DE102006058511A1 - Method for receiving message by portable data carrier, involves transferring partial messages into temporary buffer of data carrier, which is available in starting buffer - Google Patents

Abstract

The method involves transferring partial messages into a temporary buffer (16) of the data carrier, which is available in a starting buffer. The memory of partial messages in a non-volatile Electrically Erasable Programmable Read-Only Memory (5) of the data carrier is available in the temporary buffer, such that a complete message is formed from the partial messages. The transferring and memory are synchronized such that partial messages from the temporary buffer are stored in the non-volatile memory, where starting buffer does not exceed a given level.

Description

The The present invention relates to a method for receiving messages through a portable disk and such a data carrier, in particular a chip card, a secure multimedia card, a USB storage medium, a mobile phone card or similar.

in the Area of data communication between portable data carriers and corresponding reading / writing devices or terminals is due to new applications and requirements the need arose to receive and send messages whose Length the usual from portable data carriers exceeds processable message lengths.

It are different possibilities known to receive overlong To allow messages through a portable volume. On the one hand, it is possible, to increase the reception / transmission buffers used, but at an increased cost leads, since receiving buffer usually be realized as expensive RAM memory. It is also possible to receiving overlong Splitting messages before they are sent by the sender that they are from the disk can be received and processed step by step ("off-card splitting") the disadvantage that on the one hand comparatively complex transmission protocols must be used and on the other hand each terminal communicating with such portable media should be converted must be limited to it options the disk adapt.

EP 0 811 204 B1 discloses a method wherein oversized messages are stored in a non-volatile memory configured as an EEPROM. It is distinguished between an immediate and an indirect storage of excess messages in the EEPROM memory, the indirect storage is done via the detour of a RAM memory in order to preprocess messages there before the final storage can. Here, however, there is the problem that an EEPROM memory has only small storage times and the data carrier is limited in data reception by the memory speed of its EEPROM memory.

Generally exists in such solutions often the additional Problem that with the sequential receipt of partial messages a Message a performance loss is expected as the processor of the disk must coordinate the sequential data input and meanwhile do not take on any other tasks can. Therefore, it is desirable in digital data transmission, the inclusion of message blocks an incoming stream of data from the speed of the processor of the receiving volume and decouple from its clock rate, so that the sending communication partner the disk the At least to a certain extent. For this become common separate, asynchronous input buffers, such as. B. UART devices ("Universal Asynchronous Receiver / Transmitter "), which can be received by the data carrier Can directly record part messages. The function of such UART blocks is thus independent from the processor speed and needed for byte-level communication no software support. The receipt of long messages supports an asynchronous input buffer, however, not because it is in smart cards usually summarizes only amounts of data the size of a byte.

It Therefore, the object of the present invention is an efficient Receive overlong messages through a disk to enable.

These The object is achieved by a Method and a portable data carrier with the features of the independent claims solved. In it dependent claims are advantageous embodiments and developments of the invention specified.

One according to the invention, with A portable medium equipped with a processor includes a non-volatile one Memory and an asynchronous input buffer that is continuous and sequentially (eg, bit or byte wise) submessages of a to be received overlong Message independent from the processor of the volume receives. In the asynchronous input buffer present sub-messages first transferred to an intermediate buffer of the volume, which is the overlong Message under circumstances not completely and from there in the sufficiently large non-volatile Memory of the data carrier saved. When saving, the overlong message is in non-volatile Memory merged from their sub-messages.

In this case, the steps of transmitting partial messages from the input buffer into the intermediate buffer and storing partial messages in the intermediate buffer into the non-volatile memory are performed in a coordinated and synchronized manner so that partial messages present in the intermediate buffer can only be stored in the non-volatile memory as long as the input buffer does not exceed a predetermined level. When the predetermined level of the continuously filling input buffer is reached, the Teilnachrich present therein prioritized into the intermediate buffer.

The Steps of transferring and storing are further synchronized so that partial messages can be transferred from the input buffer to the intermediate buffer when the input buffer exceeds a predetermined level, d. h. that in the Between buffer always enough free space available is to present in the input buffer part messages without buffer overflow or transfer data loss in the intermediate buffer.

Of the Advantage of the present invention is that by the above-described synchronized filling and emptying of the series switched asynchronous input buffers, intermediate buffers and for extra long News big enough non-volatile memory, neither an increase in itself sufficient huge Input or intermediate buffer still splitting up too long Messages required by the sender. The transmitter can be his Message rather block by block sequential and without prior splitting to the disk Send, where they as a result of the synchronized further treatment of in the input buffer incoming partial messages continuously recorded in bit or byte by byte from the input buffer without data loss can be. Here you can the proven ones Communication protocols (eg T = 0 and T = 1 in the chip card area) unchanged be used. About that In addition, the processor has no dead times as it is processing Execute processes can, while the input buffer fills with new partial messages.

Preferably the asynchronous input buffer is a UART block ("Universal Asynchronous Receiver / Transmitter "), which does not respond to the speed or clocking the processor of the disk is bound, as the message reception on Hardware level is realized. Such a UART module has a relatively small data capacity of usually only one byte.

Of the The intermediate buffer is preferably one set up in a RAM memory of the data carrier Buffer area whose size is that of the Exceeds input buffer. Preferably, the intermediate buffer is realized as a ring memory, through coordinated writing and reading processes in the FIFO principle ("first in first out ") continuously filled with data and can be emptied.

Thereby can the fast and the opposite Input buffer larger RAM intermediate buffer a bridging function between the small, asynchronous input buffer and the large, relatively slow one adopt non-volatile memory, whereby a coordinated recording of sub-messages is made possible. A direct series connection of the input buffer and the non-volatile Memory, without the bridging buffer, could In contrast, due to the discrepancy between the transfer rate of incoming submessages in the input buffer and the memory speed of the non-volatile Memory to Buffer Overflows and Data loss lead. In addition, the writing speed can be optimized, as the non-volatile memory is described page by page and the size of the input buffer usually smaller than the page size of the non-volatile memory.

One portable according to the invention disk further comprises an input-side processor executable by the processor is set up so that they are transmitted by alternation of sub-messages present in the input buffer into the intermediate buffer and storing submessages present in the intermediate buffer in the non-volatile memory, a message receiving such synchronizes that the intermediate buffer is not completely filled, when the input buffer exceeds a predetermined level. Furthermore leads the input control the transferring and storing so alternately through, on the other hand, too the input buffer is not complete filled is, if not all partial messages of the message to be received have arrived. These two synchronization conditions guarantee the smooth running of a message reception from the recording from partial messages in the input buffer to the presence of the fully assembled message in non-volatile memory.

The Input control realizes the two steps of copying and of reading out as separate, competing processes by means of a Multitasking / multithreaded Operating system of the disk. The arrival of partial messages in the input buffer and / or the crossing the predetermined level is registered by an interrupt device of the data carrier, which then triggers an interrupt signal ("interrupt") causes the processor to temporarily interrupt the currently executing process and the message reception priority.

Once the interrupt device triggers an interrupt signal, an interrupt processing interrupt process is performed by the input controller to transmit sub messages present in the input buffer to the intermediate buffer. When the interruption process has transferred a given volume of data and / or all submessages present in the input buffer to the intermediate buffer, it terminates its work until new part again present messages in the input buffer and / or a certain predetermined level of the input buffer is reached or exceeded. Thereafter, the input controller activates a memory process which stores sub-messages present in the intermediate buffer in the nonvolatile memory of the data carrier. As a result, the intermediate buffer is at least partially emptied, so that the interruption process can refill it if necessary.

