Merge pull request #8082 from thinkyhead/bf2_xon_xoff_due

[2.0.x] Arduino Due XON/XOFF implementation

Marlin/src/HAL/HAL_AVR/MarlinSerial.cpp

@@ -84,7 +84,7 @@
     // Currently looking for: M108, M112, M410
     // If you alter the parser please don't forget to update the capabilities in Conditionals_post.h
 
-    FORCE_INLINE void emergency_parser(const unsigned char c) {
+    FORCE_INLINE void emergency_parser(const uint8_t c) {
 
       static e_parser_state state = state_RESET;
 
@@ -169,13 +169,16 @@
   #endif // EMERGENCY_PARSER
 
   FORCE_INLINE void store_rxd_char() {
+
     const ring_buffer_pos_t h = rx_buffer.head,
                             i = (ring_buffer_pos_t)(h + 1) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
 
+    // Read the character
+    const uint8_t c = M_UDRx;
+
     // If the character is to be stored at the index just before the tail
     // (such that the head would advance to the current tail), the buffer is
     // critical, so don't write the character or advance the head.
-    const char c = M_UDRx;
     if (i != rx_buffer.tail) {
       rx_buffer.buffer[h] = c;
       rx_buffer.head = i;
@@ -194,6 +197,7 @@
     #endif
 
     #if ENABLED(SERIAL_XON_XOFF)
+
       // for high speed transfers, we can use XON/XOFF protocol to do
       // software handshake and avoid overruns.
       if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XON_CHAR) {

Marlin/src/HAL/HAL_DUE/HAL_Due.h

@@ -29,37 +29,35 @@
 #ifndef _HAL_DUE_H
 #define _HAL_DUE_H
 
-// --------------------------------------------------------------------------
-// Includes
-// --------------------------------------------------------------------------
-
 #include <stdint.h>
 
 #include "Arduino.h"
 
 #include "fastio_Due.h"
 #include "watchdog_Due.h"
-
 #include "HAL_timers_Due.h"
 
-// --------------------------------------------------------------------------
+//
 // Defines
-// --------------------------------------------------------------------------
+//
 
 #if SERIAL_PORT == -1
   #define MYSERIAL SerialUSB
 #elif SERIAL_PORT == 0
-  #define MYSERIAL Serial
+  #define MYSERIAL customizedSerial
 #elif SERIAL_PORT == 1
-  #define MYSERIAL Serial1
+  #define MYSERIAL customizedSerial
 #elif SERIAL_PORT == 2
-  #define MYSERIAL Serial2
+  #define MYSERIAL customizedSerial
 #elif SERIAL_PORT == 3
-  #define MYSERIAL Serial3
+  #define MYSERIAL customizedSerial
 #endif
 
 #define _BV(bit) (1 << (bit))
 
+// We need the previous define before the include, or compilation bombs...
+#include "MarlinSerial_Due.h"
+
 #ifndef analogInputToDigitalPin
   #define analogInputToDigitalPin(p) ((p < 12u) ? (p) + 54u : -1)
 #endif
@@ -102,46 +100,43 @@ typedef int8_t pin_t;
 // Public Variables
 // --------------------------------------------------------------------------
 
-/** result of last ADC conversion */
-extern uint16_t HAL_adc_result;
+extern uint16_t HAL_adc_result;     // result of last ADC conversion
 
-// --------------------------------------------------------------------------
-// Public functions
-// --------------------------------------------------------------------------
-
-// Disable interrupts
-void cli(void);
-
-// Enable interrupts
-void sei(void);
-
-/** clear reset reason */
-void HAL_clear_reset_source (void);
+void cli(void);                     // Disable interrupts
+void sei(void);                     // Enable interrupts
 
-/** reset reason */
-uint8_t HAL_get_reset_source (void);
+void HAL_clear_reset_source(void);  // clear reset reason
+uint8_t HAL_get_reset_source(void); // get reset reason
 
 void _delay_ms(const int delay);
 
 int freeMemory(void);
 
