Package com.dalsemi.onewire.container

Interface PagedMemoryBank

All Superinterfaces:
MemoryBank
All Known Subinterfaces:
OTPMemoryBank
All Known Implementing Classes:
MemoryBankNVCRCPW, MemoryBankScratchCRCPW, MemoryBankScratchSHAEE, MemoryBankSHAEE
public interface PagedMemoryBank extends MemoryBank

Paged Memory bank interface for iButtons (or 1-Wire devices) with page based memory. This interface extents the base functionality of the super-interface MemoryBank by providing paged based services.

This interface has methods to read and write a packet structure called the UDP (Universal Data Packet). This structure has a length byte, data, and an inverted CRC16. See Maxim Integrated Products Application Note 114 for details: http://dbserv.maxim-ic.com/appnotes.cfm?appnote_number=114

The MemoryBank methods can be organized into the following categories:

Usage

Example 1

Display some features of PagedMemoryBank instance 'pmb': 
  
  System.out.print("PagedMemoryBank has: " + pmb.getNumberPages() + " pages of length ");
  System.out.print(pbank.getPageLength() + " bytes ");
  if (bank.isGeneralPurposeMemory())
    System.out.print("giving " + pbank.getMaxPacketDataLength() + " bytes Packet data payload");
  System.out.println();

  if (pbank.hasPageAutoCRC())
    System.out.print("PagedMemoryBank has device generated CRC");

Example 2

Write a packet into the first page of a PagedMemoryBank instance 'pmb': 
  
  byte[] write_buf = new byte[pmb.getMaxPacketDataLength()];
  for (int i = 0; i < write_buf.length; i++)
      write_buf[i] = (byte)0;

  mb.writePagePacket(0, write_buf, 0, write_buf.length);

Example 3

Read all of the pages of a PagedMemoryBank instance 'pmb' with device CRC verification: 
  
  byte[] read_buf = new byte[pmb.getPageLength()];

  if (pmb.hasAutoCRC())
  {
     // loop to read each page with CRC
     for (int pg = 0; pg < pmb.getNumberPages(); pg++)
     {
        // use 'readContinue' argument to only access device on first page
        pmb.readPageCRC(pg, (pg == 0), read_buf, 0);

        // do something with data in read_buf ...
     }
  }
  else
     System.out.println("PagedMemoryBank does not support device generated CRC");
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    getExtraInfoDescription()
    Gets a string description of what is contained in the Extra Information returned when reading pages in this memory bank.
    int
    getExtraInfoLength()
    Gets the length in bytes of extra information that is read when reading a page in this memory bank.
    int
    getMaxPacketDataLength()
    Gets Maximum data page length in bytes for a packet read or written in this memory bank.
    int
    getNumberPages()
    Gets the number of pages in this memory bank.
    int
    getPageLength()
    Gets raw page length in bytes in this memory bank.
    boolean
    hasExtraInfo()
    Checks to see if this memory bank's pages deliver extra information outside of the normal data space, when read.
    boolean
    hasPageAutoCRC()
    Checks to see if this memory bank's pages can be read with the contents being verified by a device generated CRC.
    void
    readPage(int page, boolean readContinue, byte[] readBuf, int offset)
    Reads a page in this memory bank with no CRC checking (device or data).
    void
    readPage(int page, boolean readContinue, byte[] readBuf, int offset, byte[] extraInfo)
    Reads a page in this memory bank with extra information with no CRC checking (device or data).
    void
    readPageCRC(int page, boolean readContinue, byte[] readBuf, int offset)
    Reads a complete memory page with CRC verification provided by the device.
    void
    readPageCRC(int page, boolean readContinue, byte[] readBuf, int offset, byte[] extraInfo)
    Reads a complete memory page with CRC verification provided by the device with extra information.
    int
    readPagePacket(int page, boolean readContinue, byte[] readBuf, int offset)
    Reads a Universal Data Packet.
    int
    readPagePacket(int page, boolean readContinue, byte[] readBuf, int offset, byte[] extraInfo)
    Reads a Universal Data Packet and extra information.
    void
    writePagePacket(int page, byte[] writeBuf, int offset, int len)
    Writes a Universal Data Packet.

