physical sector address A is in use from the first block to the physical block address α. ing. However, when all the physical blocks are unused, an unused physical block address value such as “−1” is assigned.
[0168]
FIG. 29 is a diagram showing the correspondence between the virtual sector and each physical block of the physical sector in the pointer-type block information table 25 according to the embodiment, and FIG. 29A shows each physical sector having one virtual sector. It is a figure which shows the case where it is matched with a physical block, and the figure (b) is a figure which shows the case where a virtual sector is matched with each physical block of a plurality of physical sectors.
[0169]
  The correspondence between the virtual sector and each physical block of the physical sector is as follows:Sector address conversion table 23, The virtual sector K (p181) is the physical sector address from the oldest registered order.B, AWhen the virtual sector K that is assumed to be associated with each other in order is associated with physical sector addresses A and B as indicated by p174 and p175 in FIG. 28, each block of the virtual sector and each physical block of the physical sector The correspondence with is shown.
[0170]
As for the block address value common to the virtual sector and the physical sector, an unused head block offset address value is registered, and “α” and “β” are block addresses other than the maximum physical block address “M”. It is assumed to be a value.
[0171]
As shown in FIG. 29A, when “α”> “β”, as shown in p182, from block 0 of the virtual sector K to block β−1, from block 0 of the physical sector address B to β -1 block corresponds, and as shown at p183, from "β" block to "α-1" block, from "β" block to "α-1" block of physical sector address A, as shown at p184 In addition, “α” to “M” blocks are associated with unused blocks.
[0172]
As shown in FIG. 29 (b), when “α” ≦ “β”, the physical sector address from the “0” block to the “β-1” block of the virtual sector K is shown as p185. B from “0” block to “β−1” corresponds, and as shown in p186, “β” to “M” blocks are associated with unused blocks.
[0173]
That is, in the case shown in FIG. 29A, the block address range of the physical sector address A associated with the virtual sector K does not overlap with the range of the physical sector address B also associated with the virtual sector K. Therefore, each virtual block of the virtual sector K is associated with each physical block belonging to the physical sector address A and the physical sector address B. In the case shown in FIG. 29B, the virtual block is associated with the virtual sector. Since the range of the block address of the physical sector address A is included in the range of the physical sector address B that is also associated with the virtual sector, each virtual block of the virtual sector K is different from each physical block of the physical sector address A. Not associated with each physical block belonging to the physical sector address B.
[0174]
FIG. 30 is a flowchart showing a memory erase process by the memory control apparatus according to the embodiment.
[0175]
  As shown in FIG. 30, first, from the system control unit 4 via the command bus 11Memory management unit 2When a memory erase command (erase command) is given to the virtual memory address and the virtual memory address is transferred to the memory control unit 21 via the virtual memory address bus 12, the virtual memory address is transferred to the virtual sector address A and the virtual sector by the memory control unit 21. It is divided into block address B (step D1).
[0176]
Next, the sector address conversion control unit 24 reads out the sector address conversion table 23, compares the sector address conversion table 23 with the virtual sector address A, and It is determined whether there is a physical sector address group C composed of a plurality of physical sector addresses (steps D2 and D3).
[0177]
If “NO” is determined in step D3, that is, if the physical sector address group C associated with the virtual sector address A does not exist, the virtual sector address A is not associated with any physical sector, that is, an erase target. Since there is no, end processing is performed.
[0178]
  On the other hand, it is determined as “YES” in step D3, that is, the physical sector address group C associated with the virtual sector address AButIf it exists, all block information of the physical sector address group C registered in the block information table 25 via the block information control unit 26 is erased, that is, updated to “0” (step D4).
[0179]
Then, the physical sector address group C is deleted from the sector address conversion table 23 via the sector address conversion control unit 24 (step D5).
[0180]
By this memory erase process, the virtual sector address A is not associated with all physical sector addresses. At this time, when the virtual sector address A is read, the corresponding physical block address group does not exist, so that each block data of an appropriate physical sector address subjected to the erasure process is transferred.
[0181]
  That is, by this memory erase process, the information on the virtual sector address to be erased is deleted from the sector address conversion table 23 and the block information table 25, and the data of the associated physical sector address group is deleted from the memory.DoAs a result, the erase processing speed is improved.
[0182]
FIG. 31 is a diagram showing a memory copy process and a memory move process in the sector address conversion table 23 provided in the memory control device according to the embodiment.
[0183]
The memory copy process is a process of associating a physical sector address group associated with a copy source virtual sector address with a copy destination virtual sector address while keeping the association with the copy source virtual sector address. In other words, all the physical block information associated with the copy source virtual sector address is also associated with the copy destination virtual sector address by this memory copy process.
[0184]
In addition, the memory migration process is a process of eliminating the association between the physical sector address group associated with the migration source virtual sector address and the migration source virtual sector address and associating it with the copy destination virtual sector address. Through this memory migration process, all physical block information associated with the migration source virtual sector address is associated with the migration destination virtual sector address.
[0185]
Here, the transfer source virtual sector, the transfer destination virtual sector, and the means for specifying whether to copy or move are not considered.
[0186]
First, memory copy processing by the memory control device will be described.
[0187]
  As shown in FIG. 31, in the sector address conversion table 23, the transfer source virtual sector address A is associated with “3”, “8” and “N” of the physical sector address group (p191), and the transfer destination virtual sector address A When the sector address B is associated with another physical sector address group (p192) and all block data associated with the virtual sector address A is copied to the virtual sector address B, that is, from the system control unit 4 Via command bus 11Memory management unit 2When a memory copy command is given to the memory control unit 21 and the copy source and copy destination virtual memory addresses are transferred to the memory control unit 21 via the virtual memory address bus 12, they are associated with the virtual sector address B, that is, as shown in p192. Block information of all physical blocks in the physical sector address group is deleted, all data in the physical sector address group shown in p191, that is, belonging to physical sector addresses “3”, “8”, “N”, and virtual sectors All physical block addresses associated with address A and their block information are associated with virtual sector address B.
[0188]
At this time, since the virtual sector address B is associated with the same physical sector as the virtual sector address A, when the block data of the physical sector is changed, a new copy of all block data of the physical sector to be changed is copied. It is assumed that the processing is performed by using the physical sector and replacing the registration in the sector address conversion table 23.
[0189]
Next, memory movement processing by the memory control device will be described.
[0190]
  Similarly, in the sector address conversion table 23, the transfer source virtual sector address C is associated with “9”, “2”, and “5” of the physical sector address group (p193) in the sector address conversion table 23, and the transfer When the destination virtual sector address D is associated with another physical sector address group (p194) and all block data associated with the virtual sector address B is moved to the virtual sector address B, that is, the system control unit 4 through the command bus 11Memory management unit 2When a memory move command is given to the virtual memory address and the virtual memory address of the migration source and destination is transferred to the memory control unit 21 via the virtual memory address bus 12, it is associated with the virtual sector address D, that is, as shown in p194. The block information and all the physical blocks in the physical sector address group are deleted, all data in the physical sector address group shown in p193, that is, belong to the physical sector addresses “9”, “2”, “5”, and All physical block addresses and block information associated with the sector address C are associated with the virtual sector address D, and the association between the virtual sector address C and the physical sector address group (p193) is lost.
[0191]
In other words, when copying all block data from any virtual sector to any virtual sector or moving all block data from any virtual sector to any virtual sector by these memory copy processing or memory migration processing. Even in such a case, data copy or data movement on the non-volatile memory 1 does not occur, so the processing can be speeded up.
[0192]
Therefore, according to the memory control device having the above configuration, the virtual address to be written by the memory write process after one virtual sector is associated with a plurality of physical sectors by the sector address conversion table 23 and the block information table 25. A physical sector address in which an appropriate unwritten block exists is detected from the physical sector address group associated with the sector address, and the physical sector address group associated with the virtual sector address to be written by memory read processing A physical sector address in which an appropriate written block exists is detected, and a virtual sector address in which a plurality of physical sector addresses are associated with each other in the sector address conversion table 23 and the block information table 25 by the memory combining process. , One physical sector address The physical sector address group corresponding to the virtual sector address to be erased is deleted by the memory erase process, and the virtual sector address and the physical sector on the sector address conversion table 23 are deleted by the memory copy process and the memory move process. Since the address association information is rewritten, it is possible to shorten the processing time related to memory reading and writing and to efficiently use memory resources.