-// SPI: Extended functions which take a channel number (hardware SPI only)
-/** Write single byte to specified SPI channel */
+/**
+ * SPI: Extended functions taking a channel number (hardware SPI only)
+ */
+
+// Write single byte to specified SPI channel
 void spiSend(uint32_t chan, byte b);
-/** Write buffer to specified SPI channel */
+
+// Write buffer to specified SPI channel
 void spiSend(uint32_t chan, const uint8_t* buf, size_t n);
-/** Read single byte from specified SPI channel */
+
+// Read single byte from specified SPI channel
 uint8_t spiRec(uint32_t chan);
 
+/**
+ * EEPROM
+ */
 
-// EEPROM
 void eeprom_write_byte(unsigned char *pos, unsigned char value);
 unsigned char eeprom_read_byte(unsigned char *pos);
 void eeprom_read_block (void *__dst, const void *__src, size_t __n);
 void eeprom_update_block (const void *__src, void *__dst, size_t __n);
 
-
-// ADC
+/**
+ * ADC
+ */
 
 #define HAL_ANALOG_SELECT(pin)
 
@@ -150,20 +145,13 @@ inline void HAL_adc_init(void) {}//todo
 #define HAL_START_ADC(pin)  HAL_adc_start_conversion(pin)
 #define HAL_READ_ADC        HAL_adc_result
 
-
 void HAL_adc_start_conversion(const uint8_t adc_pin);
-
 uint16_t HAL_adc_get_result(void);
-
-//
 uint16_t HAL_getAdcReading(uint8_t chan);
-
 void HAL_startAdcConversion(uint8_t chan);
 uint8_t HAL_pinToAdcChannel(int pin);
-
 uint16_t HAL_getAdcFreerun(uint8_t chan, bool wait_for_conversion = false);
 //uint16_t HAL_getAdcSuperSample(uint8_t chan);
-
 void HAL_enable_AdcFreerun(void);
 //void HAL_disable_AdcFreerun(uint8_t chan);
 
@@ -171,9 +159,4 @@ void HAL_enable_AdcFreerun(void);
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)
 
-// --------------------------------------------------------------------------
-//
-// --------------------------------------------------------------------------
-
 #endif // _HAL_DUE_H
-

Marlin/src/HAL/HAL_DUE/InterruptVectors_Due.cpp

@@ -0,0 +1,95 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * InterruptVectors_Due.cpp - This module relocates the Interrupt vector table to SRAM,
+ *  allowing to register new interrupt handlers at runtime. Specially valuable and needed
+ * because Arduino runtime allocates some interrupt handlers that we NEED to override to
+ * properly support extended functionality, as for example, USB host or USB device (MSD, MTP)
+ * and custom serial port handlers, and we don't actually want to modify and/or recompile the
+ * Arduino runtime. We just want to run as much as possible on Stock Arduino
+ *
+ * Copyright (c) 2017 Eduardo José Tagle. All right reserved
+ */
+#ifdef ARDUINO_ARCH_SAM
+
+#include "HAL_Due.h"
+#include "InterruptVectors_Due.h"
+
+/* The relocated Exception/Interrupt Table - Must be aligned to 128bytes,
+   as bits 0-6 on VTOR register are reserved and must be set to 0 */
+__attribute__ ((aligned(128)))
+static DeviceVectors ram_tab = { NULL };
+
+/**
+ * This function checks if the exception/interrupt table is already in SRAM or not.
+ * If it is not, then it copies the ROM table to the SRAM and relocates the table
+ * by reprogramming the NVIC registers
+ */
+static pfnISR_Handler* get_relocated_table_addr(void) {
+  // Get the address of the interrupt/exception table
+  uint32_t isrtab = SCB->VTOR;
+
+  // If already relocated, we are done!
+  if (isrtab >= IRAM0_ADDR)
+    return (pfnISR_Handler*)isrtab;
+
+  // Get the address of the table stored in FLASH
+  const pfnISR_Handler* romtab = (const pfnISR_Handler*)isrtab;
+
+  // Copy it to SRAM
+  memcpy(&ram_tab, romtab, sizeof(ram_tab));
+
+  // Disable global interrupts
+  CRITICAL_SECTION_START;
+
+  // Set the vector table base address to the SRAM copy
+  SCB->VTOR = (uint32_t)(&ram_tab);
+
+  // Reenable interrupts
+  CRITICAL_SECTION_END;
+
+  // Return the address of the table
+  return (pfnISR_Handler*)(&ram_tab);
+}
+
+pfnISR_Handler install_isr(IRQn_Type irq, pfnISR_Handler newHandler) {
+  // Get the address of the relocated table
+  const pfnISR_Handler *isrtab = get_relocated_table_addr();
+
+  // Disable global interrupts
+  CRITICAL_SECTION_START;
+
+  // Get the original handler
+  pfnISR_Handler oldHandler = isrtab[irq + 16];
+
+  // Install the new one
+  isrtab[irq + 16] = newHandler;
+
+  // Reenable interrupts
+  CRITICAL_SECTION_END;
+
+  // Return the original one
+  return oldHandler;
+}
+
+#endif

