Projects/AVRISP-MKII/Lib/ISP/ISPProtocol.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all 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.
  20
  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
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  ISP Protocol handler, to process V2 Protocol wrapped ISP commands used in Atmel programmer devices.
  34  */
  35
  36 #include "ISPProtocol.h"
  37
  38 #if defined(ENABLE_ISP_PROTOCOL) || defined(__DOXYGEN__)
  39
  40 /** Handler for the CMD_ENTER_PROGMODE_ISP command, which attempts to enter programming mode on
  41  *  the attached device, returning success or failure back to the host.
  42  */
  43 void ISPProtocol_EnterISPMode(void)
  44 {
  45         struct
  46         {
  47                 uint8_t TimeoutMS;
  48                 uint8_t PinStabDelayMS;
  49                 uint8_t ExecutionDelayMS;
  50                 uint8_t SynchLoops;
  51                 uint8_t ByteDelay;
  52                 uint8_t PollValue;
  53                 uint8_t PollIndex;
  54                 uint8_t EnterProgBytes[4];
  55         } Enter_ISP_Params;
  56
  57         Endpoint_Read_Stream_LE(&Enter_ISP_Params, sizeof(Enter_ISP_Params), NO_STREAM_CALLBACK);
  58
  59         Endpoint_ClearOUT();
  60         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
  61         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
  62
  63         uint8_t ResponseStatus = STATUS_CMD_FAILED;
  64
  65         CurrentAddress = 0;
  66
  67         /* Set up the synchronous USART to generate the recovery clock on XCK pin */
  68         UBRR1  = (F_CPU / 500000UL);
  69         UCSR1B = (1 << TXEN1);
  70         UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
  71         DDRD  |= (1 << 5);
  72
  73         /* Perform execution delay, initialize SPI bus */
  74         ISPProtocol_DelayMS(Enter_ISP_Params.ExecutionDelayMS);
  75         SPI_Init(ISPTarget_GetSPIPrescalerMask() | SPI_SCK_LEAD_RISING | SPI_SAMPLE_LEADING | SPI_MODE_MASTER);
  76
  77         /* Continuously attempt to synchronize with the target until either the number of attempts specified
  78          * by the host has exceeded, or the the device sends back the expected response values */
  79         while (Enter_ISP_Params.SynchLoops-- && (ResponseStatus == STATUS_CMD_FAILED) && TimeoutMSRemaining)
  80         {
  81                 uint8_t ResponseBytes[4];
  82
  83                 ISPTarget_ChangeTargetResetLine(true);
  84                 ISPProtocol_DelayMS(Enter_ISP_Params.PinStabDelayMS);
  85
  86                 for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)
  87                 {
  88                         ISPProtocol_DelayMS(Enter_ISP_Params.ByteDelay);
  89                         ResponseBytes[RByte] = SPI_TransferByte(Enter_ISP_Params.EnterProgBytes[RByte]);
  90                 }
  91
  92                 /* Check if polling disabled, or if the polled value matches the expected value */
  93                 if (!(Enter_ISP_Params.PollIndex) || (ResponseBytes[Enter_ISP_Params.PollIndex - 1] == Enter_ISP_Params.PollValue))
  94                 {
  95                         ResponseStatus = STATUS_CMD_OK;
  96                 }
  97                 else
  98                 {
  99                         ISPTarget_ChangeTargetResetLine(false);
 100                         ISPProtocol_DelayMS(Enter_ISP_Params.PinStabDelayMS);
 101                 }
 102         }
 103
 104         Endpoint_Write_Byte(CMD_ENTER_PROGMODE_ISP);
 105         Endpoint_Write_Byte(ResponseStatus);
 106         Endpoint_ClearIN();
 107 }
 108
 109 /** Handler for the CMD_LEAVE_ISP command, which releases the target from programming mode. */
 110 void ISPProtocol_LeaveISPMode(void)
 111 {
 112         struct
 113         {
 114                 uint8_t PreDelayMS;
 115                 uint8_t PostDelayMS;
 116         } Leave_ISP_Params;
 117
 118         Endpoint_Read_Stream_LE(&Leave_ISP_Params, sizeof(Leave_ISP_Params), NO_STREAM_CALLBACK);
 119
 120         Endpoint_ClearOUT();
 121         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 122         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 123
 124         /* Perform pre-exit delay, release the target /RESET, disable the SPI bus and perform the post-exit delay */
 125         ISPProtocol_DelayMS(Leave_ISP_Params.PreDelayMS);
 126         ISPTarget_ChangeTargetResetLine(false);