The Partial messages are stored by the storage process in this way and put together that, after all Have received submessages of an overlong message to be received, this message completely in non-volatile memory. There will be the complete message an application for which the message is intended is.

Before the message of an application assembled in the non-volatile memory can be verified, z. B. by the Storage process. This verification can be one of the normal processing the test upstream of the message include, for example, the verification of a checksum or the performing a cryptographic or other safety-related operation. The message may preferably be from the storage process in one in the non-volatile memory, sufficiently large separate memory area together that will not be the final one Location of the received message. This is special then helpful if the received message is a Update instruction from in non-volatile storage already existing data, which is a direct overwriting of the final Storage locations could not be reconstructed if z. B. the verification the message fails by checking a checksum or the Message due to a transmission error incomplete is.

Preferably the sub-messages present in the intermediate buffer are matched with a storage management of the volume page by page in the non-volatile Memory written.

Around execution the interruption and storage processes by the input control To effectively synchronize, the volume includes a Multitasking / multithreaded Operating system, which can run processes / threads concurrently on the processor, so that the input control is a concurrent execution of the interruption process and the storage process. The execution of a Interruption process can then be interrupted to stop the execution of an interrupted Continue storage process when the interruption process Has emptied input buffer. Conversely, the storage process is interrupted, to continue the interrupt process when the input buffer exceeds the predetermined level.

In addition to the interrupt process and the storage process, the controller execution of a protocol process, which one in the intermediate buffer present sub-message interpreted by a z. B. for the execution of Storage process needed Information determined from the partial messages of the buffer becomes. Such information may be in particular a length information about the Length of Message and / or structure information about the structure of the message act.

Of the Protocol process can by evaluating certain bytes of a partial message determine if the partial message belongs to an overlong message, so that the storage process for handling the partial messages accordingly here over can be informed. For example, this treatment can be exist in the separate memory area of the partial message non-volatile memory or transfer it to already received partial messages to add. Likewise, the interpretation in a pure validation of the received submessages insist on data transmission errors early to recognize.

To the interpretation of a sub-message present in the intermediate buffer the protocol process is interrupted by the input control or stopped and the storage process continued or started, taking the storage process the information determined by the protocol process uses.

at a multitasking / multithreaded operating system will use the execution the interruption process on the one hand and the protocol process on the other and / or the storage process otherwise synchronized, that the execution the logging process and / or the storage process or continues and the execution of the interrupt process terminated or interrupted when the intermediate buffer due the sub-message transmission the interruption process exceeds a predetermined maximum level. Preferably, the storage process is started when the input buffer crowded.

Accordingly, the input controller suspends or terminates the execution of the interpretation process and / or the storage process, and suspends execution of the interrupt pro cesses continues or starts when the input buffer exceeds a predetermined level due to the continuous filling with further sub-messages and / or if the intermediate buffer falls below a predetermined minimum level as a result of the operation of the storage process.

to smooth processing of receiving an overlong message is it Consequently, it is necessary to continuously check whether, on the one hand, in the Input buffer sub-messages are present and / or a predetermined Level exceeded and on the other hand, if the intermediate buffer has enough memory space to receive partial messages from the input buffer or memory space must be created.

The passing a predetermined level of the input buffer is signaled interrupt (using "interrupts"), so that neither the input control nor the operating system of the data carrier Presence of sub-messages in the input buffer. Of the Intermediate buffer is in contrast preferably monitored by an event control event-controlled, wherein a falling below a minimum level or exceeding a maximum level by means of a level signal (an "event") of the input control is communicated.

The Treatment of a message to be received is on arrival of the first part messages in principle by an interruption and Activation of the corresponding interruption process by the Input control initiated. The further from the input control activated and / or continued processes are due to their different importance with different execution priorities. It makes sense to compare the interruption process with that highest to the other processes Equip execution priority, because this when Einfref fen of sub-messages in the small input buffer immediately must react.

Of the to be activated after termination / interruption of the interruption process Protocol process is run with a medium execution priority and the to be activated after termination / interruption of the protocol process Storage process started with a low execution priority / continued. Overall, however, the operating system of the disk ensures that all other processes to be executed by the processor during processing an input of sub messages in relation to the three above Processes each have lower execution priorities.

The Input control can be either as part of the operating system or of the privileged operating system kernel as well as independent of Operating system of the data carrier be realized. In addition to the use of processes by the It is also possible to activate the input control Provide input control in turn as an input / output process, in each case an interrupt thread, a protocol thread and a memory thread for performing the above Tasks synchronized to be activated. The input / output process can then act as a process to be activated by the kernel be designed.

When Inventive disk is in particular a chip card, a secure multimedia card, a USB storage medium, a mobile card or the like provided.

Even though the above description explains only the data reception is the inventive Principle unrestricted Also applicable to sending data to the secondary buffer is set up as a virtual output buffer.

Further Features and advantages of the invention will become apparent from the following Description of various inventive embodiments and alternative embodiments in conjunction with the accompanying drawings. Show:

1 a smart card equipped to efficiently receive long messages with a RAM ring buffer;

2 a method for receiving messages by the in 1 illustrated smart card;

3 a smart card equipped for efficient message reception with a secondary buffer as a virtual input buffer; and

4 a method for receiving messages by the in 3 shown chip card.

The following description of the figures explains a method and an apparatus for receiving overlong messages by a portable data carrier, which is illustrated in the figures by a chip card with processor. The method consists of two, individually or in combination deployable sub-procedures, each in the 2 and 4 are shown while the 1 and 3 the, the respective sub-procedure realizing chip card shows. The possibility of combining the methods of 2 and 4 and the devices of 1 and 3 is also expressed by the fact that matching process steps and / or components are provided in the figures with the same reference numerals.

The in the 1 and 3 The chip cards shown are suitable without restriction both for receiving and for sending messages, the receiving method of the 2 and 4 to the news broadcast principle in reverse order by the same components can be realized. In this respect, the figures and the following description do not represent a restriction of the invention to the message reception, but describe this only as an example and are therefore also applicable to the news broadcast.

in the Chip card area have for data transmission and communication with external readers, Terminals or other communication partners the transmission protocols T = 0 and T = 1 established which standardized block-oriented half-duplex protocols for mobile phone cards and chip cards represent. In this case, the byte-oriented T = 0 protocol becomes predominantly for GSM mobile smart card used while the T = 1 protocol for other chip cards and chip card-like portable data carriers are used becomes.

at a smart card operating system, which is a multitasking (or Multithreading), become several protected Pozesse ("tasks") or process threads ("threads") through frequent process or thread change seemingly simultaneously, running concurrently. One Process usually includes an address space and at least one Process thread. In the following description is for the from the Processor of the chip card concurrent to be processed in the context of the treatment of an incoming message mainly spoken by processes that kernel of the operating to be activated. The same tasks can also be done by threads if the operating system is a multithreaded operating system is. The overhead of threads is common less than that for Processes, as there is no change in a thread complete Context change (states, Register contents, etc.) must be made, because concurrent threads Partial tasks of a process and a common part of the process context. A communication between tasks is possible using interprocess communication (IPC). threads which are assigned to the same process, can synchronize using the IPC. All explained in this description functionalities and tasks are alike as processes or as threads realizable, whereby, apart from the described administrative differences, also the Advantages and disadvantages of processes and threads with regard to the present invention are comparable.