Marlin/src/HAL/HAL_DUE/InterruptVectors_Due.h

@@ -0,0 +1,52 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * InterruptVectors_Due.h
+ *
+ * Copyright (c) 2017 Eduardo José Tagle. All right reserved
+ *
+ * This module relocates the Interrupt vector table to SRAM, allowing new
+ * interrupt handlers to be added at runtime. This is required because the
+ * Arduino runtime steals interrupt handlers that Marlin MUST use to support
+ * extended functionality such as USB hosts and USB devices (MSD, MTP) and
+ * custom serial port handlers. Rather than modifying and/or recompiling the
+ * Arduino runtime, We just want to run as much as possible on Stock Arduino.
+ *
+ * Copyright (c) 2017 Eduardo José Tagle. All right reserved
+ */
+
+#ifndef INTERRUPTVECTORS_DUE_H
+#define INTERRUPTVECTORS_DUE_H
+
+#include "../../inc/MarlinConfig.h"
+
+#ifdef ARDUINO_ARCH_SAM
+
+// ISR handler type
+typedef void (*pfnISR_Handler)(void);
+
+// Install a new interrupt vector handler for the given irq, returning the old one
+pfnISR_Handler install_isr(IRQn_Type irq, pfnISR_Handler newHandler);
+
+#endif // ARDUINO_ARCH_SAM
+#endif // INTERRUPTVECTORS_DUE_H