 127         SPI_ShutDown();
 128         ISPProtocol_DelayMS(Leave_ISP_Params.PostDelayMS);
 129
 130         /* Turn off the synchronous USART to terminate the recovery clock on XCK pin */
 131         UBRR1  = (F_CPU / 500000UL);
 132         UCSR1B = (1 << TXEN1);
 133         UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);
 134         DDRD  &= ~(1 << 5);
 135
 136         Endpoint_Write_Byte(CMD_LEAVE_PROGMODE_ISP);
 137         Endpoint_Write_Byte(STATUS_CMD_OK);
 138         Endpoint_ClearIN();
 139 }
 140
 141 /** Handler for the CMD_PROGRAM_FLASH_ISP and CMD_PROGRAM_EEPROM_ISP commands, writing out bytes,
 142  *  words or pages of data to the attached device.
 143  *
 144  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 145  */
 146 void ISPProtocol_ProgramMemory(uint8_t V2Command)
 147 {
 148         struct
 149         {
 150                 uint16_t BytesToWrite;
 151                 uint8_t  ProgrammingMode;
 152                 uint8_t  DelayMS;
 153                 uint8_t  ProgrammingCommands[3];
 154                 uint8_t  PollValue1;
 155                 uint8_t  PollValue2;
 156                 uint8_t  ProgData[256]; // Note, the Jungo driver has a very short ACK timeout period, need to buffer the
 157         } Write_Memory_Params;      // whole page and ACK the packet as fast as possible to prevent it from aborting
 158
 159         Endpoint_Read_Stream_LE(&Write_Memory_Params, (sizeof(Write_Memory_Params) -
 160                                                        sizeof(Write_Memory_Params.ProgData)), NO_STREAM_CALLBACK);
 161
 162
 163         Write_Memory_Params.BytesToWrite = SwapEndian_16(Write_Memory_Params.BytesToWrite);
 164
 165         if (Write_Memory_Params.BytesToWrite > sizeof(Write_Memory_Params.ProgData))
 166         {
 167                 Endpoint_ClearOUT();
 168                 Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 169                 Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 170
 171                 Endpoint_Write_Byte(V2Command);
 172                 Endpoint_Write_Byte(STATUS_CMD_FAILED);
 173                 Endpoint_ClearIN();
 174                 return;
 175         }
 176
 177         Endpoint_Read_Stream_LE(&Write_Memory_Params.ProgData, Write_Memory_Params.BytesToWrite, NO_STREAM_CALLBACK);
 178
 179         Endpoint_ClearOUT();
 180         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 181         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 182
 183         uint8_t  ProgrammingStatus = STATUS_CMD_OK;
 184         uint16_t PollAddress       = 0;
 185         uint8_t  PollValue         = (V2Command == CMD_PROGRAM_FLASH_ISP) ? Write_Memory_Params.PollValue1 :
 186                                                                             Write_Memory_Params.PollValue2;
 187         uint8_t* NextWriteByte = Write_Memory_Params.ProgData;
 188
 189         /* Check to see if the host has issued a SET ADDRESS command and we haven't sent a
 190          * LOAD EXTENDED ADDRESS command (if needed, used when operating beyond the 128KB
 191          * FLASH barrier) */
 192         if (MustSetAddress)
 193         {
 194                 if (CurrentAddress & (1UL << 31))
 195                   ISPTarget_LoadExtendedAddress();
 196
 197                 MustSetAddress = false;
 198         }
 199
 200         /* Check the programming mode desired by the host, either Paged or Word memory writes */
 201         if (Write_Memory_Params.ProgrammingMode & PROG_MODE_PAGED_WRITES_MASK)
 202         {
 203                 uint16_t StartAddress = (CurrentAddress & 0xFFFF);
 204
 205                 /* Paged mode memory programming */
 206                 for (uint16_t CurrentByte = 0; CurrentByte < Write_Memory_Params.BytesToWrite; CurrentByte++)
 207                 {
 208                         bool    IsOddByte   = (CurrentByte & 0x01);
 209                         uint8_t ByteToWrite = *(NextWriteByte++);
 210
 211                         SPI_SendByte(Write_Memory_Params.ProgrammingCommands[0]);
 212                         SPI_SendByte(CurrentAddress >> 8);
 213                         SPI_SendByte(CurrentAddress & 0xFF);
 214                         SPI_SendByte(ByteToWrite);
 215
 216                         /* AVR FLASH addressing requires us to modify the write command based on if we are writing a high
 217                          * or low byte at the current word address */