    Methods inherited from interface com.dalsemi.onewire.container.MemoryBank

    getBankDescription, getSize, getStartPhysicalAddress, isGeneralPurposeMemory, isNonVolatile, isReadOnly, isReadWrite, isWriteOnce, needsPowerDelivery, needsProgramPulse, read, setWriteVerification, write

  • Method Details

    • getNumberPages

      int getNumberPages()
      Gets the number of pages in this memory bank. The page numbers are then always 0 to (getNumberPages() - 1).
      Returns:
      number of pages in this memory bank

    • getPageLength

      int getPageLength()
      Gets raw page length in bytes in this memory bank.
      Returns:
      page length in bytes in this memory bank

    • getMaxPacketDataLength

      int getMaxPacketDataLength()
      Gets Maximum data page length in bytes for a packet read or written in this memory bank. See the readPagePacket and writePagePacket methods. This method is only useful if this memory bank is general purpose memory.
      Returns:
      max packet page length in bytes in this memory bank
      See Also:

    • hasPageAutoCRC

      boolean hasPageAutoCRC()
      Checks to see if this memory bank's pages can be read with the contents being verified by a device generated CRC. This is used to see if the readPageCRC method can be used.
      Returns:
      true if this memory bank can be read with self generated CRC
      See Also:

    • hasExtraInfo

      boolean hasExtraInfo()
      Checks to see if this memory bank's pages deliver extra information outside of the normal data space, when read. Examples of this may be a redirection byte, counter, tamper protection bytes, or SHA-1 result. If this method returns true then the methods with an 'extraInfo' parameter can be used: readPage, readPageCRC, and readPagePacket.
      Returns:
      true if reading the this memory bank's pages provides extra information
      Since:
      1-Wire API 0.01
      See Also:

    • getExtraInfoLength

      int getExtraInfoLength()
      Gets the length in bytes of extra information that is read when reading a page in this memory bank.
      Returns:
      number of bytes in Extra Information read when reading pages from this memory bank
      See Also:

    • getExtraInfoDescription

      String getExtraInfoDescription()
      Gets a string description of what is contained in the Extra Information returned when reading pages in this memory bank.
      Returns:
      extra information description.
      See Also:

    • readPage

      void readPage(int page, boolean readContinue, byte[] readBuf, int offset) throws OneWireIOException, OneWireException
      Reads a page in this memory bank with no CRC checking (device or data). The resulting data from this API may or may not be what is on the 1-Wire device. It is recommends that the data contain some kind of checking (CRC) like in the readPagePacket method or have the 1-Wire device provide the CRC as in readPageCRC. However device CRC generation is not supported on all memory types, see hasPageAutoCRC. If neither is an option then this method could be called more then once to at least verify that the same data is read consistently. The readContinue parameter is used to eliminate the overhead in re-accessing a part already being read from. For example, if pages 0 - 4 are to be read, readContinue would be set to false for page 0 and would be set to true for the next four calls.

      Note: Using readContinue = true can only be used if the new read continues where the last one left off and it is inside a 'beginExclusive/endExclusive' block.

      Parameters:
      page - page number to read packet from
      readContinue - true then device read is continued without re-selecting
      readBuf - location for data read
      offset - offset into readBuf to place data
      Throws:
      OneWireIOException - on a 1-Wire communication error such as no 1-Wire device present. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.
      OneWireException - on a communication or setup error with the 1-Wire adapter

    • readPage

      void readPage(int page, boolean readContinue, byte[] readBuf, int offset, byte[] extraInfo) throws OneWireIOException, OneWireException
      Reads a page in this memory bank with extra information with no CRC checking (device or data). The resulting data from this API may or may not be what is on the 1-Wire device. It is recommends that the data contain some kind of checking (CRC) like in the readPagePacket method or have the 1-Wire device provide the CRC as in readPageCRC. However device CRC generation is not supported on all memory types, see hasPageAutoCRC. If neither is an option then this method could be called more then once to at least verify that the same data is read consistently.The readContinue parameter is used to eliminate the overhead in re-accessing a part already being read from. For example, if pages 0 - 4 are to be read, readContinue would be set to false for page 0 and would be set to true for the next four calls.

      Note: Using readContinue = true can only be used if the new read continues where the last one left off and it is inside a 'beginExclusive/endExclusive' block.

      Parameters:
      page - page number to read packet from
      readContinue - true then device read is continued without re-selecting
      readBuf - location for data read
      offset - offset into readBuf to place data
      extraInfo - location for extra info read
      Throws:
      OneWireIOException - on a 1-Wire communication error such as no 1-Wire device present. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.
      OneWireException - on a communication or setup error with the 1-Wire adapter
      See Also:

    • readPagePacket

      int readPagePacket(int page, boolean readContinue, byte[] readBuf, int offset) throws OneWireIOException, OneWireException
      Reads a Universal Data Packet. The Universal Data Packet always starts on page boundaries but can end anywhere in the page. The structure specifies the length of data bytes not including the length byte and the CRC16 bytes. There is one length byte. The CRC16 is first initialized to the page number. This provides a check to verify the page that was intended is being read. The CRC16 is then calculated over the length and data bytes. The CRC16 is then inverted and stored low byte first followed by the high byte. The structure is used by this method to verify the data but only the data payload is returned. The readContinue parameter is used to eliminate the overhead in re-accessing a part already being read from. For example, if pages 0 - 4 are to be read, readContinue would be set to false for page 0 and would be set to true for the next four calls.

