+ /* Wait for the start bit when receiving */\r
+ if ((SoftUSART_BitCount == BITS_IN_FRAME) && (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK))\r
+ return;\r
+ \r
+ /* Shift in the bit one less than the frame size in position, so that the start bit will eventually\r
+ * be discarded leaving the data to be byte-aligned for quick access */\r
+ if (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK)\r
+ SoftUSART_Data |= (1 << (BITS_IN_FRAME - 1));\r
+\r
+ SoftUSART_Data >>= 1;\r
+ SoftUSART_BitCount--;\r
+ }\r
+ else\r
+ {\r
+ /* If at falling clock edge and we are in receive mode, abort */\r
+ if (!IsSending)\r
+ return;\r
+\r
+ /* Set the data line to the next bit value */\r
+ if (SoftUSART_Data & 0x01)\r
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;\r
+ else\r
+ BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK; \r
+\r
+ SoftUSART_Data >>= 1;\r
+ SoftUSART_BitCount--;\r
+ }\r
+}\r
+#endif\r
+\r
+/** Enables the target's PDI interface, holding the target in reset until PDI mode is exited. */\r
+void PDITarget_EnableTargetPDI(void)\r
+{\r
+#if defined(PDI_VIA_HARDWARE_USART)\r
+ /* Set Tx and XCK as outputs, Rx as input */\r
+ DDRD |= (1 << 5) | (1 << 3);\r
+ DDRD &= ~(1 << 2);\r
+ \r
+ /* Set DATA line high for at least 90ns to disable /RESET functionality */\r
+ PORTD |= (1 << 3);\r
+ asm volatile ("NOP"::);\r
+ asm volatile ("NOP"::);\r
+ \r
+ /* Set up the synchronous USART for XMEGA communications - \r
+ 8 data bits, even parity, 2 stop bits */\r
+ UBRR1 = (F_CPU / 1000000UL);\r
+ UCSR1B = (1 << TXEN1);\r
+ UCSR1C = (1 << UMSEL10) | (1 << UPM11) | (1 << USBS1) | (1 << UCSZ11) | (1 << UCSZ10) | (1 << UCPOL1);\r
+\r
+ /* Send two BREAKs of 12 bits each to enable PDI interface (need at least 16 idle bits) */\r
+ PDITarget_SendBreak();\r
+ PDITarget_SendBreak();\r
+#else\r
+ /* Set DATA and CLOCK lines to outputs */\r
+ BITBANG_PDIDATA_DDR |= BITBANG_PDIDATA_MASK;\r
+ BITBANG_PDICLOCK_DDR |= BITBANG_PDICLOCK_MASK;\r
+ \r
+ /* Set DATA line high for at least 90ns to disable /RESET functionality */\r
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;\r
+ asm volatile ("NOP"::);\r
+ asm volatile ("NOP"::);\r
+\r
+ /* Fire timer compare ISR every 100 cycles to manage the software USART */\r
+ OCR1A = 80;\r
+ TCCR1B = (1 << WGM12) | (1 << CS10);\r
+ TIMSK1 = (1 << OCIE1A);\r
+ \r
+ PDITarget_SendBreak();\r
+ PDITarget_SendBreak();\r
+#endif\r
+}\r
+\r
+/** Disables the target's PDI interface, exits programming mode and starts the target's application. */\r
+void PDITarget_DisableTargetPDI(void)\r
+{\r
+#if defined(PDI_VIA_HARDWARE_USART)\r
+ /* Turn off receiver and transmitter of the USART, clear settings */\r
+ UCSR1A |= (1 << TXC1) | (1 << RXC1);\r
+ UCSR1B = 0;\r
+ UCSR1C = 0;\r
+\r
+ /* Set all USART lines as input, tristate */\r
+ DDRD &= ~((1 << 5) | (1 << 3));\r
+ PORTD &= ~((1 << 5) | (1 << 3) | (1 << 2));\r
+#else\r
+ /* Set DATA and CLOCK lines to inputs */\r
+ BITBANG_PDIDATA_DDR &= ~BITBANG_PDIDATA_MASK;\r
+ BITBANG_PDICLOCK_DDR &= ~BITBANG_PDICLOCK_MASK;\r
+ \r
+ /* Tristate DATA and CLOCK lines */\r
+ BITBANG_PDIDATA_PORT &= ~BITBANG_PDIDATA_MASK;\r
+ BITBANG_PDICLOCK_PORT &= ~BITBANG_PDICLOCK_MASK;\r
+\r
+ TCCR0B = 0;\r
+#endif\r
+}\r
+\r
+/** Sends a byte via the USART.\r
+ *\r
+ * \param[in] Byte Byte to send through the USART\r
+ */\r
+void PDITarget_SendByte(const uint8_t Byte)\r
+{\r
+#if defined(PDI_VIA_HARDWARE_USART)\r
+ /* Switch to Tx mode if currently in Rx mode */\r
+ if (!(IsSending))\r
+ {\r
+ PORTD |= (1 << 3);\r
+ DDRD |= (1 << 3);\r
+\r
+ UCSR1B |= (1 << TXEN1);\r
+ UCSR1B &= ~(1 << RXEN1);\r
+ \r
+ IsSending = true;\r
+ }\r
+ \r
+ /* Wait until there is space in the hardware Tx buffer before writing */\r
+ while (!(UCSR1A & (1 << UDRE1)));\r
+ UCSR1A |= (1 << TXC1);\r
+ UDR1 = Byte;\r
+#else\r
+ /* Switch to Tx mode if currently in Rx mode */\r
+ if (!(IsSending))\r
+ {\r
+ BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;\r
+ BITBANG_PDIDATA_DDR |= BITBANG_PDIDATA_MASK;\r
+\r
+ IsSending = true;\r
+ }\r
+\r
+ /* Calculate the new USART frame data here while while we wait for a previous byte (if any) to finish sending */\r
+ uint16_t NewUSARTData = ((1 << 11) | (1 << 10) | (0 << 9) | ((uint16_t)Byte << 1) | (0 << 0));\r