3  *  This file contains special DoxyGen information for the generation of the main page and other special
 
   4  *  documentation pages. It is not a project source file.
 
   7 /** \page Page_Migration Migrating from Older Versions
 
   9  *  Below is migration information for updating existing projects based on previous versions of the LUFA library
 
  10  *  to the next version released. It does not indicate all new additions to the library in each version change, only
 
  11  *  areas relevant to making older projects compatible with the API changes of each new release.
 
  13  * \section Sec_MigrationXXXXXX Migrating from 090810 to XXXXXX
 
  15  *  <b>Non-USB Library Components</b>
 
  16  *    - The ADC_Off() function has been renamed to \ref ADC_ShutDown() to be consistent with the rest of the library.
 
  17  *    - The Dataflash_Init() routine no longer initializes the SPI bus - the SPI bus should be initialized manually via a
 
  18  *      call to SPI_Init() before using the Dataflash driver
 
  19  *    - The SPI_Init() routine's parameters have changed, so that the clock polarity and data sampling modes can be set. See
 
  20  *      the SPI_Init() function documentation for more details
 
  22  * \section Sec_Migration090810 Migrating from 090605 to 090810
 
  25  *    - The "Simple Scheduler" has been <i>deprecated</i>, as it was little more than an abtracted loop and caused much confusion.
 
  26  *      User applications using the scheduler should switch to regular loops instead. The scheduler code will be removed in a future
 
  28  *    - The "Dynamic Memory Block Allocator" has been removed, as it was unused in (and unrelated to) the LUFA library and never
 
  29  *      used in user applications. The library is available from the author's website for those wishing to still use it in their
 
  32  *  <b>Non-USB Library Components</b>
 
  33  *    - The ATTR_NOINLINE function attribute macro has been renamed to ATTR_NO_INLINE to be in line with the rest of the function attribute
 
  36  *  <b>Library Demos</b>
 
  37  *    - Most demos now have a corresponding Class Driver implementation, which uses the new internal library class drivers for the standard
 
  38  *      USB classes. This allows for more rapid device and host development, and so should be used in preference to the low level APIs where
 
  39  *      possible so that fixes to the class drivers propagate to all applications which use them automatically with each new LUFA release.
 
  42  *    - The HIDParser.c module has moved from LUFA/Drivers/USB/Class/ to LUFA/Drivers/USB/Class/Host/.
 
  43  *    - The \ref USB_GetDeviceConfigDescriptor() function now requires the desired configuration index within the device as its first
 
  44  *      parameter, to add support for multi-configuration devices. Existing code should use a configuration index of 1 to indicate the
 
  45  *      first configuration descriptor within the device.
 
  46  *    - The non-standard "Ready" host state has been removed. Existing \ref HOST_STATE_Configured code should be moved to the end of
 
  47  *      the existing \ref HOST_STATE_Addressed state, and the existing HOST_STATE_Ready state code should be moved to the \ref HOST_STATE_Configured
 
  49  *    - The USB_IsConnected global has been removed, as it is too vague for general use. Test \ref USB_HostState explicitly to ensure the host is
 
  50  *      in the desired state instead.
 
  51  *    - The USB event names have been changed and their firing conditions changed to properly seperate out Host mode events from Device mode
 
  52  *      events. See the \ref Group_Events page for details on the new event names and firing conditions.
 
  55  *    - The \ref CALLBACK_USB_GetDescriptor() function now takes an extra parameter to specify the descriptor's memory space so that
 
  56  *      descriptors in mixed memory spaces can be used. The previous functionality can be returned by defining the USE_FLASH_DESCRIPTORS
 
  57  *      token in the project makefile to fix all descriptors into FLASH space and remove the extra function parameter.
 
  58  *    - The USB_IsSuspended global has been removed - test \ref USB_DeviceState against \ref DEVICE_STATE_Suspended instead.
 
