3      Copyright (C) Dean Camera, 2009. 
   5   dean [at] fourwalledcubicle [dot] com 
   6       www.fourwalledcubicle.com 
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com) 
  12   Permission to use, copy, modify, and distribute this software 
  13   and its documentation for any purpose and without fee is hereby 
  14   granted, provided that the above copyright notice appear in all 
  15   copies and that both that the copyright notice and this 
  16   permission notice and warranty disclaimer appear in supporting 
  17   documentation, and that the name of the author not be used in 
  18   advertising or publicity pertaining to distribution of the 
  19   software without specific, written prior permission. 
  21   The author disclaim all warranties with regard to this 
  22   software, including all implied warranties of merchantability 
  23   and fitness.  In no event shall the author be liable for any 
  24   special, indirect or consequential damages or any damages 
  25   whatsoever resulting from loss of use, data or profits, whether 
  26   in an action of contract, negligence or other tortious action, 
  27   arising out of or in connection with the use or performance of 
  33  *  Functions to manage the physical dataflash media, including reading and writing of 
  34  *  blocks of data. These functions are called by the SCSI layer when data must be stored 
  35  *  or retrieved to/from the physical storage media. If a different media is used (such 
  36  *  as a SD card or EEPROM), functions similar to these will need to be generated. 
  39 #define  INCLUDE_FROM_DATAFLASHMANAGER_C 
  40 #include "DataflashManager.h" 
  42 /** Writes blocks (OS blocks, not Dataflash pages) to the storage medium, the board dataflash IC(s), from 
  43  *  the pre-selected data OUT endpoint. This routine reads in OS sized blocks from the endpoint and writes 
  44  *  them to the dataflash in Dataflash page sized blocks. 
  46  *  \param[in] BlockAddress  Data block starting address for the write sequence 
  47  *  \param[in] TotalBlocks   Number of blocks of data to write 
  49 void DataflashManager_WriteBlocks(const uint32_t BlockAddress
, uint16_t TotalBlocks
) 
  51         uint16_t CurrDFPage          
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) / DATAFLASH_PAGE_SIZE
); 
  52         uint16_t CurrDFPageByte      
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) % DATAFLASH_PAGE_SIZE
); 
  53         uint8_t  CurrDFPageByteDiv16 
= (CurrDFPageByte 
>> 4); 
  54         bool     UsingSecondBuffer   
= false; 
  56         /* Select the correct starting Dataflash IC for the block requested */ 
  57         Dataflash_SelectChipFromPage(CurrDFPage
); 
  59 #if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE) 
  60         /* Copy selected dataflash's current page contents to the dataflash buffer */ 
  61         Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1
); 
  62         Dataflash_SendAddressBytes(CurrDFPage
, 0); 
  63         Dataflash_WaitWhileBusy(); 
  66         /* Send the dataflash buffer write command */ 
  67         Dataflash_SendByte(DF_CMD_BUFF1WRITE
); 
  68         Dataflash_SendAddressBytes(0, CurrDFPageByte
); 
  70         /* Wait until endpoint is ready before continuing */ 
  71         if (Endpoint_WaitUntilReady()) 
  76                 uint8_t BytesInBlockDiv16 
= 0; 
  78                 /* Write an endpoint packet sized data block to the dataflash */ 
  79                 while (BytesInBlockDiv16 
< (VIRTUAL_MEMORY_BLOCK_SIZE 
>> 4)) 
  81                         /* Check if the endpoint is currently empty */ 
  82                         if (!(Endpoint_IsReadWriteAllowed())) 
  84                                 /* Clear the current endpoint bank */ 
  87                                 /* Wait until the host has sent another packet */ 
  88                                 if (Endpoint_WaitUntilReady()) 
  92                         /* Check if end of dataflash page reached */ 
  93                         if (CurrDFPageByteDiv16 
== (DATAFLASH_PAGE_SIZE 
>> 4)) 
  95                                 /* Write the dataflash buffer contents back to the dataflash page */ 
  96                                 Dataflash_WaitWhileBusy(); 
  97                                 Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE 
: DF_CMD_BUFF1TOMAINMEMWITHERASE
); 
