dataflashmanager.c

LUFA (Lightweight USB Framework for AVRs) is my first foray into the world of USB. Originally based

			Endpoint_Write_Byte(Dataflash_ReceiveByte());
			Endpoint_Write_Byte(Dataflash_ReceiveByte());
			Endpoint_Write_Byte(Dataflash_ReceiveByte());
			Endpoint_Write_Byte(Dataflash_ReceiveByte());
			Endpoint_Write_Byte(Dataflash_ReceiveByte());
			
			/* Increment the dataflash page 16 byte block counter */
			CurrDFPageByteDiv16++;
			
			/* Increment the block 16 byte block counter */
			BytesInBlockDiv16++;

			/* Check if the current command is being aborted by the host */
			if (IsMassStoreReset)
			  return;
		}
		
		/* Decrement the blocks remaining counter */
		TotalBlocks--;
	}
	
	/* If the endpoint is full, send its contents to the host */
	if (!(Endpoint_IsReadWriteAllowed()))
	  Endpoint_ClearIN();

	/* Deselect all dataflash chips */
	Dataflash_DeselectChip();
}

/** Writes blocks (OS blocks, not Dataflash pages) to the storage medium, the board dataflash IC(s), from
 *  the a given RAM buffer. This routine reads in OS sized blocks from the buffer and writes them to the
 *  dataflash in Dataflash page sized blocks. This can be linked to FAT libraries to write files to the
 *  dataflash.
 *
 *  \param BlockAddress  Data block starting address for the write sequence
 *  \param TotalBlocks   Number of blocks of data to write
 *  \param BufferPtr     Pointer to the data source RAM buffer
 */
void DataflashManager_WriteBlocks_RAM(const uint32_t BlockAddress, uint16_t TotalBlocks, uint8_t* BufferPtr)
{
	uint16_t CurrDFPage          = ((BlockAddress * VIRTUAL_MEMORY_BLOCK_SIZE) / DATAFLASH_PAGE_SIZE);
	uint16_t CurrDFPageByte      = ((BlockAddress * VIRTUAL_MEMORY_BLOCK_SIZE) % DATAFLASH_PAGE_SIZE);
	uint8_t  CurrDFPageByteDiv16 = (CurrDFPageByte >> 4);

	/* Copy selected dataflash's current page contents to the dataflash buffer */
	Dataflash_SelectChipFromPage(CurrDFPage);
	Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1);
	Dataflash_SendAddressBytes(CurrDFPage, 0);
	Dataflash_WaitWhileBusy();

	/* Send the dataflash buffer write command */
	Dataflash_ToggleSelectedChipCS();
	Dataflash_SendByte(DF_CMD_BUFF1WRITE);
	Dataflash_SendAddressBytes(0, CurrDFPageByte);

	while (TotalBlocks)
	{
		uint8_t BytesInBlockDiv16 = 0;
		
		/* Write an endpoint packet sized data block to the dataflash */
		while (BytesInBlockDiv16 < (VIRTUAL_MEMORY_BLOCK_SIZE >> 4))
		{
			/* Check if end of dataflash page reached */
			if (CurrDFPageByteDiv16 == (DATAFLASH_PAGE_SIZE >> 4))
			{
				/* Write the dataflash buffer contents back to the dataflash page */
				Dataflash_ToggleSelectedChipCS();
				Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);
				Dataflash_SendAddressBytes(CurrDFPage, 0);

				/* Reset the dataflash buffer counter, increment the page counter */
				CurrDFPageByteDiv16 = 0;
				CurrDFPage++;

				/* Select the next dataflash chip based on the new dataflash page index */
				Dataflash_SelectChipFromPage(CurrDFPage);
				Dataflash_WaitWhileBusy();

#if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE)
				/* If less than one dataflash page remaining, copy over the existing page to preserve trailing data */
				if ((TotalBlocks * (VIRTUAL_MEMORY_BLOCK_SIZE >> 4)) < (DATAFLASH_PAGE_SIZE >> 4))
				{
					/* Copy selected dataflash's current page contents to the dataflash buffer */
					Dataflash_ToggleSelectedChipCS();
					Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1);
					Dataflash_SendAddressBytes(CurrDFPage, 0);
					Dataflash_WaitWhileBusy();
				}
#endif

				/* Send the dataflash buffer write command */
				Dataflash_ToggleSelectedChipCS();
				Dataflash_SendByte(DF_CMD_BUFF1WRITE);
				Dataflash_SendAddressBytes(0, 0);
			}
			
			/* Write one 16-byte chunk of data to the dataflash */
			for (uint8_t ByteNum = 0; ByteNum < 16; ByteNum++)
			  Dataflash_SendByte(*(BufferPtr++));
			
			/* Increment the dataflash page 16 byte block counter */
			CurrDFPageByteDiv16++;

			/* Increment the block 16 byte block counter */
			BytesInBlockDiv16++;

			/* Check if the current command is being aborted by the host */
			if (IsMassStoreReset)
			  return;			
		}
			
		/* Decrement the blocks remaining counter and reset the sub block counter */
		TotalBlocks--;
	}