  59  *    - The USB_IsConnected global has been removed, as it is too vague for general use. Test \ref USB_DeviceState explicitly to ensure the device
 
  60  *      is in the desired state instead.
 
  61  *    - The VBUS events have been removed, as they are already exposed to the user via the USB_Connect and USB_Disconnect events.
 
  62  *    - The USB event names have been changed and their firing conditions changed to properly seperate out Host mode events from Device mode
 
  63  *      events. See the \ref Group_Events page for details on the new event names and firing conditions. *
 
  65  * \section Sec_Migration090605 Migrating from 090510 to 090605
 
  68  *    - Support for non-control data endpoint interrupts has been dropped due to many issues in the implementation. All existing
 
  69  *      projects using interrupts on non-control endpoints should switch to polling. For control interrupts, the library can
 
  70  *      manage the control endpoint via interrupts automatically by compiling with the INTERRUPT_CONTROL_ENDPOINT token defined.
 
  71  *    - The DESCRIPTOR_ADDRESS() macro has been removed. User applications should use normal casts to obtain a descriptor's memory
 
  73  *    - The library events system has been rewritten, so that all macros have been removed to allow for clearer user code. See
 
  74  *      \ref Group_Events for new API details.
 
  75  *    - The STREAM_CALLBACK() macro has been removed. User applications should replace all instances of the macro with regular
 
  76  *      function signatures of a function accepting no arguments and returning a uint8_t value.
 
  77  *    - The Event_DeviceError() event no longer exists, as its sole caller (unlinked USB_GetDescriptor() function) now produces a
 
  78  *      compilation error rather than a runtime error. The StdDescriptors.c file no longer exists as a result, and should be removed
 
  79  *      from project makefiles.
 
  80  *    - The USB_GetDescriptor() function has been renamed to CALLBACK_USB_GetDescriptor() to be in line with the new CALLBACK_ function
 
  81  *      prefixes for functions which *must* be implemented in the user application.
 
  84  *    - Support for non-control data pipe interrupts has been dropped due to many issues in the implementation. All existing
 
  85  *      projects using interrupts on non-control pipes should switch to polling.
 
  86  *    - The library events system has been rewritten, so that all macros have been removed to allow for clearer user code. See
 
  87  *      \ref Group_Events for new API details.
 
  88  *    - The STREAM_CALLBACK() macro has been removed. User applications should replace all instances of the macro with regular
 
  89  *      function signatures of a function accepting no arguments and returning a uint8_t value.
 
  90  *    - The DESCRIPTOR_COMPARATOR() macro has been removed. User applications should replace all instances of the macro with
 
  91  *      regular function signatures of a function accepting a void pointer to the descriptor to test, and returning a uint8_t value.
 
  94  * \section Sec_Migration090510 Migrating from 090401 to 090510
 
  97  *    - The ButtLoadTag.h header has been removed, as it was never used for its intended purpose. Projects should either remove all
 
  98  *      BUTTLOADTAG elements, or download and extract ButtLoadTag.h header from the ButtLoad project.
 
  99  *    - The Drivers/AT90USBXXX directory has been renamed to Drivers/Peripheral.
 
 100  *    - The Serial_Stream driver has been renamed to SerialStream to remain consistent with the rest of the library naming scheme.
 
 101  *    - The HWB driver has changed to the Buttons driver. See the board Buttons driver documentation for the new API.
 
 103  *  <b>Dual Role Mode</b>
 
 104  *    - The USB_PowerOnFail even has been renamed to USB_InitFailure.
 
 105  *    - The functions in OTG.h have been renamed to remain more consistent with the library API. See the functions in OTG.h for more
 
 108  *  <b>Library Demos</b>
 
 109  *    - Most demos, bootloaders and applications have had significant changes from previous versions. Applications built off of any
 
 110  *      library demos should update to the latest versions.
 