Marlin/src/HAL/HAL_DUE/MarlinSerial_Due.cpp

@@ -0,0 +1,680 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * MarlinSerial_Due.cpp - Hardware serial library for Arduino DUE
+ * Copyright (c) 2017 Eduardo José Tagle. All right reserved
+ * Based on MarlinSerial for AVR, copyright (c) 2006 Nicholas Zambetti.  All right reserved.
+ */
+#ifdef ARDUINO_ARCH_SAM
+
+#include "../../inc/MarlinConfig.h"
+
+#include "MarlinSerial_Due.h"
+#include "InterruptVectors_Due.h"
+#include "../../Marlin.h"
+
+// Based on selected port, use the proper configuration
+#if SERIAL_PORT == 0
+  #define HWUART UART
+  #define HWUART_IRQ UART_IRQn
+  #define HWUART_IRQ_ID ID_UART
+#elif SERIAL_PORT == 1
+  #define HWUART USART0
+  #define HWUART_IRQ USART0_IRQn
+  #define HWUART_IRQ_ID ID_USART0
+#elif SERIAL_PORT == 2
+  #define HWUART USART1
+  #define HWUART_IRQ USART1_IRQn
+  #define HWUART_IRQ_ID ID_USART1
+#elif SERIAL_PORT == 3
+  #define HWUART USART3
+  #define HWUART_IRQ USART3_IRQn
+  #define HWUART_IRQ_ID ID_USART3
+#endif
+
+struct ring_buffer_r {
+  unsigned char buffer[RX_BUFFER_SIZE];
+  volatile ring_buffer_pos_t head, tail;
+};
+
+#if TX_BUFFER_SIZE > 0
+  struct ring_buffer_t {
+    unsigned char buffer[TX_BUFFER_SIZE];
+    volatile uint8_t head, tail;
+  };
+#endif
+
+ring_buffer_r rx_buffer = { { 0 }, 0, 0 };
+#if TX_BUFFER_SIZE > 0
+  ring_buffer_t tx_buffer = { { 0 }, 0, 0 };
+  static bool _written;
+#endif
+
+#if ENABLED(SERIAL_XON_XOFF)
+  constexpr uint8_t XON_XOFF_CHAR_SENT = 0x80;  // XON / XOFF Character was sent
+  constexpr uint8_t XON_XOFF_CHAR_MASK = 0x1F;  // XON / XOFF character to send
+  // XON / XOFF character definitions
+  constexpr uint8_t XON_CHAR  = 17;
+  constexpr uint8_t XOFF_CHAR = 19;
+  uint8_t xon_xoff_state = XON_XOFF_CHAR_SENT | XON_CHAR;
+
+  // Validate that RX buffer size is at least 4096 bytes- According to several experiments, on
+  // the original Arduino Due that uses a ATmega16U2 as USB to serial bridge, due to the introduced
+  // latencies, at least 2959 bytes of RX buffering (when transmitting at 250kbits/s) are required
+  // to avoid overflows.
+
+  #if RX_BUFFER_SIZE < 4096
+    #error Arduino DUE requires at least 4096 bytes of RX buffer to avoid buffer overflows when using XON/XOFF handshake
+  #endif
+#endif
+
+#if ENABLED(SERIAL_STATS_DROPPED_RX)
+  uint8_t rx_dropped_bytes = 0;
+#endif
+
+#if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
+  ring_buffer_pos_t rx_max_enqueued = 0;
+#endif
+
+// A SW memory barrier, to ensure GCC does not overoptimize loops
+#define sw_barrier() asm volatile("": : :"memory");
+
+#if ENABLED(EMERGENCY_PARSER)
+
+  #include "../../module/stepper.h"
+
+  // Currently looking for: M108, M112, M410
+  // If you alter the parser please don't forget to update the capabilities in Conditionals_post.h
+
+  FORCE_INLINE void emergency_parser(const uint8_t c) {
+
+    static e_parser_state state = state_RESET;
+
+    switch (state) {
+    case state_RESET:
+      switch (c) {
+        case ' ': break;
+        case 'N': state = state_N;      break;
+        case 'M': state = state_M;      break;
+        default: state = state_IGNORE;
+      }
+      break;
+
+    case state_N:
+      switch (c) {
+        case '0': case '1': case '2':