 218                         if (V2Command == CMD_PROGRAM_FLASH_ISP)
 219                           Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
 220
 221                         /* Check to see the write completion method, to see if we have a valid polling address */
 222                         if (!(PollAddress) && (ByteToWrite != PollValue))
 223                         {
 224                                 if (IsOddByte && (V2Command == CMD_PROGRAM_FLASH_ISP))
 225                                   Write_Memory_Params.ProgrammingCommands[2] |= READ_WRITE_HIGH_BYTE_MASK;
 226
 227                                 PollAddress = (CurrentAddress & 0xFFFF);
 228                         }
 229
 230                         if (IsOddByte || (V2Command == CMD_PROGRAM_EEPROM_ISP))
 231                           CurrentAddress++;
 232                 }
 233
 234                 /* If the current page must be committed, send the PROGRAM PAGE command to the target */
 235                 if (Write_Memory_Params.ProgrammingMode & PROG_MODE_COMMIT_PAGE_MASK)
 236                 {
 237                         SPI_SendByte(Write_Memory_Params.ProgrammingCommands[1]);
 238                         SPI_SendByte(StartAddress >> 8);
 239                         SPI_SendByte(StartAddress & 0xFF);
 240                         SPI_SendByte(0x00);
 241
 242                         /* Check if polling is possible, if not switch to timed delay mode */
 243                         if (!(PollAddress))
 244                         {
 245                                 Write_Memory_Params.ProgrammingMode &= ~PROG_MODE_PAGED_VALUE_MASK;
 246                                 Write_Memory_Params.ProgrammingMode |=  PROG_MODE_PAGED_TIMEDELAY_MASK;
 247                         }
 248
 249                         ProgrammingStatus = ISPTarget_WaitForProgComplete(Write_Memory_Params.ProgrammingMode, PollAddress, PollValue,
 250                                                                           Write_Memory_Params.DelayMS, Write_Memory_Params.ProgrammingCommands[2]);
 251                 }
 252         }
 253         else
 254         {
 255                 /* Word/byte mode memory programming */
 256                 for (uint16_t CurrentByte = 0; CurrentByte < Write_Memory_Params.BytesToWrite; CurrentByte++)
 257                 {
 258                         bool    IsOddByte   = (CurrentByte & 0x01);
 259                         uint8_t ByteToWrite = *(NextWriteByte++);
 260
 261                         SPI_SendByte(Write_Memory_Params.ProgrammingCommands[0]);
 262                         SPI_SendByte(CurrentAddress >> 8);
 263                         SPI_SendByte(CurrentAddress & 0xFF);
 264                         SPI_SendByte(ByteToWrite);
 265
 266                         /* AVR FLASH addressing requires us to modify the write command based on if we are writing a high
 267                          * or low byte at the current word address */
 268                         if (V2Command == CMD_PROGRAM_FLASH_ISP)
 269                           Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
 270
 271                         if (ByteToWrite != PollValue)
 272                         {
 273                                 if (IsOddByte && (V2Command == CMD_PROGRAM_FLASH_ISP))
 274                                   Write_Memory_Params.ProgrammingCommands[2] |= READ_WRITE_HIGH_BYTE_MASK;
 275
 276                                 PollAddress = (CurrentAddress & 0xFFFF);
 277                         }
 278
 279                         if (IsOddByte || (V2Command == CMD_PROGRAM_EEPROM_ISP))
 280                           CurrentAddress++;
 281
 282                         ProgrammingStatus = ISPTarget_WaitForProgComplete(Write_Memory_Params.ProgrammingMode, PollAddress, PollValue,
 283                                                                           Write_Memory_Params.DelayMS, Write_Memory_Params.ProgrammingCommands[2]);
 284
 285                         if (ProgrammingStatus != STATUS_CMD_OK)
 286                           break;
 287                 }
 288         }
 289
 290         Endpoint_Write_Byte(V2Command);
 291         Endpoint_Write_Byte(ProgrammingStatus);
 292         Endpoint_ClearIN();
 293 }
 294
 295 /** Handler for the CMD_READ_FLASH_ISP and CMD_READ_EEPROM_ISP commands, reading in bytes,
 296  *  words or pages of data from the attached device.