1 shows a chip card 1 , which is adapted to efficiently receive and transmit messages that are too long over the capacity of conventional reception / transmission memories or buffers intended for data communication. The chip card 1 includes as common hardware components a processor 2 (CPU), a communication interface 3 , a UART input buffer 18 and a memory arrangement consisting of a permanent ROM memory 4 , a non-volatile EEPROM memory 5 and a volatile RAM memory 6 , The chip card 1 comprises a total of three buffers in series to receive and handle incoming long messages: The UART device 18 , which is a separate hardware chip in the smart card 1 integrated, an intermediate buffer 16 who is at the in 1 illustrated embodiment as a ring buffer in the RAM memory 6 is created, and finally a separate memory area 14 (NVM) in nonvolatile EEPROM memory 5 , The UART device 18 can support a suitable protocol, such as USB or MMC.

Furthermore, the chip card includes 1 an operating system 7 which is usually in permanent ROM memory 4 is stored. The operating system 7 includes the kernel 8th (KERNEL), which in addition to other basic tasks of an operating system also has an interrupt control 9 as an "interrupt handler." Likewise, an input control 10 (I / O-CNTL), which processes incoming partial messages of a message by synchronized activation of different processes, and event control 11 (EVENT), which treats specific events ("events") by calling associated event handlers ("event handlers") as part of the operating system 7 realized. While the interruption treatment 9 usually a part of the kernel 8th is, can the event control 11 and the input control 10 of course also as parts of the kernel 8th be realized, or as in the EEPROM memory 5 Stored advanced system software or as applications.

Running applications 13 (APP), routines of the kernel 8th or processes of input control 10 leads to separate, from the processor 2 running processes or threads 19 . 20 . 21 . 22 . 24 , Here are routines and processes of the operating system kernel 8th as processes 24 in privileged system mode 26 while running from the input control 10 initiated interruption processes 20 (IR-PROC), protocol processes 21 (PRTCL-PROC) and storage processes 22 (NVM-PROC) as well as application processes 19 (APP-PROC) in restricted, safe user mode 27 be executed.

In the 1 and 2 the reception becomes ei an overlong message constructed of sub-messages B1-B8. In this context, "excess length" means that the smart card 1 can not fully accommodate the overlong message in any (RAM) buffer commonly used for this purpose. So are also at the in 1 illustrated chip card 1 the UART buffer 18 and the intermediate buffer 16 each not large enough to hold overlong messages that span more than 255 bytes.

The entire message B1-B8 is transmitted continuously by a transmitter, bit by bit sequentially via the communication interface 3 the chip card 1 in the UART input buffer 18 fed or received by this. In 1 a scenario is shown in which the reception of the overlong message B1-B8 has already progressed so far that the sub-messages B1, B2 are already in the non-volatile memory area 14 while sub messages B3, B4 in the RAM ring buffer 16 sub message B5 in the UART input buffer 18 is and the final part messages B6, B7, B8 not yet in the chip card 1 have arrived.

In connection with the 1 and 2 The term sub message is not to be understood as a standardized message block in the sense of a byte, but may in principle comprise a variable number of bits, not necessarily the size of the input buffer 18 or memory management of the operating system 7 is adjusted.

