memorybanknv.java

这是一个以JAVA编写的程序,本人还没有试过,是一个简单的温度控制系统

   /**
    * Query to get a string description of what is contained in
    * the Extra Informationed return when reading pages in the current
    * memory bank.  See 'hasExtraInfo()'.
    *
    * @return string describing extra information.
    */
   public String getExtraInfoDescription ()
   {
      return extraInfoDescription;
   }

   //--------
   //-------- MemoryBank I/O methods
   //--------

   /**
    * Read  memory in the current 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().  readPageCRC()
    * however 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 thing is read consistantly.
    *
    * @param  startAddr     starting physical address
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       read() continious where the last one led off
    *                       and it is inside a 'beginExclusive/endExclusive'
    *                       block.
    * @param  readBuf       byte array to place read data into
    * @param  offset        offset into readBuf to place data
    * @param  len           length in bytes to read
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void read (int startAddr, boolean readContinue, byte[] readBuf,
                     int offset, int len)
      throws OneWireIOException, OneWireException
   {
      int i;

      // attempt to put device at max desired speed
      if (!readContinue)
         sp.checkSpeed();

      // check if read exceeds memory
      if ((startAddr + len) > (pageLength * numberPages))
         throw new OneWireException("Read exceeds memory bank end");

      // see if need to access the device
      if (!readContinue)
      {

         // select the device
         if (!ib.adapter.select(ib.address))
         {
            sp.forceVerify();

            throw new OneWireIOException("Device select failed");
         }

         // build start reading memory block
         int    addr    = startAddr + startPhysicalAddress;
         byte[] raw_buf = new byte [3];

         raw_buf [0] = READ_MEMORY_COMMAND;
         raw_buf [1] = ( byte ) (addr & 0xFF);
         raw_buf [2] = ( byte ) (((addr & 0xFFFF) >>> 8) & 0xFF);

         // do the first block for command, address
         ib.adapter.dataBlock(raw_buf, 0, 3);
      }

      // pre-fill readBuf with 0xFF 
      int pgs   = len / pageLength;
      int extra = len % pageLength;

      for (i = 0; i < pgs; i++)
         System.arraycopy(ffBlock, 0, readBuf, offset + i * pageLength,
                          pageLength);
      System.arraycopy(ffBlock, 0, readBuf, offset + pgs * pageLength, extra);

      // send second block to read data, return result
      ib.adapter.dataBlock(readBuf, offset, len);
   }

   /**
    * Write  memory in the current bank.  It is recommended that
    * when writing  data that some structure in the data is created
    * to provide error free reading back with read().  Or the
    * method 'writePagePacket()' could be used which automatically
    * wraps the data in a length and CRC.
    *
    * When using on Write-Once devices care must be taken to write into
    * into empty space.  If write() is used to write over an unlocked
    * page on a Write-Once device it will fail.  If write verification
    * is turned off with the method 'setWriteVerification(false)' then
    * the result will be an 'AND' of the existing data and the new data.
    *
    * @param  startAddr     starting address
    * @param  writeBuf      byte array containing data to write
    * @param  offset        offset into writeBuf to get data
    * @param  len           length in bytes to write
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void write (int startAddr, byte[] writeBuf, int offset, int len)
      throws OneWireIOException, OneWireException
   {
      int i, room_left;

      // return if nothing to do
      if (len == 0)
         return;

      // attempt to put device at speed
      sp.checkSpeed();

      // check if write exceeds memory
      if ((startAddr + len) > size)
         throw new OneWireException("Write exceeds memory bank end");

      // check if trying to write read only bank
      if (isReadOnly())
         throw new OneWireException("Trying to write read-only memory bank");

      // loop while still have pages to write
      int    startx    = 0, nextx = 0;   // (start and next index into writeBuf)
      byte[] raw_buf   = new byte [pageLength];
      byte[] extra_buf = new byte [sp.getExtraInfoLength()];
      int    abs_addr  = startPhysicalAddress + startAddr;
      int    pl        = pageLength;

      do
      {

         // calculate room left in current page
         room_left = pl - ((abs_addr + startx) % pl);