+        case '3': case '4': case '5':
+        case '6': case '7': case '8':
+        case '9': case '-': case ' ':   break;
+        case 'M': state = state_M;      break;
+        default:  state = state_IGNORE;
+      }
+      break;
+
+    case state_M:
+      switch (c) {
+        case ' ': break;
+        case '1': state = state_M1;     break;
+        case '4': state = state_M4;     break;
+        default: state = state_IGNORE;
+      }
+      break;
+
+    case state_M1:
+      switch (c) {
+        case '0': state = state_M10;    break;
+        case '1': state = state_M11;    break;
+        default: state = state_IGNORE;
+      }
+      break;
+
+    case state_M10:
+      state = (c == '8') ? state_M108 : state_IGNORE;
+      break;
+
+    case state_M11:
+      state = (c == '2') ? state_M112 : state_IGNORE;
+      break;
+
+    case state_M4:
+      state = (c == '1') ? state_M41 : state_IGNORE;
+      break;
+
+    case state_M41:
+      state = (c == '0') ? state_M410 : state_IGNORE;
+      break;
+
+    case state_IGNORE:
+      if (c == '\n') state = state_RESET;
+      break;
+
+    default:
+      if (c == '\n') {
+        switch (state) {
+          case state_M108:
+          wait_for_user = wait_for_heatup = false;
+          break;
+          case state_M112:
+          kill(PSTR(MSG_KILLED));
+          break;
+          case state_M410:
+          quickstop_stepper();
+          break;
+          default:
+          break;
+        }
+        state = state_RESET;
+      }
+    }
+  }
+
+#endif // EMERGENCY_PARSER
+
+FORCE_INLINE void store_rxd_char() {
+
+  const ring_buffer_pos_t h = rx_buffer.head,
+                          i = (ring_buffer_pos_t)(h + 1) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
+
+    // Read the character
+  const uint8_t c = HWUART->UART_RHR;
+
+  // If the character is to be stored at the index just before the tail
+  // (such that the head would advance to the current tail), the buffer is
+  // critical, so don't write the character or advance the head.
+  if (i != rx_buffer.tail) {
+    rx_buffer.buffer[h] = c;
+    rx_buffer.head = i;
+  }
+  #if ENABLED(SERIAL_STATS_DROPPED_RX)
+    else if (!++rx_dropped_bytes) ++rx_dropped_bytes;
+  #endif
+
+#if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
+  // calculate count of bytes stored into the RX buffer
+  ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
+  // Keep track of the maximum count of enqueued bytes
+  NOLESS(rx_max_enqueued, rx_count);
+#endif
+
+#if ENABLED(SERIAL_XON_XOFF)
+
+  // for high speed transfers, we can use XON/XOFF protocol to do
+  // software handshake and avoid overruns.
+  if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XON_CHAR) {
+
+    // calculate count of bytes stored into the RX buffer
+    ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
+
+    // if we are above 12.5% of RX buffer capacity, send XOFF before
+    // we run out of RX buffer space .. We need 325 bytes @ 250kbits/s to
+    // let the host react and stop sending bytes. This translates to 13mS
+    // propagation time.
+    if (rx_count >= (RX_BUFFER_SIZE) / 8) {
+      // If TX interrupts are disabled and data register is empty,
+      // just write the byte to the data register and be done. This