• – Zunächst nimmt der UART-Eingangspuffer 18 einige Bits einer eingehenden Nachricht als Teilnachrichten auf (30). Die eingehende Teilnachricht ist insbesondere eine Kommando-APDU („Application Protocol Data Unit") als grundlegende Kommunikationseinheit zur Datenübertragung von einem Terminal an eine Chipkarte.
• – Bei Vorliegen einer Teilnachricht in dem Eingangspuffer 18 und/oder bei Überschreiten eines vorgegebenen Füllstands des Eingangspuffers 18 wird eine Unterbrechung (Interrupt) unabhängig von dem Betriebssystemkern 24 ausgelöst, wobei eine Unterbrechungstabelle die bei dem vorliegenden Unterbrechungstyp „DATA AVAILABLE" (31) auszuführende Unterbrechungsbehandlungsroutine (ISR) bestimmt.
• – Aufgrund der ausgelösten Unterbrechung (31) unterbricht der Betriebssystemkern 24 die Ausführung des momentan von dem Prozessor 2 aus geführten Anwendungsprozesses, um den Nachrichteneingang prioritär zu bearbeiten. Durch die Unterbrechung DATA AVAILABLE wird der Unterbrechungsprozess 20 von dem Betriebssystemkern 24 mit höchster Ausführungspriorität aktiviert (32), so dass Teilnachrichten aus dem Eingangspuffer 18 in den Zwischenpuffer 16 übertragen werden, sobald der Eingangspuffer 16 einen vorgegebenen Füllstand überschreitet.
• – Der Unterbrechungsprozess 20 liest eine vorgegebene Anzahl oder alle Bits aus dem UART-Eingangspuffer 18 aus (33) und schreibt sie in den RAM-Ringpuffer 16 (34). Durch die Synchronisation der Prozesse 20, 21 und 22 wird dafür gesorgt, dass der Ringpuffer 16 niemals gänzlich gefüllt ist, wenn im UART-Eingangspuffer 18 auszulesende Daten vorliegen, da andernfalls ein Datenverlust auftreten kann.
• – Der Unterbrechungsprozess 20 wird nach Erledigung seiner Aufgabe wieder inaktiv und wartet auf die nächste Aktivierung durch eine Unterbrechung aufgrund von im Eingangspuffer 18 vorliegenden weiteren Teilnachrichten. Ebenso gut kann der Unterbrechungsprozess 20 auch wieder aktiviert werden, wenn der Zwischenpuffer 16 vollständig geleert ist, selbst wenn der UART-Eingangspuffer 18 noch nicht den zum Auslösen einer Unterbrechung erforderlichen Füllstand erreicht hat. Die Signalisierung, dass der Ringpuffer 16 vollständig geleert ist, kann durch einen Event ausgelöst werden oder dem Unterbrechungsprozess 20 durch Interprozesskommunikation (IPC) von dem Speicherprozess 22, der den Ringpuffer 16 ausliest, mitgeteilt werden.
• – Sobald der hochprioritäre Unterbrechungsprozess 16 inaktiv wird, wird der Protokollprozess 21 mit mittlerer Priorität von dem Betriebssystemkern 24 bzw. der Eingangssteuerung 10 aktiviert (35).
• – Der Protokollprozess 21, der unter Umständen bereits unmittelbar nach kontaktieren der Chipkarte mit dem Sendeterminal im Rahmen einer Initialisierungsphase der Chipkarte aktiviert wurde (der Protokollprozess sendet bei der Initialisierung eine ATR-Nachricht („Answer to Reset") an das Terminal mit diversen Chipkarten- und Übertragungsparametern, z. B. auch der Größe des Ringpuffers 16, um eintreffende übergroße Nachrichten erkennen zu können), wird nun durch den Betriebssystemkern 24 aktiviert oder fortgesetzt, falls er temporär inaktiv ist. Optional ist es auch möglich, dass der Protokollprozess 21 prüft, ob Teilnachrichten für ihn im Zwischenpuffer 16 liegen. Ebenso kann der Protokollprozess 21 durch ein Event „Neue Daten im Zwischenpuffer" von dem Betriebssystemkern 24 aktiviert werden.
• – Der Protokollprozess 21 interpretiert die im Zwischenpuffer 16 liegenden Bytes der Kommando-APDU, um Informationen über die Gesamtlänge der zu empfangenden Nachricht oder Strukturinformationen über die Nachricht zu erhalten, welche zu ihrer weiteren Bearbeitung benötigt werden. Hierbei werden bestimmte Bytes der eingehenden Kommando-APDU ausgewertet, z. B. das Class-Byte CLA, welches gemäß ISO/IEC 7816-4 im Bit 5 anzeigt, ob die aktuell eintreffende Kommando-APDU das letzte/einzige Kommando (CLA Bit 5 = 0) einer Kette von Kommandos ist, oder ob die aktuelle Kommando-APDU nicht das letzte Kommando der Kette ist (CLA Bit 5 = 1) und noch weitere Kommandos folgen. Derartige miteinander verknüpfte Ketten von Kommandos („Command Chaining") sind für einige Kommandotypen, z. B. PUT DATA, die mehr als 255 Bytes an zur Chipkarte zu übertragende Daten umfassen, geeignet. Falls der Protokollprozess 21 daraus schließen kann, dass mehr Teilnachrichten zu erwarten sind, als in den Ringpuffer 16 passen, wird der Speicherprozess 22 entweder von dem Betriebssystemkern 24 oder von dem Protokollprozess 21 veranlasst, den Ringpuffer 16 zu leeren.
• – Ebenso kann der Protokollprozess 21 bei der Interpretation der eintreffenden Daten das INS-Byte, welches einen Rückschluss auf das von der Kommando-APDU übertragene Kommando zulässt, auswerten, um eine Gültigkeitsprüfung der vorliegenden Daten durchzuführen. Ebenso ist es möglich, dass die Interpretation den endgültigen Speicherort der Daten im EEPROM-Speicher 5 der Chipkarte 1 ermittelt, um diese Information dem Speicherprozess 22 per Interprozess-Kommunikation (IPC) mitzuteilen (39).
• – Der Protokollprozess 21 wird nach Erledigung seiner Aufgabe inaktiv und wartet auf die nächste Aktivierung durch den Betriebssystemkern 24 oder die Eingangssteuerung 10 aufgrund im Ringpuffer 16 vorliegender Daten.
• – Nun wird der mit niedriger Priorität ausgeführte Speicherprozess 22 von dem Betriebssystemkern 24 bzw. der Eingangssteuerung 10 aktiviert (37). Ebenso kann der Speicherprozess 22 aktiviert werden, wenn der Ringpuffer 16 einen bestimmten vorgegebenen Füllstand überschritten hat, um diesen rechtzeitig zu leeren, damit weitere eingehende Daten aus dem Eingangspuffer 18 in den Ringpuffer 16 übertragen werden können. Das Überschreiten des Füllstandes kann dann mittels eines Ereignisses (Event) gemeldet werden. Ebenso ist es möglich, dass der Speicherprozess 22 aufgrund eines Ablaufen einer Zeitscheibe oder abhängig von dem Ergebnis einer aktiven Prüfung des Füllstandes des Ringpuffers 16 („Polling") aktiviert wird.
• – Der Speicherprozess 22 liest (40) die in dem Ringpuffer 16 vorliegenden Daten und schreibt (41) diese in den nicht-volatilen Speicherbereich 14. Vorzugsweise kann der Speicherprozess 22 auch warten, bis eine Speicherseite in dem Ringpuffer 16 vollständig vorliegt, d. h. beispielsweise 32 Byte, da ein Speicherzugriff auf den nicht-volatilen Speicher 5 ohnehin zumeist seitenweise erfolgt.
• – Der Speicherprozess 22 kann die Nachricht 16 direkt in einen im EEPROM-Speicher 5 angelegten Zielspeicherbereich des Applikationsprozesses 19, für den die Daten bestimmt sind, aus den Teilnachrichten B1–B8 zusammenfügen. In der Regel existiert jedoch ein spezieller nicht-volatiler Speicherbereich 14, um eine Nachricht dort einerseits aus den empfangenen Teilnachrichten zusammenfügen zu können und andererseits dort eine Vorprüfung der empfangenen Nachricht durchzuführen, z. B. eine kryptographische Sicherheitsoperation oder eine Prüfsummenverifikation. Die Verwendung eines speziellen Speicherbereichs 14 ist insbesondere bei Aktualisierungskommandos sinnvoll (z. B. UPDATE DATA), da ein sofortiges Überschreiben der zu aktualisierenden Daten im Zielspeicherbereich zu einer unerwünschten Dateninkonsistenz führen kann, falls das Aktualisierungskommando unvollständig oder fehlerhaft übertragen wird oder falls eine Verifikation durch einen Prüfsummenvergleich fehlschlägt. Ein unvollständiges oder fehlerhaftes Aktualisierungskommando kann demgegenüber aus einem separaten nicht-volatilen Speicherbereich 14 gelöscht werden, ohne dass die eigentlichen zu aktualisierenden Daten beschädigt werden.
• – In dem nicht-volatilen Speicherbereich 14 fügt der Speicherprozess 22 die vollständige Nachricht B1–B8 so zusammen, dass die Nachricht vorver arbeitet oder im Hinblick auf ihre Gültigkeit oder sicherheitsrelevante Aspekte verifiziert werden kann.
• – Da der Speicherprozess 22 eine niedrigere Priorität als der Unterbrechungsprozess 20 hat, kann er nur zwischen zwei Unterbrechungsphasen, wenn der Unterbrechungsprozess 20 inaktiv ist, aktiviert werden, um aus dem Ringpuffer 16 Teilnachrichten auszulesen. Der Speicherprozess 22 ist also nur für die Zeitdauer der Übertragung von Daten von dem Terminal in den UART-Eingangspuffer 18 aktiv, da er Teilnachrichten nur solange aus dem Zwischenpuffer 16 auslesen kann, wie der Eingangspuffer 18 einen vorgegebenen Füllstand nicht überschreitet. Dann wird wieder der hochprioritäre Unterbrechungsprozess 20 aktiviert.
• – Falls die Nachricht vollständig im nicht-volatilen Speicherbereich 14 vorliegt, was von dem Protokollprozess 22 durch Auswerten des CLA-Bytes ermittelt werden kann, wird abschließend der Applikationsprozess 19 per Interprozesskommunikation (IPC) informiert. Die Aktivierung des Applikationsprozesses 19 kann durch den Speicherprozess 22 selbst, den Betriebssystemkern 24, die Eingangssteuerung 10 oder event-gesteuert erfolgen.
• – Die im nicht-volatilen Speicherbereich 14 nunmehr vollständig vorliegende Nachricht kann auch direkt in den Adressbereich der Applikation 19 kopiert werden, was ein Aufrufen des Kommandointerpreters erforderlich macht, um die Applikation zu ermitteln. Andererseits kann die Applikation aufgefordert werden, auf die Daten ihrerseits zuzugreifen (42).