         // check if block left will cross end of page
         if ((len - startx) > room_left)
            nextx = startx + room_left;
         else
            nextx = len;

         // write the page of data to scratchpad
         sp.writeScratchpad(abs_addr + startx, writeBuf, offset + startx,
                            nextx - startx);

         // read to verify ok
         sp.readScratchpad(raw_buf, 0, pl, extra_buf);

         // check to see if the same
         for (i = 0; i < (nextx - startx); i++)
            if (raw_buf [i] != writeBuf [i + offset + startx])
            {
               sp.forceVerify();

               throw new OneWireIOException(
                  "Read back of scratchpad had incorrect data");
            }

         // check to make sure that the address is correct  
         if ((((extra_buf [0] & 0x00FF) | ((extra_buf [1] << 8) & 0x00FF00))
                 & 0x00FFFF) != (abs_addr + startx))
         {
            sp.forceVerify();

            throw new OneWireIOException(
               "Address read back from scrachpad was incorrect");
         }

         // do the copy
         sp.copyScratchpad(abs_addr + startx, nextx - startx);

         // point to next index
         startx = nextx;
      }
      while (nextx < len);
   }

   //--------
   //-------- PagedMemoryBank I/O methods
   //--------

   /**
    * Read  page in the current 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().  readPageCRC() however 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 thing is read consistantly.
    *
    * @param  page          page number to read packet from
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       readPage() continious where the last one
    *                       led off and it is inside a
    *                       'beginExclusive/endExclusive' block.
    * @param  readBuf       byte array to place read data into
    * @param  offset        offset into readBuf to place data
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void readPage (int page, boolean readContinue, byte[] readBuf,
                         int offset)
      throws OneWireIOException, OneWireException
   {
      read(page * pageLength, readContinue, readBuf, offset, pageLength);
   }

   /**
    * Read  page with extra information in the current 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().  readPageCRC() however 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 thing is read consistantly.
    * See the method 'hasExtraInfo()' for a description of the optional
    * extra information some devices have.
    *
    * @param  page          page number to read packet from
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       readPage() continious where the last one
    *                       led off and it is inside a
    *                       'beginExclusive/endExclusive' block.
    * @param  readBuf       byte array to place read data into
    * @param  offset        offset into readBuf to place data
    * @param  extraInfo     byte array to put extra info read into
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void readPage (int page, boolean readContinue, byte[] readBuf,
                         int offset, byte[] extraInfo)
      throws OneWireIOException, OneWireException
   {

      // only needs to be implemented if supported by hardware
      throw new OneWireException(
         "Read page with extra-info not supported by this memory bank");
   }

   /**
    * Read 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.  This is structure is
    * used by this method to verify the data but is not returned, only
    * the data payload is returned.
    *
    * @param  page          page number to read packet from
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       readPagePacket() continious where the last one
    *                       stopped and it is inside a
    *                       'beginExclusive/endExclusive' block.
    * @param  readBuf       byte array to put data read. Must have at least
    *                       'getMaxPacketDataLength()' elements.
    * @param  offset        offset into readBuf to place data
    *
    * @return  number of data bytes read from the device and written to
    *          readBuf at the offset.
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public int readPagePacket (int page, boolean readContinue, byte[] readBuf,
                              int offset)
      throws OneWireIOException, OneWireException
   {
      byte[] raw_buf = new byte [pageLength];

      // read the  page
      readPage(page, readContinue, raw_buf, 0);

      // check if length is realistic
      if ((raw_buf [0] & 0x00FF) > maxPacketDataLength)
         throw new OneWireIOException("Invalid length in packet");

      // verify the CRC is correct
      int abs_page = (startPhysicalAddress / pageLength) + page;
      if (CRC16.compute(raw_buf, 0, raw_buf [0] + 3, abs_page) == 0x0000B001)
      {

         // extract the data out of the packet
         System.arraycopy(raw_buf, 1, readBuf, offset, raw_buf [0]);

         // return the length
         return raw_buf [0];
      }
      else
         throw new OneWireIOException("Invalid CRC16 in packet read");
   }