[0193]
【The invention's effect】
  As described above, the present inventionInAccording to the memory management system involved, eachMultiple physical blocks as write unitsHaveMultiple physical sectors as erasure unitsPhysical memoryandCorresponds to the physical sector of the physical memoryMultiple virtual sectorsA memory management method for managing reading and writing of data using a virtual memory having a virtual sector address and a single or a plurality of physical sector addresses.For each virtual sector addressA sector address management means to be associated;Order management means for managing the order of timing of correspondence of each address of a plurality of physical sectors associated with the address of the virtual sector by this sector address management means;Block information management means for managing block information indicating a use state of a physical block belonging to a physical sector;First calculation means for calculating the address of the physical block indicated by the virtual memory address to be written with data, second calculation means for calculating the address of the virtual sector indicated by the virtual memory address to be written, and block information management Based on the block information managed by the means and the order managed by the order management means, each address of the physical sector associated with the virtual sector address calculated by the second calculation means by the sector address management means and the first The virtual sector address calculated in the slowest order among the physical blocks in use corresponding to the address calculated by one calculating means is in an order after the physical sector address associated by the sector address managing means. Sector address for the calculated virtual sector address As the address of the physical sector write target address of the associated physical sector by physical meansSector address detecting means for detectingThe sector address management means newly associates with the address of the virtual sector that has calculated the address of the physical sector in which all physical blocks belonging to the case where the address is not detected by the sector address detection means. The order management means manages the address of the newly associated physical sector as being associated with the calculated virtual sector address in the latest order by the sector address management means. Sector address designating means for designating the address of the physical sector to be written, and the block information management means is the address designated by the sector address designating means and the address of the physical block calculated by the first computing means. Indicates the usage status of the block information of the identified physical block To be rewritten to broadcastBecome.
[0198]
  Therefore, the present invention shortens the processing time related to reading and writing of the non-volatile memory, and enables efficient use of memory resources..
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a memory control device according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a memory management unit provided in the memory control device according to the embodiment.
FIG. 3 is a diagram showing a configuration of a sector address conversion table provided in the memory control device according to the embodiment.
FIG. 4 is a diagram showing an example of correspondence between virtual memory and physical memory by a sector address conversion table provided in the memory control device according to the embodiment.
FIG. 5 is a view showing an example of correspondence between virtual sectors and physical sectors according to the embodiment;
FIG. 6 is a diagram showing a configuration of a block information table provided in the memory control device according to the embodiment.
FIG. 7 is a flowchart showing memory write processing (part 1) by the memory control apparatus according to the embodiment;
FIG. 8 is a flowchart showing memory write processing (part 2) by the memory control apparatus according to the embodiment;
FIG. 9 is a diagram showing an example in which a physical sector address D in which an unwritten block exists is detected in the memory write processing according to the embodiment.
FIG. 10 relates to the embodiment.Memory lightThe figure which shows the example which cannot detect the physical sector address D in which the unwritten block exists in a process.
FIG. 11 is a view showing block information update processing in a block information table according to the embodiment;
FIG. 12 is a diagram showing a new physical sector address registration process for the block information table according to the embodiment and a block information update process associated with the registration process.
FIG. 13 is a flowchart showing memory read processing (part 1) by the memory control device according to the embodiment;
FIG. 14 is a flowchart showing memory read processing (part 2) by the memory control apparatus according to the embodiment;
FIG. 15 is a diagram showing an example in which a physical sector address D in which a written block exists is detected in the memory read processing according to the embodiment.
FIG. 16 shows a physical sector address D in which a written block exists in the memory read process according to the embodiment.AbsentThe figure which shows an example.
FIG. 17 is a view showing registration processing of a new physical sector address with respect to the block information table according to the embodiment.
FIG. 18 is a flowchart showing memory combination processing (part 1) by the memory control apparatus according to the embodiment;
FIG. 19 is a flowchart showing memory combination processing (part 2) by the memory control device according to the embodiment;
FIG. 20 is a flowchart showing memory combination processing (part 3) by the memory control apparatus according to the embodiment;
FIG. 21 is a view showing registration processing and deletion processing in the block information table in the memory combining processing according to the embodiment;
FIG. 22 is a diagram showing an example of detecting a physical sector address D in which a written block exists in the memory combining process according to the embodiment.
FIG. 23 is a diagram showing an example in which a physical sector address D in which a written block exists is not detected in the memory combining process according to the embodiment.
FIG. 24 is a view showing a detection example of the latest written block in the memory combining process according to the embodiment;
FIG. 25 shows registration processing and deletion processing in the sector address conversion table in the memory combining processing according to the embodiment.Figure.