      See Maxim Integrated Products Application Note 114 for details: http://dbserv.maxim-ic.com/appnotes.cfm?appnote_number=114

      Note: Using readContinue = true can only be used if the new read continues where the last one left off and it is inside a 'beginExclusive/endExclusive' block.

      Parameters:
      page - page number to read packet from
      readContinue - true true then device read is continued without re-selecting
      readBuf - location for data read
      offset - offset into readBuf to place data
      Returns:
      number of data bytes read from the device and saved to readBuf at the provided offset
      Throws:
      OneWireIOException - on a 1-Wire communication error such as an invalid CRC16 or length found in the packet. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'. It could also be caused due to the device page not containing a valid packet.
      OneWireException - on a communication or setup error with the 1-Wire adapter
      See Also:

    • readPagePacket

      int readPagePacket(int page, boolean readContinue, byte[] readBuf, int offset, byte[] extraInfo) throws OneWireIOException, OneWireException
      Reads a Universal Data Packet and extra information. See the method readPagePacket for a description of the packet structure. The readContinue parameter is used to eliminate the overhead in re-accessing a part already being read from. For example, if pages 0 - 4 are to be read, readContinue would be set to false for page 0 and would be set to true for the next four calls.

      Note: Using readContinue = true can only be used if the new read continues where the last one left off and it is inside a 'beginExclusive/endExclusive' block.

      Parameters:
      page - page number to read packet from
      readContinue - true then device read is continued without re-selecting
      readBuf - location for data read
      offset - offset into readBuf to place data
      extraInfo - location for extra info read
      Returns:
      number of data bytes read from the device and written to readBuf at the offset.
      Throws:
      OneWireIOException - on a 1-Wire communication error such as an invalid CRC16 or length found in the packet. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'. It could also be caused due to the device page not containing a valid packet.
      OneWireException - on a communication or setup error with the 1-Wire adapter
      See Also:

    • writePagePacket

      void writePagePacket(int page, byte[] writeBuf, int offset, int len) throws OneWireIOException, OneWireException
      Writes a Universal Data Packet. See the method readPagePacket for a description of the packet structure.
      Parameters:
      page - page number to write packet to
      writeBuf - data to write
      offset - offset into writeBuf where data to write is
      len - number of bytes to write with a max of getMaxPacketDataLength elements
      Throws:
      OneWireIOException - on a 1-Wire communication error such as read verification error on write. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'. It could also be caused due to the device page being write protected.
      OneWireException - on a communication or setup error with the 1-Wire adapter
      See Also:

    • readPageCRC

      void readPageCRC(int page, boolean readContinue, byte[] readBuf, int offset) throws OneWireIOException, OneWireException
      Reads a complete memory page with CRC verification provided by the device. Not supported by all devices. The readContinue parameter is used to eliminate the overhead in re-accessing a part already being read from. For example, if pages 0 - 4 are to be read, readContinue would be set to false for page 0 and would be set to true for the next four calls.

      Note: Using readContinue = true can only be used if the new read continues where the last one left off and it is inside a 'beginExclusive/endExclusive' block.

      Parameters:
      page - page number to read
      readContinue - true true then device read is continued without re-selecting
      readBuf - location for data read
      offset - offset into readBuf to place data
      Throws:
      OneWireIOException - on a 1-Wire communication error such as an invalid CRC read from device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.
      OneWireException - on a communication or setup error with the 1-Wire adapter
      See Also:

    • readPageCRC

      void readPageCRC(int page, boolean readContinue, byte[] readBuf, int offset, byte[] extraInfo) throws OneWireIOException, OneWireException
      Reads a complete memory page with CRC verification provided by the device with extra information. Not supported by all devices. The readContinue parameter is used to eliminate the overhead in re-accessing a part already being read from. For example, if pages 0 - 4 are to be read, readContinue would be set to false for page 0 and would be set to true for the next four calls.

      Note: Using readContinue = true can only be used if the new read continues where the last one left off and it is inside a 'beginExclusive/endExclusive' block.

      Parameters:
      page - page number to read
      readContinue - true true then device read is issued without continued without re-selecting
      readBuf - location for data read
      offset - offset into readBuf to place data
      extraInfo - location for extra info read
      Throws:
      OneWireIOException - on a 1-Wire communication error such as an invalid CRC read from device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.
      OneWireException - on a communication or setup error with the 1-Wire adapter
      See Also: