aboutsummaryrefslogtreecommitdiffstats
path: root/Demos/Device/LowLevel/MassStorage/Lib/DataflashManager.c
blob: ebd1b39c3fd0e22bbb0637477833b8316e4627fe (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
/*
             LUFA Library
     Copyright (C) Dean Camera, 2017.

  dean [at] fourwalledcubicle [dot] com
           www.lufa-lib.org
*/

/*
  Copyright 2017  Dean Camera (dean [at] fourwalledcubicle [dot] com)

  Permission to use, copy, modify, distribute, and sell this
  software and its documentation for any purpose is hereby granted
  without fee, provided that the above copyright notice appear in
  all copies and that both that the copyright notice and this
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
  software without specific, written prior permission.

  The author disclaims all warranties with regard to this
  software, including all implied warranties of merchantability
  and fitness.  In no event shall the author be liable for any
  special, indirect or consequential damages or any damages
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

/** \file
 *
 *  Functions to manage the physical Dataflash media, including reading and writing of
 *  blocks of data. These functions are called by the SCSI layer when data must be stored
 *  or retrieved to/from the physical storage media. If a different media is used (such
 *  as a SD card or EEPROM), functions similar to these will need to be generated.
 */

#define  INCLUDE_FROM_DATAFLASHMANAGER_C
#include "DataflashManager.h"

/** Writes blocks (OS blocks, not Dataflash pages) to the storage medium, the board Dataflash IC(s), from
 *  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] BlockAddress  Data block starting address for the write sequence
 *  \param[in] TotalBlocks   Number of blocks of data to write
 */
void DataflashManager_WriteBlocks(const uint32_t BlockAddress,
                                  uint16_t TotalBlocks)
{
	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;

	/* Select the correct starting Dataflash IC for the block requested */
	Dataflash_SelectChipFromPage(CurrDFPage);

#if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE)
	/* Copy selected dataflash's current page contents to the Dataflash buffer */
	Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1);
	Dataflash_SendAddressBytes(CurrDFPage, 0);
	Dataflash_WaitWhileBusy();
#endif

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

	/* Wait until endpoint is ready before continuing */
	if (Endpoint_WaitUntilReady())
	  return;

	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 the endpoint is currently empty */
			if (!(Endpoint_IsReadWriteAllowed()))
			{
				/* Clear the current endpoint bank */
				Endpoint_ClearOUT();

				/* Wait until the host has sent another packet */
				if (Endpoint_WaitUntilReady())
				  return;
			}

			/* Check if end of Dataflash page reached */
			if (CurrDFPageByteDiv16 == (DATAFLASH_PAGE_SIZE >> 4))
			{
				/* Write the Dataflash buffer contents back to the Dataflash page */
				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);

#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_WaitWhileBusy();
					Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_MAINMEMTOBUFF2 : DF_CMD_MAINMEMTOBUFF1);
					Dataflash_SendAddressBytes(CurrDFPage, 0);
					Dataflash_WaitWhileBusy();
				}
#endif

				/* Send the Dataflash buffer write command */
				Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2WRITE : DF_CMD_BUFF1WRITE);
				Dataflash_SendAddressBytes(0, 0);
			}

			/* Write one 16-byte chunk of data to the Dataflash */
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());
			Dataflash_SendByte(Endpoint_Read_8());

			/* 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--;
	}

	/* Write the Dataflash buffer contents back to the Dataflash page */
	Dataflash_WaitWhileBusy();
	Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE : DF_CMD_BUFF1TOMAINMEMWITHERASE);
	Dataflash_SendAddressBytes(CurrDFPage, 0x00);
	Dataflash_WaitWhileBusy();

	/* If the endpoint is empty, clear it ready for the next packet from the host */
	if (!(Endpoint_IsReadWriteAllowed()))
	  Endpoint_ClearOUT();