+      // shortcut helps significantly improve the effective datarate
+      // at high (>500kbit/s) bitrates, where interrupt overhead
+      // becomes a slowdown.
+      if (!(HWUART->UART_IMR & UART_IMR_TXRDY) && (HWUART->UART_SR & UART_SR_TXRDY)) {
+        // Send an XOFF character
+        HWUART->UART_THR = XOFF_CHAR;
+
+        // And remember it was sent
+        xon_xoff_state = XOFF_CHAR | XON_XOFF_CHAR_SENT;
+      }
+      else {
+        // TX interrupts disabled, but buffer still not empty ... or
+        // TX interrupts enabled. Reenable TX ints and schedule XOFF
+        // character to be sent
+        #if TX_BUFFER_SIZE > 0
+          HWUART->UART_IER = UART_IER_TXRDY;
+          xon_xoff_state = XOFF_CHAR;
+        #else
+          // We are not using TX interrupts, we will have to send this manually
+          while (!(HWUART->UART_SR & UART_SR_TXRDY)) { sw_barrier(); };
+          HWUART->UART_THR = XOFF_CHAR;
+          // And remember we already sent it
+          xon_xoff_state = XOFF_CHAR | XON_XOFF_CHAR_SENT;
+        #endif
+      }
+    }
+  }
+#endif // SERIAL_XON_XOFF
+
+#if ENABLED(EMERGENCY_PARSER)
+  emergency_parser(c);
+#endif
+}
+
+#if TX_BUFFER_SIZE > 0
+
+  FORCE_INLINE void _tx_thr_empty_irq(void) {
+    // If interrupts are enabled, there must be more data in the output
+    // buffer.
+
+    #if ENABLED(SERIAL_XON_XOFF)
+      // Do a priority insertion of an XON/XOFF char, if needed.
+      const uint8_t state = xon_xoff_state;
+      if (!(state & XON_XOFF_CHAR_SENT)) {
+        HWUART->UART_THR = state & XON_XOFF_CHAR_MASK;
+        xon_xoff_state = state | XON_XOFF_CHAR_SENT;
+      }
+      else
+    #endif
+      { // Send the next byte
+        const uint8_t t = tx_buffer.tail, c = tx_buffer.buffer[t];
+        tx_buffer.tail = (t + 1) & (TX_BUFFER_SIZE - 1);
+        HWUART->UART_THR = c;
+      }
+
+    // Disable interrupts if the buffer is empty
+    if (tx_buffer.head == tx_buffer.tail)
+      HWUART->UART_IDR = UART_IDR_TXRDY;
+  }
+
+#endif // TX_BUFFER_SIZE
+
+static void UART_ISR(void) {
+  uint32_t status = HWUART->UART_SR;
+
+  // Did we receive data?
+  if (status & UART_SR_RXRDY)
+    store_rxd_char();
+
+  #if TX_BUFFER_SIZE > 0
+    // Do we have something to send, and TX interrupts are enabled (meaning something to send) ?
+    if ((status & UART_SR_TXRDY) && (HWUART->UART_IMR & UART_IMR_TXRDY))
+      _tx_thr_empty_irq();
+  #endif
+
+  // Acknowledge errors
+  if ((status & UART_SR_OVRE) || (status & UART_SR_FRAME)) {
+    // TODO: error reporting outside ISR
+    HWUART->UART_CR = UART_CR_RSTSTA;
+  }
+}
+
+// Public Methods
+
+void MarlinSerial::begin(const long baud_setting) {
+
+  // Disable UART interrupt in NVIC
+  NVIC_DisableIRQ( HWUART_IRQ );
+
+  // Disable clock
+  pmc_disable_periph_clk( HWUART_IRQ_ID );
+
+  // Configure PMC
+  pmc_enable_periph_clk( HWUART_IRQ_ID );
+
+  // Disable PDC channel
+  HWUART->UART_PTCR = UART_PTCR_RXTDIS | UART_PTCR_TXTDIS;
+
+  // Reset and disable receiver and transmitter
+  HWUART->UART_CR = UART_CR_RSTRX | UART_CR_RSTTX | UART_CR_RXDIS | UART_CR_TXDIS;
+
+  // Configure mode: 8bit, No parity, 1 bit stop
+  HWUART->UART_MR = UART_MR_CHMODE_NORMAL | US_MR_CHRL_8_BIT | US_MR_NBSTOP_1_BIT | UART_MR_PAR_NO;