FIG. 26RecordIn the memory combining process according to the embodiment, a process when arbitrarily selecting a physical block address to be combined is shown.flowchart.
FIG. 27 is a diagram showing an example of overwriting a virtual sector in which arbitrary data write has been performed on all blocks in the memory control device according to the embodiment of the present invention; ) Is a diagram showing a state before the first data is written to the virtual sector, and FIG. 5B is a diagram illustrating the processing for the physical sector when the first data is written to the virtual sector. It is a figure which shows the state before writing the 2nd data, The figure (c) shows the process with respect to the physical sector at the time of writing the 2nd data with respect to a virtual sector.Figure.
FIG. 28 is a diagram showing a configuration of a pointer-type block information table according to the embodiment.
FIG. 29 is a diagram showing a correspondence between a virtual sector and each physical block of a physical sector in the pointer-type block information table according to the embodiment, and FIG. 29A shows each physical sector having one virtual sector. It is a figure which shows the case where it is matched with a physical block, and the same figure (b) is a figure which shows the case where a virtual sector is matched with each physical block of a some physical sector.
FIG. 30 is a flowchart showing a memory erase process by the memory control device according to the embodiment;
FIG. 31 is a view showing a memory copy process and a memory move process in a sector address conversion table provided in the memory control device according to the embodiment;
FIG. 32 is a diagram showing an example of overwriting a virtual sector in which arbitrary data write has been performed on all blocks in the conventional memory control device. FIG. FIG. 5B shows a state before data is written to the physical sector, and FIG. 5B shows processing on the physical sector when data is written to the virtual sector.Figure.
[Explanation of symbols]
1 Non-volatile memory
2. Memory management unit
3. Memory interface
4 ... System control unit
11 ... Command bus
12 ... Virtual memory address bus
13 Data bus
14 ... Memory access command bus
15 ... Physical memory address bus
16 ... Memory data bus
17 ... Memory bus
21 ... Memory control unit
22 ... Data buffer
23 ... Sector address conversion table
24 ... Sector address conversion control unit
25 ... Block information table
26: Block information control unit

Claims (6)

Using virtual memory, each formed by a plurality of virtual sectors correlated with multiple has been made physical memory and the physical sector of the physical memory physical sector formed by a plurality as a unit writes the physical block as an erase unit A memory management method for managing reading and writing of data,
A sector address management means for associating the address of the virtual sector address and a single or a plurality of the physical sector in each address of the virtual sector,
Order management means for managing the order of timing of correspondence of each address of a plurality of physical sectors associated with the address of the virtual sector by the sector address management means;
And block information management means for managing block information indicating the use state of the physical blocks belonging to the physical sector,
First calculation means for calculating an address of a physical block indicated by a virtual memory address to which data is to be written;
Second calculating means for calculating an address of a virtual sector indicated by the virtual memory address to be written;
Based on the block information managed by the block information management means and the order managed by the order management means, the sector address management means associates the virtual sector address calculated by the second calculation means. The sector address management means associates the calculated virtual sector address in the slowest order among the physical blocks in use corresponding to each address of the physical sector and the address calculated by the first calculation means. Sector address detecting means for detecting, as the address of the physical sector to be written, the address of the physical sector associated by the sector address management means with respect to the calculated virtual sector address in the order after the physical sector address. It has a door,
The sector address management means newly associates the address of the physical sector in which all the physical blocks to which it belongs is unused with the calculated virtual sector address when no address is detected by the sector address detection means. ,
The order management means manages that the address of the newly associated physical sector is associated with the calculated virtual sector address in the latest order by the sector address management means,
Sector address designating means for designating the address of the newly associated physical sector as the address of the physical sector to be written;
The block information management means rewrites the block information of the physical block specified by the address specified by the sector address specifying means and the address of the physical block calculated by the first calculation means into information indicating a use state. /> A memory management method characterized by this.   The sector address management means newly associates the address of a physical sector in which all physical blocks to which it belongs to an unused virtual sector with an address of an arbitrary virtual sector,
  The order management means manages that the address of the newly associated physical sector is associated with the calculated virtual sector address in the latest order by the sector address management means,
  The block information management unit calculates the calculation among physical blocks belonging to a physical sector that is associated with the address of the arbitrary virtual sector by the sector address management unit and indicated by an address different from the newly associated address. The block information of the physical block indicated by the address managed by the order management means when associated with the virtual sector address in the latest order by the sector address management means has the same address as the address of the physical block. And reflected in the physical block belonging to the physical sector indicated by the newly associated address,