2 illustrates a method for receiving an overlong message by the in 1 illustrated chip card 1 , At the center of the diagram is the kernel 24 (KERNEL), who also controls the input 10 and / or event control 11 may include. The operating system kern 24 or the reception control 10 Enabled to handle an incoming message synchronizes the interruption process 20 (INTERRUPT PROC) with high priority (PRIORITY = HIGH), the protocol process 21 (PROTOCOL PROC) with medium priority (PRIORITY = MEDIUM) and the storage process 22 (NVM PROC) with low priority (PRIORITY = LOW). Through the synchronized activation and deactivation of these processes 20 . 21 . 22 are received partial messages B1-B8 of an overlong message from the UART input buffer 18 via the RAM ring buffer 16 finally in the non-volatile storage area 14 merged into the complete message and an application process 19 (APP PROC) provided. The procedure of this method is as follows, with parenthesized reference characters characterizing data streams:

• - First, the UART input buffer takes 18 some bits of an incoming message as partial messages on ( 30 ). The incoming partial message is in particular a command APDU ("Application Protocol Data Unit") as the basic communication unit for data transmission from a terminal to a chip card.
• - If there is a partial message in the input buffer 18 and / or when exceeding a predetermined level of the input buffer 18 becomes an interrupt regardless of the operating system kernel 24 an interrupt table which, in the case of the present interruption type "DATA AVAILABLE" ( 31 ) to be executed interrupt handling routine (ISR).
• - Due to the triggered interruption ( 31 ) interrupts the kernel 24 the execution of the momentary of the processor 2 from a guided application process to prioritize the receipt of the message. The DATA AVAILABLE interruption becomes the interrupt process 20 from the kernel 24 activated with the highest execution priority ( 32 ), so that partial messages from the input buffer 18 in the intermediate buffer 16 transmitted as soon as the input buffer 16 exceeds a predetermined level.
• - The interruption process 20 reads a given number or all bits from the UART input buffer 18 out ( 33 ) and write them into the RAM ring buffer 16 ( 34 ). By the synchronization of the processes 20 . 21 and 22 is made sure that the ring buffer 16 never completely filled when in the UART input buffer 18 data to be read, otherwise data loss may occur.
• - The interruption process 20 becomes inactive after completing its task and waits for the next activation due to a break in the input buffer 18 present further sub-messages. The interruption process is just as good 20 also be reactivated when the intermediate buffer 16 is completely emptied, even if the UART input buffer 18 has not yet reached the level required to trigger an interruption. The signaling that the ring buffer 16 is completely emptied, may be triggered by an event or the interruption process 20 by interprocess communication (IPC) from the storage process 22 that's the ring buffer 16 read out, be communicated.
• - Once the high-priority interruption process 16 becomes inactive, becomes the logging process 21 with medium priority from the kernel 24 or the input control 10 activated ( 35 ).
• - The log process 21 , which was possibly already activated immediately after contacting the smart card with the transmitter terminal during an initialization phase of the smart card (the protocol process sends an ATR message ("Answer to Reset") to the terminal with various chip card and Übertra during initialization transmission parameters, z. B. also the size of the ring buffer 16 to detect incoming oversized messages) is now through the kernel 24 activated or continued if it is temporarily inactive. Optionally, it is also possible that the logging process 21 Checks if sub messages for him in the intermediate buffer 16 lie. Likewise, the log process 21 through an event "New data in the intermediate buffer" from the kernel 24 to be activated.
• - The log process 21 interprets them in the intermediate buffer 16 lying bytes of the command APDU to obtain information about the total length of the message to be received or structure information about the message, which are needed for further processing. In this case, certain bytes of the incoming command APDU are evaluated, for. For example, the class byte CLA, which according to ISO / IEC 7816-4 in bit 5 indicates whether the currently arriving command APDU is the last / only command (CLA bit 5 = 0) of a chain of commands, or whether the current one Command APDU is not the last command of the chain (CLA bit 5 = 1) and further commands follow. Such linked chains of commands ("command chaining") are suitable for some types of commands, for example PUT DATA, which comprise more than 255 bytes of data to be transferred to the chip card 21 From this it can be concluded that more sub-messages are to be expected than in the ring buffer 16 fit, becomes the storage process 22 either from the kernel 24 or from the log process 21 causes the ring buffer 16 to empty.
• - Likewise, the log process 21 in the interpretation of the incoming data, evaluate the INS byte, which allows a conclusion on the command transmitted by the command APDU, in order to carry out a validity check of the available data. Likewise, it is possible for the interpretation to be the final location of the data in the EEPROM memory 5 the chip card 1 determines this information to the storage process 22 communicate by interprocess communication (IPC) ( 39 ).
• - The log process 21 will be inactive after completing its task and waiting for the next activation by the kernel 24 or the input control 10 due to the ring buffer 16 available data.
• - Now, the low-priority storage process will be executed 22 from the kernel 24 or the input control 10 activated ( 37 ). Likewise, the storage process 22 be activated when the ring buffer 16 has exceeded a certain predetermined level to empty it in time, so that further incoming data from the input buffer 18 in the ring buffer 16 can be transmitted. Exceeding the level can then be reported by means of an event. Likewise it is possible that the storage process 22 due to expiration of a time slice or depending on the result of an active check of the fill level of the circular buffer 16 ("Polling") is activated.
• - The storage process 22 read ( 40 ) in the ring buffer 16 present data and write ( 41 ) these in the non-volatile storage area 14 , Preferably, the storage process 22 also wait for a memory page in the ring buffer 16 is completely present, ie, for example 32 bytes, as a memory access to the non-volatile memory 5 anyway mostly done page by page.
• - The storage process 22 can the message 16 directly into one in the EEPROM memory 5 created target storage area of the application process 19 for which the data is intended to be composed of the sub-messages B1-B8. In general, however, there is a special non-volatile memory area 14 in order to be able to combine a message there on the one hand from the received submessages and on the other hand to carry out a preliminary check of the received message there, eg. B. a cryptographic security operation or a checksum verification. The use of a special memory area 14 is useful, in particular, for update commands (eg, UPDATE DATA), since an immediate overwriting of the data to be updated in the destination memory area can lead to undesired data inconsistency if the update command is incompletely or incorrectly transmitted or if verification by a checksum comparison fails. In contrast, an incomplete or erroneous update command may consist of a separate non-volatile storage area 14 be deleted without damaging the actual data being updated.
• - In the non-volatile storage area 14 adds the storage process 22 the complete message B1-B8 together so that the message can be pre-processed or verified for validity or security-related aspects.
• - because the storage process 22 a lower priority than the interrupt process 20 has, he can only between two interruption phases when the interruption process 20 is inactive, enabled to get out of the ring buffer 16 Read out part messages. The storage process 22 So it is only for the duration of the transfer of data from the terminal to the UART input buffer 18 active, since it only sub messages from the intermediate buffer 16 can read out how the input buffer 18 does not exceed a predetermined level. Then again the high priority interruption process 20 activated.
• - If the message is completely in the non-volatile storage area 14 what is the protocol process 22 can be determined by evaluating the CLA byte, finally the application process 19 informed by interprocess communication (IPC). The activation of the application process 19 can through the storage process 22 itself, the kernel 24 , the input control 10 or event-controlled.
• - The non-volatile storage area 14 now completely present message can also directly in the address area of the application 19 which calls for calling the command interpreter to determine the application. On the other hand, the application may be requested to access the data for its part ( 42 ).

The method described above has the advantage that the time in which the UART input buffer 18 fills up, from the logging process 21 or the storage process 22 can be exploited, so no dead time (CPU idle time) of the processor 2 when sending and receiving arises.

This in 2 Outlined method is realized by synchronization mechanisms, the speed of data transfer and the internal processor clocking of the smart card 1 are dependent. The minimum remaining time for the storage process 22 In the T = 1 protocol, this results in 11 elementary time units (the duration of one bit in the data transfer to the chip card, depending, inter alia, on the processor clock) minus the respective time expenditure for the process change and the interruption treatment The maximum time remaining for the storage process 22 depends on the CWT ("Character Waiting Time"), which specifies the maximum waiting time between two bytes before data reception is considered terminated.