+
+  // Configure baudrate (asynchronous, no oversampling)
+  HWUART->UART_BRGR = (SystemCoreClock / (baud_setting << 4));
+
+  // Configure interrupts
+  HWUART->UART_IDR = 0xFFFFFFFF;
+  HWUART->UART_IER = UART_IER_RXRDY | UART_IER_OVRE | UART_IER_FRAME;
+
+  // Install interrupt handler
+  install_isr(HWUART_IRQ, UART_ISR);
+
+  // Enable UART interrupt in NVIC
+  NVIC_EnableIRQ(HWUART_IRQ);
+
+  // Enable receiver and transmitter
+  HWUART->UART_CR = UART_CR_RXEN | UART_CR_TXEN;
+
+  #if TX_BUFFER_SIZE > 0
+    _written = false;
+  #endif
+}
+
+void MarlinSerial::end() {
+  // Disable UART interrupt in NVIC
+  NVIC_DisableIRQ( HWUART_IRQ );
+
+  pmc_disable_periph_clk( HWUART_IRQ_ID );
+}
+
+void MarlinSerial::checkRx(void) {
+  if (HWUART->UART_SR & UART_SR_RXRDY) {
+    CRITICAL_SECTION_START;
+    store_rxd_char();
+    CRITICAL_SECTION_END;
+  }
+}
+
+int MarlinSerial::peek(void) {
+  CRITICAL_SECTION_START;
+  const int v = rx_buffer.head == rx_buffer.tail ? -1 : rx_buffer.buffer[rx_buffer.tail];
+  CRITICAL_SECTION_END;
+  return v;
+}
+
+int MarlinSerial::read(void) {
+  int v;
+  CRITICAL_SECTION_START;
+  const ring_buffer_pos_t t = rx_buffer.tail;
+  if (rx_buffer.head == t)
+    v = -1;
+  else {
+    v = rx_buffer.buffer[t];
+    rx_buffer.tail = (ring_buffer_pos_t)(t + 1) & (RX_BUFFER_SIZE - 1);
+
+  #if ENABLED(SERIAL_XON_XOFF)
+    if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XOFF_CHAR) {
+      // Get count of bytes in the RX buffer
+      ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
+      // When below 10% of RX buffer capacity, send XON before
+      // running out of RX buffer bytes
+      if (rx_count < (RX_BUFFER_SIZE) / 10) {
+        xon_xoff_state = XON_CHAR | XON_XOFF_CHAR_SENT;
+        CRITICAL_SECTION_END;       // End critical section before returning!
+        writeNoHandshake(XON_CHAR);
+        return v;
+      }
+    }
+  #endif
+  }
+  CRITICAL_SECTION_END;
+  return v;
+}
+
+ring_buffer_pos_t MarlinSerial::available(void) {
+  CRITICAL_SECTION_START;
+  const ring_buffer_pos_t h = rx_buffer.head, t = rx_buffer.tail;
+  CRITICAL_SECTION_END;
+  return (ring_buffer_pos_t)(RX_BUFFER_SIZE + h - t) & (RX_BUFFER_SIZE - 1);
+}
+
+void MarlinSerial::flush(void) {
+  // Don't change this order of operations. If the RX interrupt occurs between
+  // reading rx_buffer_head and updating rx_buffer_tail, the previous rx_buffer_head
+  // may be written to rx_buffer_tail, making the buffer appear full rather than empty.
+  CRITICAL_SECTION_START;
+  rx_buffer.head = rx_buffer.tail;
+  CRITICAL_SECTION_END;
+
+#if ENABLED(SERIAL_XON_XOFF)
+  if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XOFF_CHAR) {
+    xon_xoff_state = XON_CHAR | XON_XOFF_CHAR_SENT;
+    writeNoHandshake(XON_CHAR);
+  }
+#endif
+}
+
+#if TX_BUFFER_SIZE > 0
+  uint8_t MarlinSerial::availableForWrite(void) {
+    CRITICAL_SECTION_START;
+    const uint8_t h = tx_buffer.head, t = tx_buffer.tail;
+    CRITICAL_SECTION_END;
+    return (uint8_t)(TX_BUFFER_SIZE + h - t) & (TX_BUFFER_SIZE - 1);
+  }
+
+  void MarlinSerial::write(const uint8_t c) {
+    #if ENABLED(SERIAL_XON_XOFF)
+      const uint8_t state = xon_xoff_state;
+      if (!(state & XON_XOFF_CHAR_SENT)) {