  98                                 Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 100                                 /* Reset the dataflash buffer counter, increment the page counter */ 
 101                                 CurrDFPageByteDiv16 
= 0; 
 104                                 /* Once all the dataflash ICs have had their first buffers filled, switch buffers to maintain throughput */ 
 105                                 if (Dataflash_GetSelectedChip() == DATAFLASH_CHIP_MASK(DATAFLASH_TOTALCHIPS
)) 
 106                                   UsingSecondBuffer 
= !(UsingSecondBuffer
); 
 108                                 /* Select the next dataflash chip based on the new dataflash page index */ 
 109                                 Dataflash_SelectChipFromPage(CurrDFPage
); 
 111 #if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE) 
 112                                 /* If less than one dataflash page remaining, copy over the existing page to preserve trailing data */ 
 113                                 if ((TotalBlocks 
* (VIRTUAL_MEMORY_BLOCK_SIZE 
>> 4)) < (DATAFLASH_PAGE_SIZE 
>> 4)) 
 115                                         /* Copy selected dataflash's current page contents to the dataflash buffer */ 
 116                                         Dataflash_WaitWhileBusy(); 
 117                                         Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_MAINMEMTOBUFF2 
: DF_CMD_MAINMEMTOBUFF1
); 
 118                                         Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 119                                         Dataflash_WaitWhileBusy(); 
 123                                 /* Send the dataflash buffer write command */ 
 124                                 Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2WRITE 
: DF_CMD_BUFF1WRITE
); 
 125                                 Dataflash_SendAddressBytes(0, 0);                                
 128                         /* Write one 16-byte chunk of data to the dataflash */ 
 129                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 130                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 131                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 132                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 133                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 134                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 135                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 136                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 137                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 138                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 139                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 140                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 141                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 142                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 143                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 144                         Dataflash_SendByte(Endpoint_Read_Byte()); 
 146                         /* Increment the dataflash page 16 byte block counter */ 
 147                         CurrDFPageByteDiv16
++; 
 149                         /* Increment the block 16 byte block counter */ 
 152                         /* Check if the current command is being aborted by the host */ 
 153                         if (IsMassStoreReset
) 
 157                 /* Decrement the blocks remaining counter and reset the sub block counter */ 
 161         /* Write the dataflash buffer contents back to the dataflash page */ 
 162         Dataflash_WaitWhileBusy(); 
 163         Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE 
: DF_CMD_BUFF1TOMAINMEMWITHERASE
); 
 164         Dataflash_SendAddressBytes(CurrDFPage
, 0x00); 
 165         Dataflash_WaitWhileBusy(); 
 167         /* If the endpoint is empty, clear it ready for the next packet from the host */ 
 168         if (!(Endpoint_IsReadWriteAllowed())) 
 171         /* Deselect all dataflash chips */ 
 172         Dataflash_DeselectChip(); 
 175 /** Reads blocks (OS blocks, not Dataflash pages) from the storage medium, the board dataflash IC(s), into 
 176  *  the pre-selected data IN endpoint. This routine reads in Dataflash page sized blocks from the Dataflash 
 177  *  and writes them in OS sized blocks to the endpoint. 
 179  *  \param[in] BlockAddress  Data block starting address for the read sequence 
 180  *  \param[in] TotalBlocks   Number of blocks of data to read 
 182 void DataflashManager_ReadBlocks(const uint32_t BlockAddress
, uint16_t TotalBlocks
) 
 184         uint16_t CurrDFPage          
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) / DATAFLASH_PAGE_SIZE
); 
 185         uint16_t CurrDFPageByte      
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) % DATAFLASH_PAGE_SIZE
); 
 186         uint8_t  CurrDFPageByteDiv16 
= (CurrDFPageByte 
>> 4); 
 188         /* Select the correct starting Dataflash IC for the block requested */ 
 189         Dataflash_SelectChipFromPage(CurrDFPage
); 
 191         /* Send the dataflash main memory page read command */ 
 192         Dataflash_SendByte(DF_CMD_MAINMEMPAGEREAD
); 
 193         Dataflash_SendAddressBytes(CurrDFPage
, CurrDFPageByte
); 
 194         Dataflash_SendByte(0x00); 
 195         Dataflash_SendByte(0x00); 
 196         Dataflash_SendByte(0x00); 
 197         Dataflash_SendByte(0x00); 
 199         /* Wait until endpoint is ready before continuing */ 
 200         if (Endpoint_WaitUntilReady()) 
 205                 uint8_t BytesInBlockDiv16 
= 0; 
 207                 /* Write an endpoint packet sized data block to the dataflash */ 
 208                 while (BytesInBlockDiv16 
< (VIRTUAL_MEMORY_BLOCK_SIZE 
>> 4)) 
 210                         /* Check if the endpoint is currently full */ 
 211                         if (!(Endpoint_IsReadWriteAllowed())) 
 213                                 /* Clear the endpoint bank to send its contents to the host */ 
 216                                 /* Wait until the endpoint is ready for more data */ 
 217                                 if (Endpoint_WaitUntilReady()) 
 221                         /* Check if end of dataflash page reached */ 
 222                         if (CurrDFPageByteDiv16 
== (DATAFLASH_PAGE_SIZE 
>> 4)) 
 224                                 /* Reset the dataflash buffer counter, increment the page counter */ 
 225                                 CurrDFPageByteDiv16 
= 0; 
 228                                 /* Select the next dataflash chip based on the new dataflash page index */ 
 229                                 Dataflash_SelectChipFromPage(CurrDFPage
); 
 231                                 /* Send the dataflash main memory page read command */ 
 232                                 Dataflash_SendByte(DF_CMD_MAINMEMPAGEREAD
); 
 233                                 Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 234                                 Dataflash_SendByte(0x00); 
 235                                 Dataflash_SendByte(0x00); 
 236                                 Dataflash_SendByte(0x00); 
 237                                 Dataflash_SendByte(0x00); 
 240                         /* Read one 16-byte chunk of data from the dataflash */ 
 241                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 242                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 243                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 244                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 245                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 246                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 247                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 248                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 249                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 250                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 251                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 252                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 253                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 254                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 255                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 256                         Endpoint_Write_Byte(Dataflash_ReceiveByte()); 
 258                         /* Increment the dataflash page 16 byte block counter */ 
 259                         CurrDFPageByteDiv16
++; 
 261                         /* Increment the block 16 byte block counter */ 
 264                         /* Check if the current command is being aborted by the host */ 
 265                         if (IsMassStoreReset
) 
 269                 /* Decrement the blocks remaining counter */ 
 273         /* If the endpoint is full, send its contents to the host */ 
 274         if (!(Endpoint_IsReadWriteAllowed())) 
 277         /* Deselect all dataflash chips */ 
 278         Dataflash_DeselectChip(); 
 281 /** Writes blocks (OS blocks, not Dataflash pages) to the storage medium, the board dataflash IC(s), from 
 282  *  the a given RAM buffer. This routine reads in OS sized blocks from the buffer and writes them to the 
 283  *  dataflash in Dataflash page sized blocks. This can be linked to FAT libraries to write files to the 
 286  *  \param[in] BlockAddress  Data block starting address for the write sequence 
 287  *  \param[in] TotalBlocks   Number of blocks of data to write 