The above-described method can be used with a memory area 14 in the non-volatile memory 5 be performed. However, since the write times may be limited in a classical EEPROM memory, other non-volatile memory such. As flash memory, or even future storage technologies, such. M-RAM or FeRAM.

The through the in the 1 and 2 Illustrated embodiment enabled receiving over long messages can through the in the 3 and 4 shown further action can be implemented particularly efficiently. In practice, these further technical measures are preferably in the embodiment of the 1 and 2 integ riert, although they are shown and described separately for reasons of clarity.

3 shows a chip card 1 , which is set up to receive overlong messages efficiently. This includes the chip card 1 analogous to that in 1 illustrated chip card 1 a processor 2 (CPU), a communication interface 3 , a UART input buffer 18 and a memory arrangement consisting of a permanent ROM memory 4 , a non-volatile EEPROM memory 5 and a volatile RAM memory 6 ,

In RAM memory 6 is one of the intermediate buffer 16 of the 1 different secondary buffer 17 (SEC.BUFF) to receive partial messages from the UART input buffer 18 arranged. The secondary buffer 17 can be realized differently, for. B. as a selected memory area in a non-volatile memory, for. B. the EEPROM memory 5 or a flash memory, or as the UART input buffer 18 downstream hardware memory chip. The operation of the secondary buffer 17 is determined less by its realization than by its functionality and its size, since it is technically a virtual input buffer in the functional sequence of the operating system 7 is integrated and has a larger data capacity than the actual input buffer 18 , Preferably, the secondary buffer 17 a multiple recording capacity of the input buffer 18 , z. B. five bytes, compared to the usual UART capacity of less than five bytes, usually one byte.

With regard to the embodiment of the 1 When a sub message arrives, the secondary buffer becomes between the UART input buffer 18 and the intermediate buffer 16 arranged so that an incoming partial message from the UART input buffer 18 over the second buffers 17 in the intermediate buffer 16 and finally into the EEPROM memory area 14 arrives.

In the RAM memory 6 there is a reserved memory area 15 (BUFFER), which is intended, during a message reception, the incoming partial messages from the virtual input buffer 17 take. The storage area 15 can in a combined realization of the embodiments of the 1 and 3 the intermediate buffer 16 of the 1 correspond. In this case, the interruption process would 20 not directly to the UART input buffer 18 but partial messages from the secondary buffer 17 read out ( 33 ) and in the memory area 15 or the intermediate buffer 16 write ( 34 ).

The multitasking / multithreading kernel 8th distributes the processor time to different processes / threads in a special user mode 27 (USER MODE) whose accessibility to the hardware is very restricted for security reasons, so that the process can only access operating system routines or hardware drivers via special system calls. In user mode 27 Executed programs and applications therefore do not cause serious system damage or crashes in case of errors. In general, at least application processes 19 (APP-PROC) as well as the protocol process 21 in restricted user mode 27 executed while the operating system kernel 24 , together with z. Device drivers, process control, file system control, interrupt control, etc. in privileged system mode 26 (SYSTEM MODE) is operated.

In ROM memory 4 lies as part of the operating system 7 a secondary buffer control 12 (VIRTUAL FIRMWARE), which is not considered more conventional by the kernel 8th in user mode 27 is implemented as in system mode 26 to be executed virtual firmware of the secondary buffer 17 , The secondary buffer control 12 can also be considered as part of the kernel 8th or as an application in the EEPROM memory 5 will be realized. It is preferably implemented close to the hardware and is located as a control program of the secondary buffer 17 at a relatively low level of abstraction of the operating system 7 , Therefore, the secondary buffer control becomes 12 from the operating system 7 as virtual firmware 12 of a virtual UART input buffer used as a secondary buffer 17 in RAM memory 6 the chip card 1 is realized.

4 illustrates the process sequence and data streams in a method for handling a message entry in a smart card 1 to 3 , At the center of the procedure is the operating system kernel 24 (KERNEL) whose routines are in privileged system mode 26 (SYSTEM MODE). If partial messages of an incoming message in the UART input buffer 18 present ( 30 ), ie when a given level of the UART input buffer 18 exceeded, an interrupt is triggered ( 31 ) to the data input in the UART input buffer 18 to treat with priority.

Contrary to in connection with 2 now described is not the standard interrupt routine (ISR) 20 in restricted user mode 27 activated by a complex process change, but it is the secondary buffer control 12 (SECONDARY BUFFER CONTROL) is activated by means of a corresponding interrupt request (IRQ) ( 32 ). The secondary buffer control 12 becomes a virtual firmware of the secondary buffer due to its specialized realization 17 from the kernel 24 in privileged system mode 26 activated without process change. The execution of the secondary buffer control 12 instead of the traditional interruption process 20 when an interruption occurs ( 31 ) can be realized by the secondary buffer control 12 in an interrupt table with the presence of data in the UART input buffer 18 triggered interrupt is associated as an associated interrupt handling routine (ISR). The secondary buffer control 12 can intervene faster than the interruption process 20 because they have immediate access to the as a secondary buffer 17 equipped area of RAM memory 6 has and in its execution in system mode 26 no complex process change must take place.

The secondary buffer control 12 read ( 33 ) the data from the UART input buffer 18 and writes ( 34 ) put them in the secondary buffer 17 , Because the secondary buffer 17 compared to the UART input buffer 18 preferably has a multiple data capacity, is also a multiple recording volume of the UART input buffer 18 in the virtual input buffer 17 by the efficient activation of the secondary buffer control 12 collected. Only when the secondary buffer 17 exceeds a certain predetermined level, becomes, in its functionality, but not in its realization and activation, with the interruption process 20 of the 1 comparable secondary interruption process 23 (SECONDARY INTERRUPT PROC) in user mode 27 activated by process change. The secondary buffer 17 thus acts as a the actual input buffer 18 downstream virtual input buffer, as a regular treatment of incoming sub-messages through processes in user mode 27 only when it is in the secondary buffer 17 enough data is available.

Exceeding a predetermined level of the secondary buffer 17 is through the event monitoring 11 registered and by means of a secondary interrupt signal ( 43 ) signals. In terms of software, this can be realized as an "event." Conceptually, the secondary interrupt signal ( 43 ) in the present context, however, no conventional event, but acts as a virtual interrupt, by the presence of sub-messages in the virtual input buffer 17 is triggered. Alternatively, event handling can also be done by the kernel 24 or from the secondary buffer control functioning as a virtual firmware 12 of the secondary buffer 17 to be provided.

Subsequently, the secondary interrupt process 23 in user mode 27 started to receive submessages from the secondary buffer 17 to read out ( 44 ) and in the space provided for this purpose 15 (BUFFER) to write ( 45 ). When combining the devices of the 1 and 3 (or the method of 2 and 4 ) transmits ( 33 . 34 ) the secondary interrupt process 23 Partial messages from the secondary buffer 17 in the ring memory 16 where they come from the log and storage process 21 . 22 according to the in 4 illustrated process further processed.

As a result, a time-consuming process change in the in 4 not sketched out at everyone in the UART input buffer 18 incoming byte, but only if the larger secondary buffer 17 is filled. The resulting time gain may be due to the process control of the kernel 8th for processing other application processes 19 be used efficiently, with the expected increase in efficiency of the size of the virtual input buffer 17 is dependent.