 297  *
 298  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 299  */
 300 void ISPProtocol_ReadMemory(uint8_t V2Command)
 301 {
 302         struct
 303         {
 304                 uint16_t BytesToRead;
 305                 uint8_t  ReadMemoryCommand;
 306         } Read_Memory_Params;
 307
 308         Endpoint_Read_Stream_LE(&Read_Memory_Params, sizeof(Read_Memory_Params), NO_STREAM_CALLBACK);
 309         Read_Memory_Params.BytesToRead = SwapEndian_16(Read_Memory_Params.BytesToRead);
 310
 311         Endpoint_ClearOUT();
 312         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 313         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 314
 315         Endpoint_Write_Byte(V2Command);
 316         Endpoint_Write_Byte(STATUS_CMD_OK);
 317
 318         /* Check to see if the host has issued a SET ADDRESS command and we haven't sent a
 319          * LOAD EXTENDED ADDRESS command (if needed, used when operating beyond the 128KB
 320          * FLASH barrier) */
 321         if (MustSetAddress)
 322         {
 323                 if (CurrentAddress & (1UL << 31))
 324                   ISPTarget_LoadExtendedAddress();
 325
 326                 MustSetAddress = false;
 327         }
 328
 329         /* Read each byte from the device and write them to the packet for the host */
 330         for (uint16_t CurrentByte = 0; CurrentByte < Read_Memory_Params.BytesToRead; CurrentByte++)
 331         {
 332                 /* Read the next byte from the desired memory space in the device */
 333                 SPI_SendByte(Read_Memory_Params.ReadMemoryCommand);
 334                 SPI_SendByte(CurrentAddress >> 8);
 335                 SPI_SendByte(CurrentAddress & 0xFF);
 336                 Endpoint_Write_Byte(SPI_ReceiveByte());
 337
 338                 /* Check if the endpoint bank is currently full, if so send the packet */
 339                 if (!(Endpoint_IsReadWriteAllowed()))
 340                 {
 341                         Endpoint_ClearIN();
 342                         Endpoint_WaitUntilReady();
 343                 }
 344
 345                 /* AVR FLASH addressing requires us to modify the read command based on if we are reading a high
 346                  * or low byte at the current word address */
 347                 if (V2Command == CMD_READ_FLASH_ISP)
 348                   Read_Memory_Params.ReadMemoryCommand ^= READ_WRITE_HIGH_BYTE_MASK;
 349
 350                 /* Only increment the current address if we have read both bytes in the current word when in FLASH
 351                  * read mode, or for each byte when in EEPROM read mode */
 352                 if (((CurrentByte & 0x01) && (V2Command == CMD_READ_FLASH_ISP)) || (V2Command == CMD_READ_EEPROM_ISP))
 353                   CurrentAddress++;
 354         }
 355
 356         Endpoint_Write_Byte(STATUS_CMD_OK);
 357
 358         bool IsEndpointFull = !(Endpoint_IsReadWriteAllowed());
 359         Endpoint_ClearIN();
 360
 361         /* Ensure last packet is a short packet to terminate the transfer */
 362         if (IsEndpointFull)
 363         {