 113  *    - The Endpoint_ClearCurrentBank() macro has been removed, and is now replaced with the Endpoint_ClearIN(), Endpoint_ClearOUT() 
 
 114  *      macros. See Endpoint.h documentation for more details on the new endpoint management macros.
 
 115  *    - The Endpoint_ReadWriteAllowed() macro has been renamed to Endpoint_IsReadWriteAllowed() to be more consistent with the rest of
 
 116  *      the API naming scheme.
 
 117  *    - The Endpoint_IsSetupINReady() and Endpoint_IsSetupOutReceived() macros have been renamed to Endpoint_IsINReady() and
 
 118  *      Endpoint_IsOUTReceived() respectively.
 
 119  *    - The Endpoint_IsSetupReceived() macro has been renamed to Endpoint_IsSETUPReceived().
 
 120  *    - The Endpoint_ClearSetupReceived() macro has been renamed to Endpoint_ClearSETUP().
 
 121  *    - All endpoint read/write/discard aliases which did not have an explicitly endianness specifier (such as Endpoint_Read_Word()) have
 
 122  *      been removed for clarity. Existing projects should use the "_LE" suffix on such calls to use the explicit Little Endian versions.
 
 123  *    - The USB_UnhandledControlPacket event no longer has any parameters. User code should no longer attempt to read in the remainder of
 
 124  *      the Control Request header as all Control Request header data is now preloaded by the library and made available in the
 
 125  *      USB_ControlRequest structure.
 
 126  *    - The FEATURELESS_CONTROL_ONLY_DEVICE token has been renamed to CONTROL_ONLY_DEVICE.
 
 127  *    - The STATIC_ENDPOINT_CONFIGURATION is no longer applicable as the library will apply this optimization when appropriate automatically.
 
 128  *    - The values of the Endpoint_Stream_RW_ErrorCodes_t and Endpoint_ControlStream_RW_ErrorCodes_t enums have had the "ERROR_" portion
 
 129  *      of their names removed.
 
 132  *    - The USB_Host_SendControlRequest() function no longer automatically selects the Control pipe (pipe 0) to allow it to be used on
 
 133  *      other control type pipes. Care should be taken to ensure that the Control pipe is always selected before the function is called
 
 134  *      in existing projects where the Control pipe is to be operated on.
 
 135  *    - The USB Host management task now saves and restores the currently selected pipe before and after the task runs. Projects no longer
 
 136  *      need to manage this manually when calling the USB management task.
 
 137  *    - The Pipe_ClearCurrentBank() macro has been removed, and is now replaced with the Pipe_ClearIN(), Pipe_ClearOUT() macros. See
 
 138  *      Pipe.h documentation for more details on the new pipe management macros.
 
 139  *    - The Pipe_ReadWriteAllowed() macro has been renamed to Pipe_IsReadWriteAllowed() to be more consistent with the rest of the API
 
 141  *    - The Pipe_IsSetupINReceived() and Pipe_IsOutReady() macros have been renamed to Pipe_IsINReceived() and Pipe_IsOUTReady()
 
 143  *    - The new Pipe_ClearSETUP() macro should be used to send SETUP transactions, rather than the previous Pipe_ClearSetupOUT() macro.
 
 144  *    - The Pipe_IsSetupSent() macro has been renamed to Pipe_IsSETUPSent().
 
 145  *    - The Pipe_ClearSetupSent() macro is no longer applicable and should be removed.
 
 146  *    - All pipe read/write/discard aliases which did not have an explicitly endianness specifier (such as Pipe_Read_Word()) have
 
 147  *      been removed for clarity. Existing projects should use the "_LE" suffix on such calls to use the explicit Little Endian versions.
 
 148  *    - The Host_IsResetBusDone() macro has been renamed to Host_IsBusResetComplete().
 
 149  *    - The Pipe_Ignore_Word() and Pipe_Ignore_DWord() functions have been renamed to Pipe_Discard_Word() and Pipe_Discard_DWord() to remain
 
 150  *      consistent with the rest of the pipe API.
 