Claims (55)

Method for receiving a message by a portable data medium ( 1 ) with a non-volatile memory ( 5 ) and an asynchronous input buffer ( 18 ) that continuously fills with sub-messages, characterized by the steps: - transmitting ( 33 . 34 ) from in the input buffer ( 18 ) present sub messages in an intermediate buffer ( 16 ) of the data carrier ( 1 ); and - save ( 40 . 41 ) in the intermediate buffer ( 16 ) present sub messages in a non-volatile memory ( 5 ) of the data carrier ( 1 ) such that the complete message is assembled from the sub-messages; the steps of transmitting ( 33 . 34 ) and saving ( 40 . 41 ) are synchronized such that partial messages from the intermediate buffer ( 16 ) in the non-volatile memory ( 5 ) as long as the input buffer ( 18 ) does not exceed a predetermined level. Method according to claim 1, characterized in that the steps of transmitting ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) and saving ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ) are synchronized such that partial messages from the input buffer ( 18 ) in the intermediate buffer ( 16 ) are transmitted when the input buffer ( 18 ) exceeds a predetermined level. Method according to claim 1 or 2, characterized in that in the step of transmitting ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) the partial messages into one in a RAM memory ( 6 ) of the data carrier ( 1 ) intermediate buffers ( 16 ), which is larger than the input buffer ( 18 ). Method according to one of claims 1 to 3, characterized in that in the step of storing ( 40 . 41 ) of sub-messages in the non-volatile memory ( 5 ) the message in a separate memory area ( 14 ) of the non-volatile memory ( 5 ) is completely assembled and verified there. Method according to one of claims 1 to 4, characterized in that in the non-volatile memory ( 5 ) assembled message of an application ( 13 . 19 ) for which the message is intended. Method according to one of claims 1 to 5, characterized in that the sub-messages are page by page in the non-volatile memory ( 5 ) get saved. Method according to one of claims 1 to 6, characterized in that partial messages in the non-volatile memory ( 5 ), while the process of transmitting ( 33 . 34 ) emptied input buffers ( 18 ) fills. Method according to one of claims 1 to 7, characterized by the further step of determining ( 38 ) of information in the intermediate buffer ( 16 ), wherein the determined information is a length information about the length of the message and / or a structure information about the structure of the message. A method according to claim 8, characterized in that after the step of determining ( 38 ) of the information in the intermediate buffer ( 16 ) present sub-messages the step of storing ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ), the information determined in the step of storing ( 40 . 41 ) is taken into account. Method according to claim 8 or 9, characterized in that the determining ( 38 ) of information and / or storage ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ) or continues and transmitting ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) is set or interrupted when the intermediate buffer ( 16 ) when transferring ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) exceeds a predetermined maximum level. Method according to one of claims 8 to 10, characterized in that the transferring ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) is initiated or continued and the determination ( 38 ) of information and / or storage ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ) is set or interrupted when the intermediate buffer ( 16 ) falls below a predetermined minimum level and / or if the input buffer ( 18 ) exceeds a predetermined level. Method according to one of claims 8 to 11, characterized in that the steps of transmitting ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) and / or storing ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ) and / or determining ( 38 ) of the information as at least partially concurrent processes from a processor ( 2 ) of the data carrier ( 1 ). Method according to one of claims 1 to 12, characterized in that an interruption ( 31 ) a work of a processor ( 2 ) of the data carrier ( 1 ) is triggered and the transfer ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) is initiated as soon as the input buffer ( 18 ) exceeds a predetermined level. Method according to one of claims 8 to 12 with 13, characterized in that the transmission ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) as a high execution priority process, determining ( 38 ) of information as a process with medium execution priority and storing ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ) as a process with low execution priority on the processor ( 2 ) is executed. A method according to claim 14, characterized in that further from the processor ( 2 ) are executed with lower execution priority than the process of saving ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ). Portable disk ( 1 ), comprising a processor ( 2 ), a non-volatile memory ( 5 ) and an asynchronous input buffer ( 18 ), which fills continuously with partial messages of the message upon receipt of a message, characterized by an intermediate buffer ( 16 ) and one of the processor ( 2 ) executable input control ( 10 ), which is set up, - in the input buffer ( 18 ) present sub messages in the intermediate buffer ( 16 ) transferred to; In the intermediate buffer ( 16 ) in the non-volatile memory ( 5 ) save; and - transmitting ( 33 . 34 ) and saving ( 40 . 41 ) such that partial messages from the intermediate buffer ( 16 ) in the non-volatile memory ( 5 ) as long as the input buffer ( 18 ) does not exceed a predetermined level. Disk ( 1 ) according to claim 16, characterized in that the input control ( 10 ), the transmission ( 33 . 34 ) of sub-messages in the intermediate buffer ( 16 ) and saving ( 40 . 41 ) of the sub-messages in the non-volatile memory ( 5 ) such that partial messages from the input buffer ( 18 ) in the intermediate buffer ( 16 ) are transmitted when the input buffer ( 18 ) exceeds a predetermined level. Disk ( 1 ) according to claim 16 or 17, characterized in that the asynchronous input buffer ( 18 ) is a UART memory device. Disk ( 1 ) according to one of claims 16 to 18, characterized in that the intermediate buffer ( 16 ) in a RAM memory ( 6 ) of the data carrier ( 1 ) arranged memory area, in particular a ring memory. Disk ( 1 ) according to claim 19, characterized in that the intermediate buffer ( 16 ) has a larger storage capacity than the input buffer ( 18 ). Disk ( 1 ) according to one of claims 16 to 20, characterized in that the data carrier ( 1 ) an interruption device ( 9 ), which is set up, an interruption ( 31 ) a work of the processor ( 2 ) when the input buffer ( 18 ) exceeds a predetermined level. Disk ( 1 ) according to claim 21, characterized in that the input control ( 10 ) is set up in the event of an interruption ( 31 ) an execution of an interruption process ( 20 ) for transferring ( 33 . 34 ) from in the input buffer ( 18 ) present partial messages by the processor ( 2 ). Disk ( 1 ) according to one of claims 16 to 22, characterized in that the input control ( 10 ), an execution of a storage process ( 22 ) to save ( 40 . 41 ) in the intermediate buffer ( 16 ) present sub messages in the non-volatile memory ( 5 ) by the processor ( 2 ). Disk ( 1 ) according to claim 23, characterized in that the storage process ( 22 ), the sub-messages are paged in the non-volatile memory ( 5 ) save. Disk ( 1 ) according to claim 23 or 24, characterized in that the storage process ( 22 ), the merged message of an application ( 13 . 