Dataflash_WaitWhileBusy() now always ensures that the dataflash is ready for the next command immediately after returning, no need to call Dataflash_ToggleSelectedChipCS() afterwards.

Added new DATAFLASH_CHIP_MASK() macro to the Dataflash driver, which returns the Dataflash select mask for the given chip index.

Updated MassStorage device block write routines to use ping-pong Dataflash buffering to increase throughput by around 30%.

1 files changed, 29 insertions, 20 deletions

diff --git a/Demos/Device/ClassDriver/MassStorage/Lib/DataflashManager.c b/Demos/Device/ClassDriver/MassStorage/Lib/DataflashManager.c
index 326f66024..2335a5e8f 100644
--- a/Demos/Device/ClassDriver/MassStorage/Lib/DataflashManager.c
+++ b/Demos/Device/ClassDriver/MassStorage/Lib/DataflashManager.c
@@ -43,7 +43,6 @@
  *  the pre-selected data OUT endpoint. This routine reads in OS sized blocks from the endpoint and writes

  *  them to the dataflash in Dataflash page sized blocks.

  *

- *  \param[in] MSInterfaceInfo  Pointer to a Mass Storage class state structure for the Mass Storage interface being used

  *  \param[in] BlockAddress  Data block starting address for the write sequence

  *  \param[in] TotalBlocks   Number of blocks of data to write

  */

@@ -52,11 +51,14 @@ void DataflashManager_WriteBlocks(USB_ClassInfo_MS_Device_t* MSInterfaceInfo, co
 	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);

+	bool     UsingSecondBuffer   = false;

 

 	/* Copy selected dataflash's current page contents to the dataflash buffer */

 	Dataflash_SelectChipFromPage(CurrDFPage);

+#if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE)

 	Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1);

 	Dataflash_SendAddressBytes(CurrDFPage, 0);

+#endif

 	Dataflash_WaitWhileBusy();

 

 	/* Send the dataflash buffer write command */

@@ -88,34 +90,36 @@ void DataflashManager_WriteBlocks(USB_ClassInfo_MS_Device_t* MSInterfaceInfo, co
 			if (CurrDFPageByteDiv16 == (DATAFLASH_PAGE_SIZE >> 4))

 			{

 				/* Write the dataflash buffer contents back to the dataflash page */

-				Dataflash_ToggleSelectedChipCS();

-				Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);

+				Dataflash_WaitWhileBusy();

+				Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE : DF_CMD_BUFF1TOMAINMEMWITHERASE);

 				Dataflash_SendAddressBytes(CurrDFPage, 0);

 

 				/* Reset the dataflash buffer counter, increment the page counter */

 				CurrDFPageByteDiv16 = 0;

 				CurrDFPage++;

 

+				/* Once all the dataflash ICs have had their first buffers filled, switch buffers to maintain throughput */

+				if (Dataflash_GetSelectedChip() == DATAFLASH_CHIP_MASK(DATAFLASH_TOTALCHIPS))

+				  UsingSecondBuffer = !(UsingSecondBuffer);

+

 				/* 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_WaitWhileBusy();

+					Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_MAINMEMTOBUFF2 : 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);

+				Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2WRITE : DF_CMD_BUFF1WRITE);

+				Dataflash_SendAddressBytes(0, 0);				

 			}

 

 			/* Write one 16-byte chunk of data to the dataflash */

@@ -152,8 +156,8 @@ void DataflashManager_WriteBlocks(USB_ClassInfo_MS_Device_t* MSInterfaceInfo, co
 	}

 

 	/* Write the dataflash buffer contents back to the dataflash page */

-	Dataflash_ToggleSelectedChipCS();

-	Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);

+	Dataflash_WaitWhileBusy();

+	Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE : DF_CMD_BUFF1TOMAINMEMWITHERASE);

 	Dataflash_SendAddressBytes(CurrDFPage, 0x00);

 	Dataflash_WaitWhileBusy();

 

@@ -169,7 +173,6 @@ void DataflashManager_WriteBlocks(USB_ClassInfo_MS_Device_t* MSInterfaceInfo, co
  *  the pre-selected data IN endpoint. This routine reads in Dataflash page sized blocks from the Dataflash

  *  and writes them in OS sized blocks to the endpoint.

  *

- *  \param[in] MSInterfaceInfo  Pointer to a Mass Storage class state structure for the Mass Storage interface being used

  *  \param[in] BlockAddress  Data block starting address for the read sequence

  *  \param[in] TotalBlocks   Number of blocks of data to read

  */

@@ -282,11 +285,14 @@ void DataflashManager_WriteBlocks_RAM(const uint32_t BlockAddress, uint16_t Tota
 	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);

+	bool     UsingSecondBuffer   = false;

 

 	/* Copy selected dataflash's current page contents to the dataflash buffer */

 	Dataflash_SelectChipFromPage(CurrDFPage);

+#if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE)

 	Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1);

 	Dataflash_SendAddressBytes(CurrDFPage, 0);

+#endif

 	Dataflash_WaitWhileBusy();

 

 	/* Send the dataflash buffer write command */

@@ -305,25 +311,28 @@ void DataflashManager_WriteBlocks_RAM(const uint32_t BlockAddress, uint16_t Tota
 			if (CurrDFPageByteDiv16 == (DATAFLASH_PAGE_SIZE >> 4))

 			{

 				/* Write the dataflash buffer contents back to the dataflash page */

-				Dataflash_ToggleSelectedChipCS();

-				Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);

+				Dataflash_WaitWhileBusy();

+				Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE : DF_CMD_BUFF1TOMAINMEMWITHERASE);

 				Dataflash_SendAddressBytes(CurrDFPage, 0);

 

 				/* Reset the dataflash buffer counter, increment the page counter */

 				CurrDFPageByteDiv16 = 0;

 				CurrDFPage++;

 

+				/* Once all the dataflash ICs have had their first buffers filled, switch buffers to maintain throughput */

+				if (Dataflash_GetSelectedChip() == DATAFLASH_CHIP_MASK(DATAFLASH_TOTALCHIPS))

+				  UsingSecondBuffer = !(UsingSecondBuffer);

+

 				/* 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_WaitWhileBusy();

+					Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_MAINMEMTOBUFF2 : DF_CMD_MAINMEMTOBUFF1);

 					Dataflash_SendAddressBytes(CurrDFPage, 0);

 					Dataflash_WaitWhileBusy();

 				}

@@ -351,8 +360,8 @@ void DataflashManager_WriteBlocks_RAM(const uint32_t BlockAddress, uint16_t Tota
 	}

 

 	/* Write the dataflash buffer contents back to the dataflash page */

-	Dataflash_ToggleSelectedChipCS();

-	Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);

+	Dataflash_WaitWhileBusy();

+	Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE : DF_CMD_BUFF1TOMAINMEMWITHERASE);

 	Dataflash_SendAddressBytes(CurrDFPage, 0x00);

 	Dataflash_WaitWhileBusy();

 

@@ -367,7 +376,7 @@ void DataflashManager_WriteBlocks_RAM(const uint32_t BlockAddress, uint16_t Tota
  *

  *  \param[in] BlockAddress  Data block starting address for the read sequence

  *  \param[in] TotalBlocks   Number of blocks of data to read

- *  \param[out] BufferPtr     Pointer to the data destination RAM buffer

+ *  \param[out] BufferPtr    Pointer to the data destination RAM buffer

  */

 void DataflashManager_ReadBlocks_RAM(const uint32_t BlockAddress, uint16_t TotalBlocks, uint8_t* BufferPtr)

 {