 151  *    - It is no longer needed to manually include the headers from LUFA/Drivers/USB/Class, as they are now included along with the rest
 
 152  *      of the USB headers when LUFA/Drivers/USB/USB.h is included.
 
 153  *    - Functions in the ConfigDescriptor.h header file no longer have "Host_" as part of their names.
 
 154  *    - The ProcessHIDReport() has been renamed to USB_ProcessHIDReport(), GetReportItemInfo() has been renamed to USB_GetHIDReportItemInfo()
 
 155  *      and SetReportItemInfo() has been renamed to USB_GetHIDReportItemInfo().
 
 156  *    - The values of the DSearch_Return_ErrorCodes_t and DSearch_Comp_Return_ErrorCodes_t enums have had their respective "Descriptor_Search"
 
 157  *      and "Descriptor_Search_Comp" prefixes changed to all caps.
 
 158  *    - The USB_HostRequest global has been renamed to USB_ControlRequest, and is used in Device mode also. The USB_Host_Request_Header_t
 
 159  *      structure type has been renamed to USB_Request_Header_t.
 
 160  *    - The values of the Pipe_Stream_RW_ErrorCodes_t enum have had the "ERROR_" portion of their names removed.
 
 163  * \section Sec_Migration090401 Migrating from 090209 to 090401
 
 166  *    - LUFA projects must now give the raw input clock frequency (before any prescaling) as a compile time constant "F_CLOCK",
 
 167  *      defined in the project makefile and passed to the compiler via the -D switch.
 
 168  *    - The makefile EEPROM programming targets for FLIP and dfu-programmer no longer program in the FLASH data in addition to the
 
 169  *      EEPROM data into the device. If both are to be programmed, both the EEPROM and FLASH programming targets must be called.
 
 170  *    - As the avr-libc macro has been corrected in recent avr-libc distributions, the SetSystemClockPrescaler() macro has been removed.
 
 171  *      Include <avr/power.h> and call clock_prescale_set(clock_div_1); instead on recent avr-libc distributions.
 
 173  *  <b>Library Demos</b>
 
 174  *    - The USBtoSerial demo now discards all data when not connected to a host, rather than buffering it for later transmission.
 
 175  *    - Most demos, bootloaders and applications have had their control request handling code corrected, to properly send the status
 
 176  *      stage in all handled requests. If you are using code based off one of the library demos, bootloaders or applications, you should
 
 177  *      update to the latest revisions.
 
 179  *  <b>Non-USB Library Components</b>
 
 180  *    - The ATTR_ALWAYSINLINE function attribute macro has been renamed to ATTR_ALWAYS_INLINE.
 
 181  *    - Custom board Dataflash drivers now require the implementation of Dataflash_SelectChipFromPage() and Dataflash_SendAddressBytes().
 
 184  *    - The NO_CLEARSET_FEATURE_REQUEST compile time token has been renamed to FEATURELESS_CONTROL_ONLY_DEVICE, and its function expanded
 
 185  *      to also remove parts of the Get Status chapter 9 request to further reduce code usage. On all applications currently using the 
 
 186  *      NO_CLEARSET_FEATURE_REQUEST compile time token, it can be replaced with the FEATURELESS_CONTROL_ONLY_DEVICE token with no further
 
 187  *      modifications required.
 
 190  * \section Sec_Migration090209 Migrating from 081217 to 090209
 
 193  *    - The ENDPOINT_MAX_ENDPOINTS constant has been renamed to the more appropriate name of ENDPOINT_TOTAL_ENDPOINTS.
 
 194  *    - The USB_STREAM_TIMEOUT_MS stream timeout default period has been extended to 100ms. This can be overridden in the user
 
 195  *      makefile if desired to restore the previous 50ms timeout.
 
 198  *    - The PIPE_MAX_ENDPOINTS constant has been renamed to the more appropriate name of PIPE_TOTAL_ENDPOINTS.
 
