Endpoint_Read_Stream_LE(&Enter_ISP_Params, sizeof(Enter_ISP_Params), NO_STREAM_CALLBACK);\r
 \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
 \r
        uint8_t ResponseStatus = STATUS_CMD_FAILED;\r
                for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)\r
                {\r
                        ISPProtocol_DelayMS(Enter_ISP_Params.ByteDelay);\r
-                       ResponseBytes[RByte] = SPI_Transfer(Enter_ISP_Params.EnterProgBytes[RByte]);\r
+                       ResponseBytes[RByte] = SPI_TransferByte(Enter_ISP_Params.EnterProgBytes[RByte]);\r
                }\r
                \r
                /* Check if polling disabled, or if the polled value matches the expected value */\r
        Endpoint_Read_Stream_LE(&Leave_ISP_Params, sizeof(Leave_ISP_Params), NO_STREAM_CALLBACK);\r
        \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
 \r
        /* Perform pre-exit delay, release the target /RESET, disable the SPI bus and perform the post-exit delay */\r
        if (Write_Memory_Params.BytesToWrite > sizeof(Write_Memory_Params.ProgData))\r
        {\r
                Endpoint_ClearOUT();\r
+               Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
                Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
 \r
                Endpoint_Write_Byte(V2Command);\r
        Endpoint_Read_Stream_LE(&Write_Memory_Params.ProgData, Write_Memory_Params.BytesToWrite, NO_STREAM_CALLBACK);\r
 \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
 \r
        uint8_t  ProgrammingStatus = STATUS_CMD_OK;     \r
                        bool    IsOddByte   = (CurrentByte & 0x01);\r
                        uint8_t ByteToWrite = *(NextWriteByte++);\r
                \r
-                       SPI_Send(Write_Memory_Params.ProgrammingCommands[0]);\r
-                       SPI_Send(CurrentAddress >> 8);\r
-                       SPI_Send(CurrentAddress & 0xFF);\r
-                       SPI_Send(ByteToWrite);\r
+                       SPI_SendByte(Write_Memory_Params.ProgrammingCommands[0]);\r
+                       SPI_SendByte(CurrentAddress >> 8);\r
+                       SPI_SendByte(CurrentAddress & 0xFF);\r
+                       SPI_SendByte(ByteToWrite);\r
                        \r
                        /* AVR FLASH addressing requires us to modify the write command based on if we are writing a high\r
                         * or low byte at the current word address */\r
                /* If the current page must be committed, send the PROGRAM PAGE command to the target */\r
                if (Write_Memory_Params.ProgrammingMode & PROG_MODE_COMMIT_PAGE_MASK)\r
                {\r
-                       SPI_Send(Write_Memory_Params.ProgrammingCommands[1]);\r
-                       SPI_Send(StartAddress >> 8);\r
-                       SPI_Send(StartAddress & 0xFF);\r
-                       SPI_Send(0x00);\r
+                       SPI_SendByte(Write_Memory_Params.ProgrammingCommands[1]);\r
+                       SPI_SendByte(StartAddress >> 8);\r
+                       SPI_SendByte(StartAddress & 0xFF);\r
+                       SPI_SendByte(0x00);\r
                        \r
                        /* Check if polling is possible, if not switch to timed delay mode */\r
                        if (!(PollAddress))\r
                        bool    IsOddByte   = (CurrentByte & 0x01);\r
                        uint8_t ByteToWrite = *(NextWriteByte++);\r
                          \r
-                       SPI_Send(Write_Memory_Params.ProgrammingCommands[0]);\r
-                       SPI_Send(CurrentAddress >> 8);\r
-                       SPI_Send(CurrentAddress & 0xFF);\r
-                       SPI_Send(ByteToWrite);\r
+                       SPI_SendByte(Write_Memory_Params.ProgrammingCommands[0]);\r
+                       SPI_SendByte(CurrentAddress >> 8);\r
+                       SPI_SendByte(CurrentAddress & 0xFF);\r
+                       SPI_SendByte(ByteToWrite);\r
                        \r
                        /* AVR FLASH addressing requires us to modify the write command based on if we are writing a high\r
                         * or low byte at the current word address */\r
        Read_Memory_Params.BytesToRead = SwapEndian_16(Read_Memory_Params.BytesToRead);\r