19 ) for which the message is intended to be provided. Disk ( 1 ) according to one of claims 23 to 25, characterized in that in the non-volatile memory ( 5 ) a separate memory area ( 14 ) and the storage process ( 22 ), the message in the separate memory area ( 14 ) of the non-volatile memory ( 5 ) from the sub-messages and verify there. Disk ( 1 ) according to one of claims 16 to 26, characterized in that the input control ( 10 ), an execution of a protocol process ( 21 ) by the processor ( 2 ), which extracts information from the intermediate buffer ( 16 ) determined sub-messages, wherein the determined information is a length information about the length of the message and / or a structure information about the structure of the message. Disk ( 1 ) according to one of claims 23 to 26, characterized in that the input control ( 10 ), an execution of the storage process ( 22 ) after the execution of the logging process ( 21 ), and that of the protocol process ( 21 ) determined information from the storage process ( 22 ) is taken into account. Disk ( 1 ) according to claim 28, characterized in that the input control ( 10 ), the execution of the logging process ( 21 ) and / or the storage process ( 22 ) or to continue the execution of the interruption process ( 20 ) to terminate or interrupt when the intermediate buffer ( 16 ) as a result of the transfer ( 33 . 34 ) of the interruption process ( 20 ) exceeds a predetermined maximum level. Disk ( 1 ) according to claim 28 or 29, characterized in that the input control ( 10 ), the execution of the logging process ( 21 ) and / or the storage process ( 22 ) to interrupt or terminate the execution of the interruption process ( 20 ) or to start when the input buffer ( 18 ) exceeds a predetermined level and / or if the intermediate buffer ( 16 ) falls below a predetermined minimum level. Disk ( 1 ) according to one of Claims 16 to 30, characterized by event monitoring ( 11 ) of the data carrier ( 1 ), which is set, exceeding a predetermined maximum level and / or falling below a predetermined minimum level of the intermediate buffer ( 16 ) and the input control ( 10 ) by a level signal. Disk ( 1 ) according to one of claims 16 to 31, characterized in that the data carrier ( 1 ) an operating system ( 7 ), which is set up processes on the processor ( 2 ) run concurrently, and the input control ( 10 ), an at least partially concurrent execution of an interruption process ( 20 ) and / or a protocol process ( 21 ) and / or a storage process ( 22 ). Disk ( 1 ) according to claim 32, characterized in that the input control ( 10 ), the execution of the interruption process ( 20 ) with high execution priority, the execution of the logging process ( 21 ) with medium execution priority, and the execution of the storage process ( 22 ) with lower execution priority. Disk ( 1 ) according to claim 33, characterized in that the operating system ( 7 ), more of the processor ( 2 ) executing processes with lower execution priorities than the storage process ( 22 ). Disk ( 1 ) according to one of claims 16 to 34, characterized in that the input control ( 10 ) Part of an operating system ( 7 ) of the data carrier ( 1 ) and / or an operating system kernel ( 8th ) of the data carrier ( 1 ). Disk ( 1 ) according to one of claims 16 to 35, characterized in that the data carrier ( 1 ) is a smart card, a secure multimedia card, a USB storage medium or a mobile phone card. Method according to one of Claims 1 to 15 for receiving a message by a portable data carrier ( 1 ) with an operating system ( 7 ), which is a system mode ( 26 ) and a user mode limited thereto ( 27 ), characterized by the step of forwarding ( 33 . 34 ) from in the input buffer ( 18 ) present sub messages in a secondary buffer ( 17 ) of the data carrier ( 1 ), which is larger than the input buffer ( 18 ), the step of forwarding ( 33 . 34 ) from the operating system ( 7 ) in the privileged system mode ( 26 ) is carried out. Method according to claim 37, characterized in that an interruption ( 31 ) a work of the processor ( 2 ) and the step of forwarding ( 33 . 34 ) is initiated when the Input buffer ( 18 ) exceeds a predetermined level. A method according to claim 38, characterized in that in response to the interruption ( 31 ) a secondary buffer control ( 12 . 25 ) is activated, which forwarding ( 33 . 34 ) of partial messages from the input buffer ( 18 ) into the secondary buffer ( 17 ) such that no process change by the operating system ( 7 ) must be made. Method according to one of claims 37 to 39, characterized in that a level of the secondary buffer ( 17 ) and a secondary interrupt signal ( 43 ) is triggered when the secondary buffer ( 17 ) exceeds a predetermined level. A method according to claim 40, characterized in that in response to the secondary interrupt signal ( 43 ) a secondary interrupt process ( 23 ), which in the secondary buffer ( 17 ) present partial messages in a memory area ( 15 ) of the data carrier ( 1 ), in particular in the intermediate buffer ( 16 ). A method according to claim 41, characterized in that the secondary interruption process ( 23 ) from the operating system ( 7 ) in the restricted user mode ( 27 ) is performed. Method according to claim 41 or 42, characterized in that for carrying out the secondary interruption process ( 23 ) a process change by the operating system ( 18 ) is made. Method according to one of claims 41 to 43, characterized in that in the memory area ( 15 ) of the data carrier ( 1 ) and / or stored in a destination memory area and / or an application ( 13 . 19 ) to be provided. 45: Method according to one of claims 37 to 44, characterized in that method steps by the processor ( 2 ) in the form of at least partially concurrent operations and / or processes. Portable disk ( 1 ) according to one of claims 16 to 36, an operating system ( 7 ), which is a system mode ( 26 ) and a user mode limited thereto ( 27 ), characterized in that the data carrier ( 1 ) a secondary buffer ( 17 ) that is larger than the input buffer ( 18 ), and one from the processor ( 2 ) in the privileged system mode ( 26 ) executable secondary buffer control ( 12 . 25 ), which is set up, in the input buffer ( 18 ) present sub messages in the secondary buffer ( 17 ) ( 33 . 34 ). Disk ( 1 ) according to claim 46, characterized in that the secondary buffer ( 17 ) as a storage area in a RAM memory ( 6 ) of the data carrier ( 1 ) is realized. Disk ( 1 ) according to claim 46 or 47, characterized in that the secondary buffer control ( 12 . 25 ) than in system mode ( 26 ) operable virtual firmware ( 12 . 25 ) of the secondary buffer ( 17 ) in the operating system ( 7 ) is integrated. Disk ( 1 ) according to one of claims 46 to 48, characterized in that the data carrier ( 1 ) an interruption device ( 9 ), which is set up at the interruption ( 31 ) in system mode ( 26 ) operable secondary buffer control ( 12 . 25 ) as the interruption ( 31 ) to enable an associated interrupt handling routine. Disk ( 1 ) according to claim 49, characterized in that the secondary buffer control ( 12 . 25 ) is set up in the event of an interruption ( 31 ) without a process change by the operating system ( 7 ) to be activated. Disk ( 1 ) according to one of claims 46 to 50, characterized in that the data carrier ( 1 ) an event monitor ( 11 ), which is set up, a level of the secondary buffer ( 17 ) and a secondary interrupt signal ( 43 ), if the secondary buffer ( 17 ) exceeds a predetermined level. Disk ( 1 ) according to claim 51, characterized in that the data carrier ( 1 ) an input control ( 10 ), which is arranged in response to a secondary interrupt signal ( 43 ) an execution of a secondary interrupt process ( 23 ) for transferring ( 44 . 45 ) of in the secondary buffer ( 17 ) present partial messages in a memory area ( 15 ) of the data carrier ( 1 ), in particular in the intermediate buffer ( 16 ). Disk ( 1 ) according to claim 52, characterized in that the operating system ( 18 ), the secondary interrupt process ( 23 ) in the restricted user mode ( 27 ) to operate. Disk ( 1 ) according to claim 52 or 53, characterized in that the input control ( 10 ) is set up in the memory area ( 15 ) to process present sub-messages and / or to copy into a destination memory area and / or an application ( 13 . 19 ). Disk ( 1 ) according to one of claims 46 to 54, characterized in that the operating system ( 7 ), processes on the processor ( 2 ) run concurrently. Disk ( 1 ) according to one of claims 46 to 55, characterized in that the input buffer ( 18 ) can hold less than five bytes, preferably one byte, and the secondary buffer ( 17 ) can hold at least five bytes.