 199  *    - The USB_STREAM_TIMEOUT_MS stream timeout default period has been extended to 100ms. This can be overridden in the user
 
 200  *      makefile if desired to restore the previous 50ms timeout.
 
 201  *    - The USB_DeviceEnumerationFailed event now contains a second "SubErrorCode" parameter, giving the error code of the function
 
 203  *    - The HID_PARSE_Sucessful enum member constant has been corrected to HID_PARSE_Successful.
 
 205  *  <b>Non-USB Library Components</b>
 
 206  *    - The previous SPI_SendByte() functionality is now located in SPI_TransferByte(). SPI_SendByte() now discards the return byte
 
 207  *      for speed, to compliment the new SPI_ReceiveByte() function. If two-way SPI transfers are required, calls to SPI_SendByte()
 
 208  *      should be changed to SPI_TransferByte().
 
 209  *    - The serial driver now sets the Tx line as an output explicitly, and enables the pullup of the Rx line.
 
 210  *    - The Serial_Init() and SerialStream_Init() functions now take a second DoubleSpeed parameter, which indicates if the USART
 
 211  *      should be initialized in double speed mode - useful in some circumstances for attaining baud rates not usually possible at
 
 212  *      the given AVR clock speed.
 
 214  *  <b>Library Demos</b>
 
 215  *    - Most library demos have been enhanced and/or had errors corrected. All users of all demos should upgrade their codebase to
 
 216  *      the latest demo versions.
 
 219  * \section Sec_Migration171208 Migrating from V1.5.3 to 081217
 
 222  *    - The MyUSB project name has been changed to LUFA (Lightweight Framework for USB AVRs). All references to MyUSB, including macro names,
 
 223  *      have been changed to LUFA.
 
 225  *  <b>Library Demos</b>
 
 226  *    - The ReconfigureUSART() routine in the USBtoSerial demo was not being called after new line encoding
 
 227  *      parameters were set by the host. Projects built on the USBtoSerial code should update to the latest version.
 
 228  *    - The HID Parser now supports multiple report (on a single endpoint) HID devices. The MouseHostWithParser and
 
 229  *      KeyboardHostWithPaser demos use the updated API functions to function correctly on such devices. Projects
 
 230  *      built on either "WithParser" demo should update to the latest code.
 
 231  *    - The RNDIS demo TCP stack has been modified so that connections can be properly closed. It is still not
 
 232  *      recommended that the MyUSB RNDIS demo TCP/IP stack be used for anything other than demonstration purposes,
 
 233  *      as it is neither a full nor a standards compliant implementation.
 
 235  *  <b>Non-USB Library Components</b>
 
 236  *    - The Serial_IsCharRecieved() macro has been changed to the correct spelling of Serial_IsCharReceived() in Serial.h.
 
 239  *    - The MANUAL_PLL_CONTROL compile time token has been removed, and replaced with a USB_OPT_MANUAL_PLL mask
 
 240  *      to be used in the Options parameter of the USB_Init() function.
 
 241  *    - Calling USB_Init() now forces a complete USB interface reset and enumeration, even if the USB interface is
 
 242  *      currently initialized.
 
 243  *    - Interrupts are now disabled when processing control requests, to avoid problems with interrupts causing the library
 
 244  *      or user request processing code to exceed the strict USB timing requirements on control transfers.
 
 245  *    - The USB Reset event now resets and disables all device endpoints. If user code depends on endpoints remaining configured
 
 246  *      after a Reset event, it should be altered to explicitly re-initialize all user endpoints.
 
 247  *    - The prototype for the GetDescriptor function has been changed, as the return value was redundant. The function now
 
 248  *      returns the size of the descriptor, rather than passing it back via a parameter, or returns NO_DESCRIPTOR if the specified
 
 249  *      descriptor does not exist.
 
