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                         /* EEPROM increments the address on each byte, flash needs to increment on each word */
 231                         if (IsOddByte || (V2Command == CMD_PROGRAM_EEPROM_ISP))
 232                           CurrentAddress++;
 233                 }
 234
 235                 /* If the current page must be committed, send the PROGRAM PAGE command to the target */
 236                 if (Write_Memory_Params.ProgrammingMode & PROG_MODE_COMMIT_PAGE_MASK)
 237                 {
 238                         SPI_SendByte(Write_Memory_Params.ProgrammingCommands[1]);
 239                         SPI_SendByte(StartAddress >> 8);
 240                         SPI_SendByte(StartAddress & 0xFF);
 241                         SPI_SendByte(0x00);
 242
 243                         /* Check if polling is possible, if not switch to timed delay mode */
 244                         if (!(PollAddress))
 245                         {
 246                                 Write_Memory_Params.ProgrammingMode &= ~PROG_MODE_PAGED_VALUE_MASK;
 247                                 Write_Memory_Params.ProgrammingMode |=  PROG_MODE_PAGED_TIMEDELAY_MASK;
 248                         }
 249
 250                         ProgrammingStatus = ISPTarget_WaitForProgComplete(Write_Memory_Params.ProgrammingMode, PollAddress, PollValue,
 251                                                                           Write_Memory_Params.DelayMS, Write_Memory_Params.ProgrammingCommands[2]);
 252
 253                         /* Check to see if the FLASH address has crossed the extended address boundary */
 254                         if ((V2Command == CMD_PROGRAM_FLASH_ISP) && !(CurrentAddress & 0xFFFF))
 255                           ISPTarget_LoadExtendedAddress();
 256                 }
 257         }
 258         else
 259         {
 260                 /* Word/byte mode memory programming */
 261                 for (uint16_t CurrentByte = 0; CurrentByte < Write_Memory_Params.BytesToWrite; CurrentByte++)
 262                 {
 263                         bool    IsOddByte   = (CurrentByte & 0x01);
 264                         uint8_t ByteToWrite = *(NextWriteByte++);
 265
 266                         SPI_SendByte(Write_Memory_Params.ProgrammingCommands[0]);
 267                         SPI_SendByte(CurrentAddress >> 8);
 268                         SPI_SendByte(CurrentAddress & 0xFF);
 269                         SPI_SendByte(ByteToWrite);
 270
 271                         /* AVR FLASH addressing requires us to modify the write command based on if we are writing a high
 272                          * or low byte at the current word address */
 273                         if (V2Command == CMD_PROGRAM_FLASH_ISP)
 274                           Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
 275
 276                         if (ByteToWrite != PollValue)
 277                         {
 278                                 if (IsOddByte && (V2Command == CMD_PROGRAM_FLASH_ISP))
 279                                   Write_Memory_Params.ProgrammingCommands[2] |= READ_WRITE_HIGH_BYTE_MASK;
 280
 281                                 PollAddress = (CurrentAddress & 0xFFFF);
 282                         }
 283
 284                         ProgrammingStatus = ISPTarget_WaitForProgComplete(Write_Memory_Params.ProgrammingMode, PollAddress, PollValue,
 285                                                                           Write_Memory_Params.DelayMS, Write_Memory_Params.ProgrammingCommands[2]);
 286
 287                         /* Abort the programming loop early if the byte/word programming failed */
 288                         if (ProgrammingStatus != STATUS_CMD_OK)
 289                           break;
 290
 291                         /* EEPROM just increments the address each byte, flash needs to increment on each word and
 292                          * also check to ensure that a LOAD EXTENDED ADDRESS command is issued each time the extended
 293                          * address boundary has been crossed */
 294                         if (V2Command == CMD_PROGRAM_EEPROM_ISP)
 295                         {
 296                                 CurrentAddress++;
 297                         }
 298                         else if (IsOddByte)
 299                         {
 300                                 if (!(++CurrentAddress & 0xFFFF))
 301                                   ISPTarget_LoadExtendedAddress();
 302                         }
 303                 }
 304         }
 305
 306         Endpoint_Write_Byte(V2Command);
 307         Endpoint_Write_Byte(ProgrammingStatus);
 308         Endpoint_ClearIN();
 309 }
 310
 311 /** Handler for the CMD_READ_FLASH_ISP and CMD_READ_EEPROM_ISP commands, reading in bytes,
 312  *  words or pages of data from the attached device.