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

/** Reads blocks (OS blocks, not Dataflash pages) from the storage medium, the board Dataflash IC(s), into
 *  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] BlockAddress  Data block starting address for the read sequence
 *  \param[in] TotalBlocks   Number of blocks of data to read
 */
void DataflashManager_ReadBlocks(const uint32_t BlockAddress,
                                 uint16_t TotalBlocks)
{
	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);

	/* Select the correct starting Dataflash IC for the block requested */
	Dataflash_SelectChipFromPage(CurrDFPage);

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

	/* Wait until endpoint is ready before continuing */
	if (Endpoint_WaitUntilReady())
	  return;

	while (TotalBlocks)
	{
		uint8_t BytesInBlockDiv16 = 0;

		/* Read an endpoint packet sized data block from the Dataflash */
		while (BytesInBlockDiv16 < (VIRTUAL_MEMORY_BLOCK_SIZE >> 4))
		{
			/* Check if the endpoint is currently full */
			if (!(Endpoint_IsReadWriteAllowed()))
			{
				/* Clear the endpoint bank to send its contents to the host */
				Endpoint_ClearIN();

				/* Wait until the endpoint is ready for more data */
				if (Endpoint_WaitUntilReady())
				  return;
			}

			/* 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 */
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(Dataflash_ReceiveByte());
			Endpoint_Write_8(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 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[in] BlockAddress  Data block starting address for the write sequence
 *  \param[in] TotalBlocks   Number of blocks of data to write
 *  \param[in] 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);
	bool     UsingSecondBuffer   = false;

	/* Select the correct starting Dataflash IC for the block requested */
	Dataflash_SelectChipFromPage(CurrDFPage);

#if (DATAFLASH_PAGE_SIZE > VIRTUAL_MEMORY_BLOCK_SIZE)
	/* Copy selected dataflash's current page contents to the Dataflash buffer */
	Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF1);
	Dataflash_SendAddressBytes(CurrDFPage, 0);
	Dataflash_WaitWhileBusy();
#endif

	/* Send the Dataflash buffer write command */
	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_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);

#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_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(UsingSecondBuffer ? DF_CMD_BUFF2WRITE : 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++;
		}

		/* Decrement the blocks remaining counter */
		TotalBlocks--;
	}

	/* Write the Dataflash buffer contents back to the Dataflash page */
	Dataflash_WaitWhileBusy();
	Dataflash_SendByte(UsingSecondBuffer ? DF_CMD_BUFF2TOMAINMEMWITHERASE : 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 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[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
 */
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);

	/* Select the correct starting Dataflash IC for the block requested */
	Dataflash_SelectChipFromPage(CurrDFPage);

	/* Send the Dataflash main memory page read command */
	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;

		/* Read an endpoint packet sized data block from 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++;
		}

		/* 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();
}

/** Performs a simple test on the attached Dataflash IC(s) to ensure that they are working.
 *
 *  \return Boolean \c true if all media chips are working, \c false otherwise
 */
bool DataflashManager_CheckDataflashOperation(void)
{
	uint8_t ReturnByte;

	/* Test first Dataflash IC is present and responding to commands */
	Dataflash_SelectChip(DATAFLASH_CHIP1);
	Dataflash_SendByte(DF_CMD_READMANUFACTURERDEVICEINFO);
	ReturnByte = Dataflash_ReceiveByte();
	Dataflash_DeselectChip();

	/* If returned data is invalid, fail the command */
	if (ReturnByte != DF_MANUFACTURER_ATMEL)
	  return false;

	#if (DATAFLASH_TOTALCHIPS == 2)
	/* Test second Dataflash IC is present and responding to commands */
	Dataflash_SelectChip(DATAFLASH_CHIP2);
	Dataflash_SendByte(DF_CMD_READMANUFACTURERDEVICEINFO);
	ReturnByte = Dataflash_ReceiveByte();
	Dataflash_DeselectChip();

	/* If returned data is invalid, fail the command */
	if (ReturnByte != DF_MANUFACTURER_ATMEL)
	  return false;
	#endif

	return true;
}