 364                 Endpoint_WaitUntilReady();
 365                 Endpoint_ClearIN();
 366                 Endpoint_WaitUntilReady();
 367         }
 368 }
 369
 370 /** Handler for the CMD_CHI_ERASE_ISP command, clearing the target's FLASH memory. */
 371 void ISPProtocol_ChipErase(void)
 372 {
 373         struct
 374         {
 375                 uint8_t EraseDelayMS;
 376                 uint8_t PollMethod;
 377                 uint8_t EraseCommandBytes[4];
 378         } Erase_Chip_Params;
 379
 380         Endpoint_Read_Stream_LE(&Erase_Chip_Params, sizeof(Erase_Chip_Params), NO_STREAM_CALLBACK);
 381
 382         Endpoint_ClearOUT();
 383         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 384         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 385
 386         uint8_t ResponseStatus = STATUS_CMD_OK;
 387
 388         /* Send the chip erase commands as given by the host to the device */
 389         for (uint8_t SByte = 0; SByte < sizeof(Erase_Chip_Params.EraseCommandBytes); SByte++)
 390           SPI_SendByte(Erase_Chip_Params.EraseCommandBytes[SByte]);
 391
 392         /* Use appropriate command completion check as given by the host (delay or busy polling) */
 393         if (!(Erase_Chip_Params.PollMethod))
 394           ISPProtocol_DelayMS(Erase_Chip_Params.EraseDelayMS);
 395         else
 396           ResponseStatus = ISPTarget_WaitWhileTargetBusy();
 397
 398         Endpoint_Write_Byte(CMD_CHIP_ERASE_ISP);
 399         Endpoint_Write_Byte(ResponseStatus);
 400         Endpoint_ClearIN();
 401 }
 402
 403 /** Handler for the CMD_READ_FUSE_ISP, CMD_READ_LOCK_ISP, CMD_READ_SIGNATURE_ISP and CMD_READ_OSCCAL commands,
 404  *  reading the requested configuration byte from the device.
 405  *
 406  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 407  */
 408 void ISPProtocol_ReadFuseLockSigOSCCAL(uint8_t V2Command)
 409 {
 410         struct
 411         {
 412                 uint8_t RetByte;
 413                 uint8_t ReadCommandBytes[4];
 414         } Read_FuseLockSigOSCCAL_Params;
 415
 416         Endpoint_Read_Stream_LE(&Read_FuseLockSigOSCCAL_Params, sizeof(Read_FuseLockSigOSCCAL_Params), NO_STREAM_CALLBACK);
 417
 418         Endpoint_ClearOUT();
 419         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 420         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 421
 422         uint8_t ResponseBytes[4];
 423
 424         /* Send the Fuse or Lock byte read commands as given by the host to the device, store response */
 425         for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)
 426           ResponseBytes[RByte] = SPI_TransferByte(Read_FuseLockSigOSCCAL_Params.ReadCommandBytes[RByte]);
 427
 428         Endpoint_Write_Byte(V2Command);
 429         Endpoint_Write_Byte(STATUS_CMD_OK);
 430         Endpoint_Write_Byte(ResponseBytes[Read_FuseLockSigOSCCAL_Params.RetByte - 1]);
 431         Endpoint_Write_Byte(STATUS_CMD_OK);
 432         Endpoint_ClearIN();
 433 }
 434
 435 /** Handler for the CMD_WRITE_FUSE_ISP and CMD_WRITE_LOCK_ISP commands, writing the requested configuration
 436  *  byte to the device.