   /**
    * Read a Universal Data Packet and extra information.  See the
    * method 'readPagePacket()' for a description of the packet structure.
    * See the method 'hasExtraInfo()' for a description of the optional
    * extra information some devices have.
    *
    * @param  page          page number to read packet from
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       readPagePacket() continious where the last one
    *                       stopped and it is inside a
    *                       'beginExclusive/endExclusive' block.
    * @param  readBuf       byte array to put data read. Must have at least
    *                       'getMaxPacketDataLength()' elements.
    * @param  offset        offset into readBuf to place data
    * @param  extraInfo     byte array to put extra info read into
    *
    * @return  number of data bytes read from the device and written to
    *          readBuf at the offset.
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public int readPagePacket (int page, boolean readContinue, byte[] readBuf,
                              int offset, byte[] extraInfo)
      throws OneWireIOException, OneWireException
   {

      // only needs to be implemented if supported by hardware
      throw new OneWireException(
         "Read packet with extra-info not supported by this memory bank");
   }

   /**
    * Write a Universal Data Packet.  See the method 'readPagePacket()'
    * for a description of the packet structure.
    *
    * @param  page          page number to write packet to
    * @param  writeBuf      data byte array to write
    * @param  offset        offset into writeBuf where data to write is
    * @param  len           number of bytes to write
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void writePagePacket (int page, byte[] writeBuf, int offset,
                                int len)
      throws OneWireIOException, OneWireException
   {

      // make sure length does not exceed max
      if (len > maxPacketDataLength)
         throw new OneWireIOException(
            "Length of packet requested exceeds page size");

      // see if this bank is general read/write
      if (!generalPurposeMemory)
         throw new OneWireException(
            "Current bank is not general purpose memory");

      // construct the packet to write
      byte[] raw_buf = new byte [len + 3];

      raw_buf [0] = ( byte ) len;

      System.arraycopy(writeBuf, offset, raw_buf, 1, len);

      int abs_page = (startPhysicalAddress / pageLength) + page;
      int crc = CRC16.compute(raw_buf, 0, len + 1, abs_page);

      raw_buf [len + 1] = ( byte ) (~crc & 0xFF);
      raw_buf [len + 2] = ( byte ) (((~crc & 0xFFFF) >>> 8) & 0xFF);

      // write the packet, return result
      write(page * pageLength, raw_buf, 0, len + 3);
   }

   /**
    * Read a complete memory page with CRC verification provided by the
    * device.  Not supported by all devices.  See the method
    * 'hasPageAutoCRC()'.
    *
    * @param  page          page number to read
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       readPagePacket() continious where the last one
    *                       stopped and it is inside a
    *                       'beginExclusive/endExclusive' block.
    * @param  readBuf       byte array to put data read. Must have at least
    *                       'getMaxPacketDataLength()' elements.
    * @param  offset        offset into readBuf to place data
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void readPageCRC (int page, boolean readContinue, byte[] readBuf,
                            int offset)
      throws OneWireIOException, OneWireException
   {

      // only needs to be implemented if supported by hardware
      throw new OneWireException(
         "Read page with CRC not supported by this memory bank");
   }

   /**
    * Read a complete memory page with CRC verification provided by the
    * device with extra information.  Not supported by all devices.
    * See the method 'hasPageAutoCRC()'.
    * See the method 'hasExtraInfo()' for a description of the optional
    * extra information.
    *
    * @param  page          page number to read
    * @param  readContinue  if 'true' then device read is continued without
    *                       re-selecting.  This can only be used if the new
    *                       readPagePacket() continious where the last one
    *                       stopped and it is inside a
    *                       'beginExclusive/endExclusive' block.
    * @param  readBuf       byte array to put data read. Must have at least
    *                       'getMaxPacketDataLength()' elements.
    * @param  offset        offset into readBuf to place data
    * @param  extraInfo     byte array to put extra info read into
    *
    * @throws OneWireIOException
    * @throws OneWireException
    */
   public void readPageCRC (int page, boolean readContinue, byte[] readBuf,
                            int offset, byte[] extraInfo)
      throws OneWireIOException, OneWireException
   {

      // only needs to be implemented if supported by hardware
      throw new OneWireException(
         "Read page with CRC and extra-info not supported by this memory bank");
   }
}