 313  *
 314  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 315  */
 316 void ISPProtocol_ReadMemory(uint8_t V2Command)
 317 {
 318         struct
 319         {
 320                 uint16_t BytesToRead;
 321                 uint8_t  ReadMemoryCommand;
 322         } Read_Memory_Params;
 323
 324         Endpoint_Read_Stream_LE(&Read_Memory_Params, sizeof(Read_Memory_Params), NO_STREAM_CALLBACK);
 325         Read_Memory_Params.BytesToRead = SwapEndian_16(Read_Memory_Params.BytesToRead);
 326
 327         Endpoint_ClearOUT();
 328         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 329         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 330
 331         Endpoint_Write_Byte(V2Command);
 332         Endpoint_Write_Byte(STATUS_CMD_OK);
 333
 334         /* Check to see if the host has issued a SET ADDRESS command and we haven't sent a
 335          * LOAD EXTENDED ADDRESS command (if needed, used when operating beyond the 128KB
 336          * FLASH barrier) */
 337         if (MustSetAddress)
 338         {
 339                 if (CurrentAddress & (1UL << 31))
 340                   ISPTarget_LoadExtendedAddress();
 341
 342                 MustSetAddress = false;
 343         }
 344
 345         /* Read each byte from the device and write them to the packet for the host */
 346         for (uint16_t CurrentByte = 0; CurrentByte < Read_Memory_Params.BytesToRead; CurrentByte++)
 347         {
 348                 /* Read the next byte from the desired memory space in the device */
 349                 SPI_SendByte(Read_Memory_Params.ReadMemoryCommand);
 350                 SPI_SendByte(CurrentAddress >> 8);
 351                 SPI_SendByte(CurrentAddress & 0xFF);
 352                 Endpoint_Write_Byte(SPI_ReceiveByte());
 353
 354                 /* Check if the endpoint bank is currently full, if so send the packet */
 355                 if (!(Endpoint_IsReadWriteAllowed()))
 356                 {
 357                         Endpoint_ClearIN();
 358                         Endpoint_WaitUntilReady();
 359                 }
 360
 361                 /* AVR FLASH addressing requires us to modify the read command based on if we are reading a high
 362                  * or low byte at the current word address */
 363                 if (V2Command == CMD_READ_FLASH_ISP)
 364                   Read_Memory_Params.ReadMemoryCommand ^= READ_WRITE_HIGH_BYTE_MASK;
 365
 366                 /* EEPROM just increments the address each byte, flash needs to increment on each word and
 367                  * also check to ensure that a LOAD EXTENDED ADDRESS command is issued each time the extended
 368                  * address boundary has been crossed */
 369                 if (V2Command == CMD_READ_EEPROM_ISP)
 370                 {
 371                         CurrentAddress++;
 372                 }
 373                 else if (CurrentByte & 0x01)
 374                 {
 375                         if (!(++CurrentAddress & 0xFFFF))
 376                           ISPTarget_LoadExtendedAddress();
 377                 }
 378         }
 379
 380         Endpoint_Write_Byte(STATUS_CMD_OK);
 381
 382         bool IsEndpointFull = !(Endpoint_IsReadWriteAllowed());
 383         Endpoint_ClearIN();