 288  *  \param[in] BufferPtr     Pointer to the data source RAM buffer 
 290 void DataflashManager_WriteBlocks_RAM(const uint32_t BlockAddress
, uint16_t TotalBlocks
, uint8_t* BufferPtr
) 
 292         uint16_t CurrDFPage          
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) / DATAFLASH_PAGE_SIZE
); 
 293         uint16_t CurrDFPageByte      
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) % DATAFLASH_PAGE_SIZE
); 
 294         uint8_t  CurrDFPageByteDiv16 
= (CurrDFPageByte 
>> 4); 
 295         bool     UsingSecondBuffer   
= false; 
 297         /* Select the correct starting Dataflash IC for the block requested */ 
 298         Dataflash_SelectChipFromPage(CurrDFPage
); 
 300 #if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE) 
 301         /* Copy selected dataflash's current page contents to the dataflash buffer */ 
 302         Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1
); 
 303         Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 304         Dataflash_WaitWhileBusy(); 
 307         /* Send the dataflash buffer write command */ 
 308         Dataflash_SendByte(DF_CMD_BUFF1WRITE
); 
 309         Dataflash_SendAddressBytes(0, CurrDFPageByte
); 
 313                 uint8_t BytesInBlockDiv16 
= 0; 
 315                 /* Write an endpoint packet sized data block to the dataflash */ 
 316                 while (BytesInBlockDiv16 
< (VIRTUAL_MEMORY_BLOCK_SIZE 
>> 4)) 
 318                         /* Check if end of dataflash page reached */ 
 319                         if (CurrDFPageByteDiv16 
== (DATAFLASH_PAGE_SIZE 
>> 4)) 
 321                                 /* Write the dataflash buffer contents back to the dataflash page */ 
 322                                 Dataflash_WaitWhileBusy(); 
 323                                 Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE 
: DF_CMD_BUFF1TOMAINMEMWITHERASE
); 
 324                                 Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 326                                 /* Reset the dataflash buffer counter, increment the page counter */ 
 327                                 CurrDFPageByteDiv16 
= 0; 
 330                                 /* Once all the dataflash ICs have had their first buffers filled, switch buffers to maintain throughput */ 
 331                                 if (Dataflash_GetSelectedChip() == DATAFLASH_CHIP_MASK(DATAFLASH_TOTALCHIPS
)) 
 332                                   UsingSecondBuffer 
= !(UsingSecondBuffer
); 
 334                                 /* Select the next dataflash chip based on the new dataflash page index */ 
 335                                 Dataflash_SelectChipFromPage(CurrDFPage
); 
 337 #if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE) 
 338                                 /* If less than one dataflash page remaining, copy over the existing page to preserve trailing data */ 
 339                                 if ((TotalBlocks 
* (VIRTUAL_MEMORY_BLOCK_SIZE 
>> 4)) < (DATAFLASH_PAGE_SIZE 
>> 4)) 
 341                                         /* Copy selected dataflash's current page contents to the dataflash buffer */ 
 342                                         Dataflash_WaitWhileBusy(); 
 343                                         Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_MAINMEMTOBUFF2 
: DF_CMD_MAINMEMTOBUFF1
); 
 344                                         Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 345                                         Dataflash_WaitWhileBusy(); 
 349                                 /* Send the dataflash buffer write command */ 
 350                                 Dataflash_ToggleSelectedChipCS(); 
 351                                 Dataflash_SendByte(DF_CMD_BUFF1WRITE
); 
 352                                 Dataflash_SendAddressBytes(0, 0); 
 355                         /* Write one 16-byte chunk of data to the dataflash */ 
 356                         for (uint8_t ByteNum 
= 0; ByteNum 
< 16; ByteNum
++) 
 357                           Dataflash_SendByte(*(BufferPtr
++)); 
 359                         /* Increment the dataflash page 16 byte block counter */ 
 360                         CurrDFPageByteDiv16
++; 
 362                         /* Increment the block 16 byte block counter */ 
 366                 /* Decrement the blocks remaining counter and reset the sub block counter */ 
 370         /* Write the dataflash buffer contents back to the dataflash page */ 
 371         Dataflash_WaitWhileBusy(); 
 372         Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE 
: DF_CMD_BUFF1TOMAINMEMWITHERASE
); 
 373         Dataflash_SendAddressBytes(CurrDFPage
, 0x00); 
 374         Dataflash_WaitWhileBusy(); 
 376         /* Deselect all dataflash chips */ 
 377         Dataflash_DeselectChip(); 
 380 /** Reads blocks (OS blocks, not Dataflash pages) from the storage medium, the board dataflash IC(s), into 
 381  *  the a preallocated RAM buffer. This routine reads in Dataflash page sized blocks from the Dataflash 
 382  *  and writes them in OS sized blocks to the given buffer. This can be linked to FAT libraries to read 
 383  *  the files stored on the dataflash. 