 250  *    - The NO_DESCRIPTOR_STRING macro has been renamed NO_DESCRIPTOR, and is now also used as a possible return value for the
 
 251  *      GetDescriptor function.
 
 254  *    - The MANUAL_PLL_CONTROL compile time token has been removed, and replaced with a USB_OPT_MANUAL_PLL mask
 
 255  *      to be used in the Options parameter of the USB_Init() function.
 
 256  *    - The HID report parser now supports multiple Report IDs. The HID report parser GetReportItemInfo() and
 
 257  *      SetReportItemInfo() routines now return a boolean, set if the requested report item was located in the
 
 258  *      current report. If sending a report to a multi-report device, the first byte of the report is automatically
 
 259  *      set to the report ID of the given report item.
 
 260  *    - Calling USB_Init() now forces a complete USB interface reset and enumeration, even if the USB interface is
 
 261  *      currently initialized.
 
 264  * \section Sec_Migration152 Migrating from V1.5.2 to V1.5.3
 
 266  *  <b>Library Demos</b>
 
 267  *    - Previously, all demos contained a serial number string descriptor, filled with all zeros. A serial number
 
 268  *      string is required in Mass Storage devices, or devices which are to retain settings when moved between
 
 269  *      ports on a machine. As people were not changing the serial number value, this was causing conflicts and so
 
 270  *      the serial number descriptor has been removed from all but the Mass Storage demo, which requires it.
 
 271  *    - The AudioOut and AudioIn demos did not previously silence their endpoints when the host has deactivated
 
 272  *      them. Projects built upon either demo should upgrade to the latest code.
 
 273  *    - The FEATURE_ENDPOINT macro has been renamed FEATURE_ENDPOINT_HALT, and is now correctly documented.
 
 274  *    - The MassStoreHost demo contained errors which caused it to lock up randomly on certain devices. Projects built
 
 275  *      on the MassStoreDemo code should update to the latest version.
 
 276  *    - The Interrupt type endpoint in the CDC based demos previously had a polling interval of 0x02, which caused
 
 277  *      problems on some Linux systems. This has been changed to 0xFF, projects built on the CDC demos should upgrade
 
 278  *      to the latest code.
 
 279  *    - The HID keyboard and mouse demos were not previously boot mode compatible. To enable boot mode support, projects
 
 280  *      built on the keyboard or mouse demos (or derivatives) should upgrade to the latest code.
 
 281  *    - The Mass Storage demo was not previously standards compliant. Projects built on the Mass Storage demo should
 
 282  *      upgrade to the latest code.
 
 283  *    - The USART was not being reconfigured after the host sent new encoding settings in the USBtoSerial demo. This was
 
 284  *      previously discovered and fixed, but the change was lost. Projects built on the USBtoSerial demo should update
 
 285  *      to the latest code.
 
 288  *    - The endpoint non-control stream functions now have a default timeout of 50ms between packets in the stream.
 
 289  *      If this timeout is exceeded, the function returns the new ENDPOINT_RWSTREAM_ERROR_Timeout error value. The
 
 290  *      timeout value can be overridden by defining the USB_STREAM_TIMEOUT_MS in the project makefile to the desired
 
 291  *      timeout duration in ms.
 
 292  *    - Rather than returning fixed values, the flags indicating if the device has Remote Wakeup currently enabled
 
 293  *      and/or is self-powered are now accessed and set through the new USB_RemoteWakeupEnabled and
 
 294  *      USB_CurrentlySelfPowered macros. See the DevChapter9.h documentation for more details.
 
 295  *    - All endpoint stream functions now require an extra Callback function parameter. Existing code may be updated
 
 296  *      to either supply NO_STREAM_CALLBACK as the extra parameter, or disable stream callbacks altogether by passing
 
 297  *      the token NO_STREAM_CALLBACKS to the compiler using the -D switch.
 
 300  *    - The pipe non-control stream functions now have a default timeout of 50ms between packets in the stream.
 