 384
 385         /* Ensure last packet is a short packet to terminate the transfer */
 386         if (IsEndpointFull)
 387         {
 388                 Endpoint_WaitUntilReady();
 389                 Endpoint_ClearIN();
 390                 Endpoint_WaitUntilReady();
 391         }
 392 }
 393
 394 /** Handler for the CMD_CHI_ERASE_ISP command, clearing the target's FLASH memory. */
 395 void ISPProtocol_ChipErase(void)
 396 {
 397         struct
 398         {
 399                 uint8_t EraseDelayMS;
 400                 uint8_t PollMethod;
 401                 uint8_t EraseCommandBytes[4];
 402         } Erase_Chip_Params;
 403
 404         Endpoint_Read_Stream_LE(&Erase_Chip_Params, sizeof(Erase_Chip_Params), NO_STREAM_CALLBACK);
 405
 406         Endpoint_ClearOUT();
 407         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 408         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 409
 410         uint8_t ResponseStatus = STATUS_CMD_OK;
 411
 412         /* Send the chip erase commands as given by the host to the device */
 413         for (uint8_t SByte = 0; SByte < sizeof(Erase_Chip_Params.EraseCommandBytes); SByte++)
 414           SPI_SendByte(Erase_Chip_Params.EraseCommandBytes[SByte]);
 415
 416         /* Use appropriate command completion check as given by the host (delay or busy polling) */
 417         if (!(Erase_Chip_Params.PollMethod))
 418           ISPProtocol_DelayMS(Erase_Chip_Params.EraseDelayMS);
 419         else
 420           ResponseStatus = ISPTarget_WaitWhileTargetBusy();
 421
 422         Endpoint_Write_Byte(CMD_CHIP_ERASE_ISP);
 423         Endpoint_Write_Byte(ResponseStatus);
 424         Endpoint_ClearIN();
 425 }
 426
 427 /** Handler for the CMD_READ_FUSE_ISP, CMD_READ_LOCK_ISP, CMD_READ_SIGNATURE_ISP and CMD_READ_OSCCAL commands,
 428  *  reading the requested configuration byte from the device.
 429  *
 430  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 431  */
 432 void ISPProtocol_ReadFuseLockSigOSCCAL(uint8_t V2Command)
 433 {
 434         struct
 435         {
 436                 uint8_t RetByte;
 437                 uint8_t ReadCommandBytes[4];
 438         } Read_FuseLockSigOSCCAL_Params;
 439
 440         Endpoint_Read_Stream_LE(&Read_FuseLockSigOSCCAL_Params, sizeof(Read_FuseLockSigOSCCAL_Params), NO_STREAM_CALLBACK);
 441
 442         Endpoint_ClearOUT();
 443         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 444         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 445
 446         uint8_t ResponseBytes[4];
 447
 448         /* Send the Fuse or Lock byte read commands as given by the host to the device, store response */
 449         for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)
 450           ResponseBytes[RByte] = SPI_TransferByte(Read_FuseLockSigOSCCAL_Params.ReadCommandBytes[RByte]);
 451
 452         Endpoint_Write_Byte(V2Command);
 453         Endpoint_Write_Byte(STATUS_CMD_OK);
 454         Endpoint_Write_Byte(ResponseBytes[Read_FuseLockSigOSCCAL_Params.RetByte - 1]);
 455         Endpoint_Write_Byte(STATUS_CMD_OK);
 456         Endpoint_ClearIN();
 457 }
 458
 459 /** Handler for the CMD_WRITE_FUSE_ISP and CMD_WRITE_LOCK_ISP commands, writing the requested configuration
 460  *  byte to the device.