  2. The memory management system according to claim 1, wherein the sector address management unit deletes the association between the address of the arbitrary virtual sector and the address of the reflection source physical sector.   The sector address management means searches for an address managed by the order management means as being associated in the slowest order among physical sector addresses associated with an arbitrary virtual sector address,
  The block information management unit is configured to correspond to the calculated virtual sector address among physical blocks belonging to a physical sector associated with the address of the arbitrary virtual sector and indicated by an address different from the searched address. The block information of the physical block indicated by the address managed by the order management means that is associated in the latest order by the address management means is indicated by the retrieved address having the same address as the address of the physical block. Reflected in the physical block belonging to the physical sector,
  2. The memory management system according to claim 1, wherein the sector address management unit deletes the association between the address of the arbitrary virtual sector and the address of the reflection source physical sector.   A non-volatile memory, a physical sector having a plurality of physical sectors each having a physical block as a writing unit in the non-volatile memory, and a virtual sector associated with the physical sector of the physical memory A memory management device that manages the reading and writing of data using a virtual memory comprising a plurality of
  Sector address management means for associating the address of the virtual sector with the address of the single or plural physical sectors for each address of the virtual sector;
  Order management means for managing the order of timing of correspondence of each address of a plurality of physical sectors associated with the address of the virtual sector by the sector address management means;
  Block information management means for managing block information indicating a use state of a physical block belonging to the physical sector;
  First calculation means for calculating an address of a physical block indicated by a virtual memory address to which data is to be written;
  Second calculating means for calculating an address of a virtual sector indicated by the virtual memory address to be written;
  Based on the block information managed by the block information management means and the order managed by the order management means, the sector address management means associates the virtual sector address calculated by the second calculation means. The sector address management means associates the calculated virtual sector address in the slowest order among the physical blocks in use corresponding to each address of the physical sector and the address calculated by the first calculation means. Sector address detecting means for detecting, as the address of the physical sector to be written, the address of the physical sector associated by the sector address management means with respect to the calculated virtual sector address in the order after the physical sector address And
  The sector address management means newly associates the address of the physical sector in which all the physical blocks to which it belongs is unused with the calculated virtual sector address when no address is detected by the sector address detection means. ,
  The order management means manages that the address of the newly associated physical sector is associated with the calculated virtual sector address in the latest order by the sector address management means,
  Sector address designating means for designating the address of the newly associated physical sector as the address of the physical sector to be written,
  The block information management means is a physical block specified by the address designated by the sector address designation means and the physical block address calculated by the first calculation means. The block information of the rack to the information indicating the usage status
A memory management device.   The sector address management means newly associates the address of a physical sector in which all physical blocks to which it belongs to an unused virtual sector with an address of an arbitrary virtual sector,
  The order management means manages that the address of the newly associated physical sector is associated with the calculated virtual sector address in the latest order by the sector address management means,
  The block information management unit calculates the calculation among physical blocks belonging to a physical sector that is associated with the address of the arbitrary virtual sector by the sector address management unit and indicated by an address different from the newly associated address. The block information of the physical block indicated by the address managed by the order management means when associated with the virtual sector address in the latest order by the sector address management means has the same address as the address of the physical block. And reflected in the physical block belonging to the physical sector indicated by the newly associated address,
  5. The memory management apparatus according to claim 4, wherein the sector address management unit deletes the association between the address of the arbitrary virtual sector and the address of the reflection source physical sector.   The sector address management means searches for an address managed by the order management means as being associated in the slowest order among physical sector addresses associated with an arbitrary virtual sector address,
  The block information management unit is configured to correspond to the calculated virtual sector address among physical blocks belonging to a physical sector associated with the address of the arbitrary virtual sector and indicated by an address different from the searched address. The block information of the physical block indicated by the address managed by the order management means that is associated in the latest order by the address management means is indicated by the retrieved address having the same address as the address of the physical block. Reflected in the physical block belonging to the physical sector,
  5. The memory management apparatus according to claim 4, wherein the sector address management unit deletes the association between the address of the arbitrary virtual sector and the address of the reflection source physical sector.

Images