 301  *      If this timeout is exceeded, the function returns the new PIPE_RWSTREAM_ERROR_Timeout error value. The
 
 302  *      timeout value can be overridden by defining the USB_STREAM_TIMEOUT_MS in the project makefile to the desired
 
 303  *      timeout duration in ms.
 
 304  *    - CollectionPath_t has been renamed to HID_CollectionPath_t to be more in line with the other HID parser structures.
 
 305  *    - All pipe stream functions now require an extra Callback function parameter. Existing code may be updated
 
 306  *      to either supply NO_STREAM_CALLBACK as the extra parameter, or disable stream callbacks altogether by passing
 
 307  *      the token NO_STREAM_CALLBACKS to the compiler using the -D switch.
 
 310  * \section Sec_Migration151 Migrating from V1.5.1 to V1.5.2
 
 312  *  <b>Library Demos</b>
 
 313  *    - The RNDIS demo application has been updated so that it is functional on Linux under earlier implementations
 
 314  *      of the RNDIS specification, which had non-standard behaviour. Projects built upon the demo should upgrade
 
 315  *      to the latest code.
 
 316  *    - The DFU class bootloader has had several bugs corrected in this release. It is recommended that where
 
 317  *      possible any existing devices upgrade to the latest bootloader code.
 
 320  * \section Sec_Migration150 Migrating from V1.5.0 to V1.5.1
 
 322  *  <b>Library Demos</b>
 
 323  *    - The USBtoSerial demo was broken in the 1.5.0 release, due to incorrect register polling in place of the
 
 324  *      global "Transmitting" flag. The change has been reverted in this release. Projects built upon the demo
 
 325  *      should upgrade to the latest code.
 
 326  *    - The HID class demos did not implement the mandatory GetReport HID class request. Projects built upon the HID
 
 327  *      demos should upgrade to the latest code.
 
 328  *    - The HID class demos incorrectly reported themselves as boot-protocol enabled HID devices in their descriptors.
 
 329  *      Projects built upon the HID demos should upgrade to the latest code.
 
 330  *    - The MIDI device demo had incorrect AudioStreaming interface descriptors. Projects built upon the MIDI demo
 
 331  *      should upgrade to the latest code.
 
 332  *    - The AudioOut demo did not correctly tristate the speaker pins when USB was disconnected, wasting power.
 
 333  *      Projects built upon the AudioOut demo should upgrade to the latest code.
 
 336  * \section Sec_Migration141 Migrating from V1.4.1 to V1.5.0
 
 338  *  <b>Library Demos</b>
 
 339  *    - Previous versions of the library demos had incorrectly encoded BCD version numbers in the descriptors. To
 
 340  *      avoid such mistakes in the future, the VERSION_BCD macro has been added to StdDescriptors.h. Existing
 
 341  *      projects should at least manually correct the BCD version numbers, or preferably update the descriptors to
 
 342  *      encode the version number in BCD format using the new macro.
 
 343  *    - The mandatory GetReport class-specific request was accidentally omitted from previous versions of the demos
 
 344  *      based on the Human Interface Device (HID) class. This has been corrected, and any user projects based on the
 
 345  *      HID demos should also be updated accordingly.
 
 346  *    - The CDC demos now correctly send an empty packet directly after a full packet, to end the transmission.
 
 347  *      Failure to do this on projects which always or frequently send full packets will cause buffering issues on
 
 348  *      the host OS. All CDC user projects are advised to update their transmission routines in the same manner as
 
 349  *      the library CDC demos.
 
 350  *    - The previous interrupt-driven Endpoint/Pipe demos did not properly save and restore the currently selected
 
 351  *      Endpoint/Pipe when the ISR fired. This has been corrected - user projects based on the interrupt driven
 
 352  *      demos should also update to properly save and restore the selected Endpoint/Pipe.
 