 461  *
 462  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 463  */
 464 void ISPProtocol_WriteFuseLock(uint8_t V2Command)
 465 {
 466         struct
 467         {
 468                 uint8_t WriteCommandBytes[4];
 469         } Write_FuseLockSig_Params;
 470
 471         Endpoint_Read_Stream_LE(&Write_FuseLockSig_Params, sizeof(Write_FuseLockSig_Params), NO_STREAM_CALLBACK);
 472
 473         Endpoint_ClearOUT();
 474         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 475         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 476
 477         /* Send the Fuse or Lock byte program commands as given by the host to the device */
 478         for (uint8_t SByte = 0; SByte < sizeof(Write_FuseLockSig_Params.WriteCommandBytes); SByte++)
 479           SPI_SendByte(Write_FuseLockSig_Params.WriteCommandBytes[SByte]);
 480
 481         Endpoint_Write_Byte(V2Command);
 482         Endpoint_Write_Byte(STATUS_CMD_OK);
 483         Endpoint_Write_Byte(STATUS_CMD_OK);
 484         Endpoint_ClearIN();
 485 }
 486
 487 /** Handler for the CMD_SPI_MULTI command, writing and reading arbitrary SPI data to and from the attached device. */
 488 void ISPProtocol_SPIMulti(void)
 489 {
 490         struct
 491         {
 492                 uint8_t TxBytes;
 493                 uint8_t RxBytes;
 494                 uint8_t RxStartAddr;
 495                 uint8_t TxData[255];
 496         } SPI_Multi_Params;
 497
 498         Endpoint_Read_Stream_LE(&SPI_Multi_Params, (sizeof(SPI_Multi_Params) - sizeof(SPI_Multi_Params.TxData)), NO_STREAM_CALLBACK);
 499         Endpoint_Read_Stream_LE(&SPI_Multi_Params.TxData, SPI_Multi_Params.TxBytes, NO_STREAM_CALLBACK);
 500
 501         Endpoint_ClearOUT();
 502         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
 503         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 504
 505         Endpoint_Write_Byte(CMD_SPI_MULTI);
 506         Endpoint_Write_Byte(STATUS_CMD_OK);
 507
 508         uint8_t CurrTxPos = 0;
 509         uint8_t CurrRxPos = 0;
 510
 511         /* Write out bytes to transmit until the start of the bytes to receive is met */
 512         while (CurrTxPos < SPI_Multi_Params.RxStartAddr)
 513         {
 514                 if (CurrTxPos < SPI_Multi_Params.TxBytes)
 515                   SPI_SendByte(SPI_Multi_Params.TxData[CurrTxPos]);
 516                 else
 517                   SPI_SendByte(0);
 518
 519                 CurrTxPos++;
 520         }
 521
 522         /* Transmit remaining bytes with padding as needed, read in response bytes */
 523         while (CurrRxPos < SPI_Multi_Params.RxBytes)
 524         {
 525                 if (CurrTxPos < SPI_Multi_Params.TxBytes)
 526                   Endpoint_Write_Byte(SPI_TransferByte(SPI_Multi_Params.TxData[CurrTxPos++]));
 527                 else
 528                   Endpoint_Write_Byte(SPI_ReceiveByte());
 529
 530                 /* Check to see if we have filled the endpoint bank and need to send the packet */
 531                 if (!(Endpoint_IsReadWriteAllowed()))
 532                 {
 533                         Endpoint_ClearIN();
 534                         Endpoint_WaitUntilReady();
 535                 }
 536
 537                 CurrRxPos++;
 538         }
 539
 540         Endpoint_Write_Byte(STATUS_CMD_OK);
 541
 542         bool IsEndpointFull = !(Endpoint_IsReadWriteAllowed());
 543         Endpoint_ClearIN();
 544
 545         /* Ensure last packet is a short packet to terminate the transfer */
 546         if (IsEndpointFull)
 547         {
 548                 Endpoint_WaitUntilReady();
 549                 Endpoint_ClearIN();
 550                 Endpoint_WaitUntilReady();
 551         }
 552 }
 553
 554 /** Blocking delay for a given number of milliseconds.
 555  *
 556  *  \param[in] DelayMS  Number of milliseconds to delay for
 557  */
 558 void ISPProtocol_DelayMS(uint8_t DelayMS)
 559 {
 560         while (DelayMS-- && TimeoutMSRemaining)
 561         {
 562                 if (TimeoutMSRemaining)
 563                   TimeoutMSRemaining--;
 564
 565                 _delay_ms(1);
 566         }
 567 }
 568
 569 #endif