 385  *  \param[in] BlockAddress  Data block starting address for the read sequence 
 386  *  \param[in] TotalBlocks   Number of blocks of data to read 
 387  *  \param[out] BufferPtr    Pointer to the data destination RAM buffer 
 389 void DataflashManager_ReadBlocks_RAM(const uint32_t BlockAddress
, uint16_t TotalBlocks
, uint8_t* BufferPtr
) 
 391         uint16_t CurrDFPage          
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) / DATAFLASH_PAGE_SIZE
); 
 392         uint16_t CurrDFPageByte      
= ((BlockAddress 
* VIRTUAL_MEMORY_BLOCK_SIZE
) % DATAFLASH_PAGE_SIZE
); 
 393         uint8_t  CurrDFPageByteDiv16 
= (CurrDFPageByte 
>> 4); 
 395         /* Select the correct starting Dataflash IC for the block requested */ 
 396         Dataflash_SelectChipFromPage(CurrDFPage
); 
 398         /* Send the dataflash main memory page read command */ 
 399         Dataflash_SendByte(DF_CMD_MAINMEMPAGEREAD
); 
 400         Dataflash_SendAddressBytes(CurrDFPage
, CurrDFPageByte
); 
 401         Dataflash_SendByte(0x00); 
 402         Dataflash_SendByte(0x00); 
 403         Dataflash_SendByte(0x00); 
 404         Dataflash_SendByte(0x00); 
 408                 uint8_t BytesInBlockDiv16 
= 0; 
 410                 /* Write an endpoint packet sized data block to the dataflash */ 
 411                 while (BytesInBlockDiv16 
< (VIRTUAL_MEMORY_BLOCK_SIZE 
>> 4)) 
 413                         /* Check if end of dataflash page reached */ 
 414                         if (CurrDFPageByteDiv16 
== (DATAFLASH_PAGE_SIZE 
>> 4)) 
 416                                 /* Reset the dataflash buffer counter, increment the page counter */ 
 417                                 CurrDFPageByteDiv16 
= 0; 
 420                                 /* Select the next dataflash chip based on the new dataflash page index */ 
 421                                 Dataflash_SelectChipFromPage(CurrDFPage
); 
 423                                 /* Send the dataflash main memory page read command */ 
 424                                 Dataflash_SendByte(DF_CMD_MAINMEMPAGEREAD
); 
 425                                 Dataflash_SendAddressBytes(CurrDFPage
, 0); 
 426                                 Dataflash_SendByte(0x00); 
 427                                 Dataflash_SendByte(0x00); 
 428                                 Dataflash_SendByte(0x00); 
 429                                 Dataflash_SendByte(0x00); 
 432                         /* Read one 16-byte chunk of data from the dataflash */ 
 433                         for (uint8_t ByteNum 
= 0; ByteNum 
< 16; ByteNum
++) 
 434                           *(BufferPtr
++) = Dataflash_ReceiveByte(); 
 436                         /* Increment the dataflash page 16 byte block counter */ 
 437                         CurrDFPageByteDiv16
++; 
 439                         /* Increment the block 16 byte block counter */ 
 443                 /* Decrement the blocks remaining counter */ 
 447         /* Deselect all dataflash chips */ 
 448         Dataflash_DeselectChip(); 
 451 /** Disables the dataflash memory write protection bits on the board Dataflash ICs, if enabled. */ 
 452 void DataflashManager_ResetDataflashProtections(void) 
 454         /* Select first dataflash chip, send the read status register command */ 
 455         Dataflash_SelectChip(DATAFLASH_CHIP1
); 
 456         Dataflash_SendByte(DF_CMD_GETSTATUS
); 
 458         /* Check if sector protection is enabled */ 
 459         if (Dataflash_ReceiveByte() & DF_STATUS_SECTORPROTECTION_ON
) 
 461                 Dataflash_ToggleSelectedChipCS(); 
 463                 /* Send the commands to disable sector protection */ 
 464                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[0]); 
 465                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[1]); 
 466                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[2]); 
 467                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[3]); 
 470         /* Select second dataflash chip (if present on selected board), send read status register command */ 
 471         #if (DATAFLASH_TOTALCHIPS == 2) 
 472         Dataflash_SelectChip(DATAFLASH_CHIP2
); 
 473         Dataflash_SendByte(DF_CMD_GETSTATUS
); 
 475         /* Check if sector protection is enabled */ 
 476         if (Dataflash_ReceiveByte() & DF_STATUS_SECTORPROTECTION_ON
) 
 478                 Dataflash_ToggleSelectedChipCS(); 
 480                 /* Send the commands to disable sector protection */ 
 481                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[0]); 
 482                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[1]); 
 483                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[2]); 
 484                 Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF
[3]); 
 488         /* Deselect current dataflash chip */ 
 489         Dataflash_DeselectChip();