	/* Write the dataflash buffer contents back to the dataflash page */
	Dataflash_ToggleSelectedChipCS();
	Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);
	Dataflash_SendAddressBytes(CurrDFPage, 0x00);
	Dataflash_WaitWhileBusy();

	/* Deselect all dataflash chips */
	Dataflash_DeselectChip();
}

/** Reads blocks (OS blocks, not Dataflash pages) from the storage medium, the board dataflash IC(s), into
 *  the a preallocated RAM buffer. This routine reads in Dataflash page sized blocks from the Dataflash
 *  and writes them in OS sized blocks to the given buffer. This can be linked to FAT libraries to read
 *  the files stored on the dataflash.
 *
 *  \param BlockAddress  Data block starting address for the read sequence
 *  \param TotalBlocks   Number of blocks of data to read
 *  \param BufferPtr     Pointer to the data destination RAM buffer
 */
void DataflashManager_ReadBlocks_RAM(const uint32_t BlockAddress, uint16_t TotalBlocks, uint8_t* BufferPtr)
{
	uint16_t CurrDFPage          = ((BlockAddress * VIRTUAL_MEMORY_BLOCK_SIZE) / DATAFLASH_PAGE_SIZE);
	uint16_t CurrDFPageByte      = ((BlockAddress * VIRTUAL_MEMORY_BLOCK_SIZE) % DATAFLASH_PAGE_SIZE);
	uint8_t  CurrDFPageByteDiv16 = (CurrDFPageByte >> 4);

	/* Send the dataflash main memory page read command */
	Dataflash_SelectChipFromPage(CurrDFPage);
	Dataflash_SendByte(DF_CMD_MAINMEMPAGEREAD);
	Dataflash_SendAddressBytes(CurrDFPage, CurrDFPageByte);
	Dataflash_SendByte(0x00);
	Dataflash_SendByte(0x00);
	Dataflash_SendByte(0x00);
	Dataflash_SendByte(0x00);

	while (TotalBlocks)
	{
		uint8_t BytesInBlockDiv16 = 0;
		
		/* Write an endpoint packet sized data block to the dataflash */
		while (BytesInBlockDiv16 < (VIRTUAL_MEMORY_BLOCK_SIZE >> 4))
		{
			/* Check if end of dataflash page reached */
			if (CurrDFPageByteDiv16 == (DATAFLASH_PAGE_SIZE >> 4))
			{
				/* Reset the dataflash buffer counter, increment the page counter */
				CurrDFPageByteDiv16 = 0;
				CurrDFPage++;

				/* Select the next dataflash chip based on the new dataflash page index */
				Dataflash_SelectChipFromPage(CurrDFPage);
				
				/* Send the dataflash main memory page read command */
				Dataflash_SendByte(DF_CMD_MAINMEMPAGEREAD);
				Dataflash_SendAddressBytes(CurrDFPage, 0);
				Dataflash_SendByte(0x00);
				Dataflash_SendByte(0x00);
				Dataflash_SendByte(0x00);
				Dataflash_SendByte(0x00);
			}	

			/* Read one 16-byte chunk of data from the dataflash */
			for (uint8_t ByteNum = 0; ByteNum < 16; ByteNum++)
			  *(BufferPtr++) = Dataflash_ReceiveByte();
			
			/* Increment the dataflash page 16 byte block counter */
			CurrDFPageByteDiv16++;
			
			/* Increment the block 16 byte block counter */
			BytesInBlockDiv16++;

			/* Check if the current command is being aborted by the host */
			if (IsMassStoreReset)
			  return;
		}
		
		/* Decrement the blocks remaining counter */
		TotalBlocks--;
	}

	/* Deselect all dataflash chips */
	Dataflash_DeselectChip();
}

/** Disables the dataflash memory write protection bits on the board Dataflash ICs, if enabled. */
void DataflashManager_ResetDataflashProtections(void)
{
	/* Select first dataflash chip, send the read status register command */
	Dataflash_SelectChip(DATAFLASH_CHIP1);
	Dataflash_SendByte(DF_CMD_GETSTATUS);
	
	/* Check if sector protection is enabled */
	if (Dataflash_ReceiveByte() & DF_STATUS_SECTORPROTECTION_ON)
	{
		Dataflash_ToggleSelectedChipCS();

		/* Send the commands to disable sector protection */
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[0]);
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[1]);
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[2]);
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[3]);
	}
	
	/* Select second dataflash chip (if present on selected board), send read status register command */
	#if (DATAFLASH_TOTALCHIPS == 2)
	Dataflash_SelectChip(DATAFLASH_CHIP2);
	Dataflash_SendByte(DF_CMD_GETSTATUS);
	
	/* Check if sector protection is enabled */
	if (Dataflash_ReceiveByte() & DF_STATUS_SECTORPROTECTION_ON)
	{
		Dataflash_ToggleSelectedChipCS();

		/* Send the commands to disable sector protection */
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[0]);
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[1]);
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[2]);
		Dataflash_SendByte(DF_CMD_SECTORPROTECTIONOFF[3]);
	}
	#endif
	
	/* Deselect current dataflash chip */
	Dataflash_DeselectChip();
}