 354  *  <b>Non-USB Library Components</b>
 
 355  *    - The Atomic.h and ISRMacro.h header files in MyUSB/Common have been removed, as the library is now only
 
 356  *      compatible with avr-libc library versions newer than the time before the functionality of the deleted
 
 357  *      headers was available.
 
 360  *    - The GetDescriptor function (see StdDescriptors.h) now has a new prototype, with altered parameter names and
 
 361  *      functions. Existing projects will need to update the GetDescriptor implementation to reflect the new API.
 
 362  *      The previously split Type and Index parameters are now passed as the original wValue parameter to the
 
 363  *      function, to make way for the USB specification wIndex parameter which is <i>not</i> the same as the
 
 364  *      previous Index parameter.
 
 365  *    - The USB_UnhandledControlPacket event (see Events.h) now has new parameter names, to be in line with the
 
 366  *      official USB specification. Existing code will need to be altered to use the new parameter names.
 
 367  *    - The USB_CreateEndpoints event (see Events.h) has been renamed to USB_ConfigurationChanged, which is more
 
 368  *      appropriate. It fires in an identical manner to the previously named event, thus the only change to be made
 
 369  *      is the event name itself in the user project.
 
 370  *    - The USB_Descriptor_Language_t structure no longer exists in StdDescriptors.h, as this was a
 
 371  *      pseudo-descriptor modelled on the string descriptor. It is replaced by the true USB_Descriptor_String_t type
 
 372  *      descriptor as indicated in the USB specification, thus all device code must be updated accordingly.
 
 373  *    - The names of several Endpoint macros have been changed to be more consistent with the rest of the library,
 
 374  *      with no implementation changes. This means that existing code can be altered to use the new macro names
 
 375  *      with no other considerations required. See Endpoint.h for the new macro names.
 
 376  *    - The previous version of the MassStorage demo had an incorrect value in the SCSI_Request_Sense_Response_t
 
 377  *      structure named SenseData in SCSI.c which caused some problems with some hosts. User projects based on this
 
 378  *      demo should correct the structure value to maintain compatibility across multiple OS platforms.
 
 379  *    - By default, the descriptor structures use the official USB specification names for the elements. Previous
 
 380  *      versions of the library used non-standard (but more verbose) names, which are still usable in the current
 
 381  *      and future releases when the correct compile time option is enabled. See the StdDescriptors.h file
 
 382  *      documentation for more details.
 
 385  *    - The USB_Host_Request_Header_t structure in HostChapter9.h (used for issuing control requests) has had its
 
 386  *      members renamed to the official USB specification names for requests. Existing code will need to be updated
 
 387  *      to use the new names.
 
 388  *    - The names of several Pipe macros have been changed to be more consistent with the rest of the library,
 
 389  *      with no implementation changes. This means that existing code can be altered to use the new macro names
 
 390  *      with no other considerations required. See Pipe.h for the new macro names.
 
 391  *    - By default, the descriptor structures use the official USB specification names for the elements. Previous
 
 392  *      versions of the library used non-standard (but more verbose) names, which are still usable in the current
 
 393  *      and future releases when the correct compile time option is enabled. See the StdDescriptors.h file
 
 394  *      documentation for more details.
 
 395  *    - The names of the macros in Host.h for controlling the SOF generation have been renamed, see the Host.h
 
 396  *      module documentation for the new macro names.
 
 398  *  <b>Dual Role Mode</b>
 
 399  *    - The OTG.h header file has been corrected so that the macros now perform their stated functions. Any existing
 
 400  *      projects using custom headers to fix the broken OTG header should now be altered to once again use the OTG
 
 401  *      header inside the library.
 
 402  *    - The USB_DeviceEnumerationComplete event (see Events.h) now also fires in Device mode, when the host has
 
 403  *      finished enumerating the device. Projects relying on the event only firing in Host mode should be updated
 
 404  *      so that the event action only occurs when the USB_Mode global is set to USB_MODE_HOST.