 437  *
 438  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 439  */
 440 void ISPProtocol_WriteFuseLock(uint8_t V2Command)
 441 {
 442         struct
 443         {
 444                 uint8_t WriteCommandBytes[4];
 445         } Write_FuseLockSig_Params;
 446
 447         Endpoint_Read_Stream_LE(&Write_FuseLockSig_Params, sizeof(Write_FuseLockSig_Params), NO_STREAM_CALLBACK);
 448
 449         Endpoint_ClearOUT();
 450         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 451         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 452
 453         /* Send the Fuse or Lock byte program commands as given by the host to the device */
 454         for (uint8_t SByte = 0; SByte < sizeof(Write_FuseLockSig_Params.WriteCommandBytes); SByte++)
 455           SPI_SendByte(Write_FuseLockSig_Params.WriteCommandBytes[SByte]);
 456
 457         Endpoint_Write_Byte(V2Command);
 458         Endpoint_Write_Byte(STATUS_CMD_OK);
 459         Endpoint_Write_Byte(STATUS_CMD_OK);
 460         Endpoint_ClearIN();
 461 }
 462
 463 /** Handler for the CMD_SPI_MULTI command, writing and reading arbitrary SPI data to and from the attached device. */
 464 void ISPProtocol_SPIMulti(void)
 465 {
 466         struct
 467         {
 468                 uint8_t TxBytes;
 469                 uint8_t RxBytes;
 470                 uint8_t RxStartAddr;
 471                 uint8_t TxData[255];
 472         } SPI_Multi_Params;
 473
 474         Endpoint_Read_Stream_LE(&SPI_Multi_Params, (sizeof(SPI_Multi_Params) - sizeof(SPI_Multi_Params.TxData)), NO_STREAM_CALLBACK);
 475         Endpoint_Read_Stream_LE(&SPI_Multi_Params.TxData, SPI_Multi_Params.TxBytes, NO_STREAM_CALLBACK);
 476
 477         Endpoint_ClearOUT();
 478         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 479         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 480
 481         Endpoint_Write_Byte(CMD_SPI_MULTI);
 482         Endpoint_Write_Byte(STATUS_CMD_OK);
 483
 484         uint8_t CurrTxPos = 0;
 485         uint8_t CurrRxPos = 0;
 486
 487         /* Write out bytes to transmit until the start of the bytes to receive is met */
 488         while (CurrTxPos < SPI_Multi_Params.RxStartAddr)
 489         {
 490                 if (CurrTxPos < SPI_Multi_Params.TxBytes)
 491                   SPI_SendByte(SPI_Multi_Params.TxData[CurrTxPos]);
 492                 else
 493                   SPI_SendByte(0);
 494
 495                 CurrTxPos++;
 496         }
 497
 498         /* Transmit remaining bytes with padding as needed, read in response bytes */
 499         while (CurrRxPos < SPI_Multi_Params.RxBytes)
 500         {
 501                 if (CurrTxPos < SPI_Multi_Params.TxBytes)
 502                   Endpoint_Write_Byte(SPI_TransferByte(SPI_Multi_Params.TxData[CurrTxPos++]));
 503                 else
 504                   Endpoint_Write_Byte(SPI_ReceiveByte());
 505
 506                 /* Check to see if we have filled the endpoint bank and need to send the packet */
 507                 if (!(Endpoint_IsReadWriteAllowed()))
 508                 {
 509                         Endpoint_ClearIN();
 510                         Endpoint_WaitUntilReady();
 511                 }
 512
 513                 CurrRxPos++;
 514         }
 515
 516         Endpoint_Write_Byte(STATUS_CMD_OK);
 517
 518         bool IsEndpointFull = !(Endpoint_IsReadWriteAllowed());
 519         Endpoint_ClearIN();
 520
 521         /* Ensure last packet is a short packet to terminate the transfer */
 522         if (IsEndpointFull)
 523         {
 524                 Endpoint_WaitUntilReady();
 525                 Endpoint_ClearIN();
 526                 Endpoint_WaitUntilReady();
 527         }
 528 }
 529
 530 /** Blocking delay for a given number of milliseconds.
 531  *
 532  *  \param[in] DelayMS  Number of milliseconds to delay for
 533  */
 534 void ISPProtocol_DelayMS(uint8_t DelayMS)
 535 {
 536         while (DelayMS-- && TimeoutMSRemaining)
 537         {
 538                 if (TimeoutMSRemaining)
 539                   TimeoutMSRemaining--;
 540
 541                 _delay_ms(1);
 542         }
 543 }
 544
 545 #endif