        \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
        \r
        Endpoint_Write_Byte(V2Command);\r
        for (uint16_t CurrentByte = 0; CurrentByte < Read_Memory_Params.BytesToRead; CurrentByte++)\r
        {\r
                /* Read the next byte from the desired memory space in the device */\r
-               SPI_Send(Read_Memory_Params.ReadMemoryCommand);\r
-               SPI_Send(CurrentAddress >> 8);\r
-               SPI_Send(CurrentAddress & 0xFF);\r
-               Endpoint_Write_Byte(SPI_Receive());\r
+               SPI_SendByte(Read_Memory_Params.ReadMemoryCommand);\r
+               SPI_SendByte(CurrentAddress >> 8);\r
+               SPI_SendByte(CurrentAddress & 0xFF);\r
+               Endpoint_Write_Byte(SPI_ReceiveByte());\r
                \r
                /* Check if the endpoint bank is currently full, if so send the packet */\r
                if (!(Endpoint_IsReadWriteAllowed()))\r
        Endpoint_Read_Stream_LE(&Erase_Chip_Params, sizeof(Erase_Chip_Params), NO_STREAM_CALLBACK);\r
        \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
        \r
        uint8_t ResponseStatus = STATUS_CMD_OK;\r
        \r
        /* Send the chip erase commands as given by the host to the device */\r
        for (uint8_t SByte = 0; SByte < sizeof(Erase_Chip_Params.EraseCommandBytes); SByte++)\r
-         SPI_Send(Erase_Chip_Params.EraseCommandBytes[SByte]);\r
+         SPI_SendByte(Erase_Chip_Params.EraseCommandBytes[SByte]);\r
 \r
        /* Use appropriate command completion check as given by the host (delay or busy polling) */\r
        if (!(Erase_Chip_Params.PollMethod))\r
        Endpoint_Read_Stream_LE(&Read_FuseLockSigOSCCAL_Params, sizeof(Read_FuseLockSigOSCCAL_Params), NO_STREAM_CALLBACK);\r
 \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
 \r
        uint8_t ResponseBytes[4];\r
 \r
        /* Send the Fuse or Lock byte read commands as given by the host to the device, store response */\r
        for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)\r
-         ResponseBytes[RByte] = SPI_Transfer(Read_FuseLockSigOSCCAL_Params.ReadCommandBytes[RByte]);\r
+         ResponseBytes[RByte] = SPI_TransferByte(Read_FuseLockSigOSCCAL_Params.ReadCommandBytes[RByte]);\r
                \r
        Endpoint_Write_Byte(V2Command);\r
        Endpoint_Write_Byte(STATUS_CMD_OK);\r
        Endpoint_Read_Stream_LE(&Write_FuseLockSig_Params, sizeof(Write_FuseLockSig_Params), NO_STREAM_CALLBACK);\r
 \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
 \r
        /* Send the Fuse or Lock byte program commands as given by the host to the device */\r
        for (uint8_t SByte = 0; SByte < sizeof(Write_FuseLockSig_Params.WriteCommandBytes); SByte++)\r
-         SPI_Send(Write_FuseLockSig_Params.WriteCommandBytes[SByte]);\r
+         SPI_SendByte(Write_FuseLockSig_Params.WriteCommandBytes[SByte]);\r
                \r
        Endpoint_Write_Byte(V2Command);\r
        Endpoint_Write_Byte(STATUS_CMD_OK);\r
        Endpoint_Read_Stream_LE(&SPI_Multi_Params.TxData, SPI_Multi_Params.TxBytes, NO_STREAM_CALLBACK);\r
        \r
        Endpoint_ClearOUT();\r
+       Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
        \r
        Endpoint_Write_Byte(CMD_SPI_MULTI);\r
        while (CurrTxPos < SPI_Multi_Params.RxStartAddr)\r
        {\r
                if (CurrTxPos < SPI_Multi_Params.TxBytes)\r
-                 SPI_Send(SPI_Multi_Params.TxData[CurrTxPos]);\r
+                 SPI_SendByte(SPI_Multi_Params.TxData[CurrTxPos]);\r
                else\r
-                 SPI_Send(0);\r
+                 SPI_SendByte(0);\r
                \r
                CurrTxPos++;\r
        }\r
        while (CurrRxPos < SPI_Multi_Params.RxBytes)\r
        {\r
                if (CurrTxPos < SPI_Multi_Params.TxBytes)\r
-                 Endpoint_Write_Byte(SPI_Transfer(SPI_Multi_Params.TxData[CurrTxPos++]));\r
+                 Endpoint_Write_Byte(SPI_TransferByte(SPI_Multi_Params.TxData[CurrTxPos++]));\r
                else\r
-                 Endpoint_Write_Byte(SPI_Receive());\r
+                 Endpoint_Write_Byte(SPI_ReceiveByte());\r
                  \r
                /* Check to see if we have filled the endpoint bank and need to send the packet */\r
                if (!(Endpoint_IsReadWriteAllowed()))\r