+        // Send 2 chars: XON/XOFF, then a user-specified char
+        writeNoHandshake(state & XON_XOFF_CHAR_MASK);
+        xon_xoff_state = state | XON_XOFF_CHAR_SENT;
+      }
+    #endif
+    writeNoHandshake(c);
+  }
+
+  void MarlinSerial::writeNoHandshake(const uint8_t c) {
+    _written = true;
+    CRITICAL_SECTION_START;
+    bool emty = (tx_buffer.head == tx_buffer.tail);
+    CRITICAL_SECTION_END;
+    // If the buffer and the data register is empty, just write the byte
+    // to the data register and be done. This shortcut helps
+    // significantly improve the effective datarate at high (>
+    // 500kbit/s) bitrates, where interrupt overhead becomes a slowdown.
+    if (emty && (HWUART->UART_SR & UART_SR_TXRDY)) {
+      CRITICAL_SECTION_START;
+        HWUART->UART_THR = c;
+        HWUART->UART_IER = UART_IER_TXRDY;
+      CRITICAL_SECTION_END;
+      return;
+    }
+    const uint8_t i = (tx_buffer.head + 1) & (TX_BUFFER_SIZE - 1);
+
+    // If the output buffer is full, there's nothing for it other than to
+    // wait for the interrupt handler to empty it a bit
+    while (i == tx_buffer.tail) {
+      if (__get_PRIMASK()) {
+        // Interrupts are disabled, so we'll have to poll the data
+        // register empty flag ourselves. If it is set, pretend an
+        // interrupt has happened and call the handler to free up
+        // space for us.
+        if (HWUART->UART_SR & UART_SR_TXRDY)
+          _tx_thr_empty_irq();
+      }
+      else {
+        // nop, the interrupt handler will free up space for us
+      }
+      sw_barrier();
+    }
+
+    tx_buffer.buffer[tx_buffer.head] = c;
+    { CRITICAL_SECTION_START;
+        tx_buffer.head = i;
+        HWUART->UART_IER = UART_IER_TXRDY;
+      CRITICAL_SECTION_END;
+    }
+    return;
+  }
+
+  void MarlinSerial::flushTX(void) {
+    // TX
+    // If we have never written a byte, no need to flush.
+    if (!_written)
+      return;
+
+    while ((HWUART->UART_IMR & UART_IMR_TXRDY) || !(HWUART->UART_SR & UART_SR_TXEMPTY)) {
+      if (__get_PRIMASK())
+        if ((HWUART->UART_SR & UART_SR_TXRDY))
+          _tx_thr_empty_irq();
+      sw_barrier();
+    }
+    // If we get here, nothing is queued anymore (TX interrupts are disabled) and
+    // the hardware finished tranmission (TXEMPTY is set).
+  }
+
+#else // TX_BUFFER_SIZE == 0
+
+  void MarlinSerial::write(const uint8_t c) {
+    #if ENABLED(SERIAL_XON_XOFF)
+      // Do a priority insertion of an XON/XOFF char, if needed.
+      const uint8_t state = xon_xoff_state;
+      if (!(state & XON_XOFF_CHAR_SENT)) {
+        writeNoHandshake(state & XON_XOFF_CHAR_MASK);
+        xon_xoff_state = state | XON_XOFF_CHAR_SENT;
+      }
+    #endif
+    writeNoHandshake(c);
+  }
+
+  void MarlinSerial::writeNoHandshake(const uint8_t c) {
+    while (!(HWUART->UART_SR & UART_SR_TXRDY)) { sw_barrier(); };
+    HWUART->UART_THR = c;
+  }
+
+#endif // TX_BUFFER_SIZE == 0
+
+/**
+* Imports from print.h
+*/
+
+void MarlinSerial::print(char c, int base) {
+  print((long)c, base);
+}
+
+void MarlinSerial::print(unsigned char b, int base) {
+  print((unsigned long)b, base);
+}
+
+void MarlinSerial::print(int n, int base) {
+  print((long)n, base);
+}
+
+void MarlinSerial::print(unsigned int n, int base) {
+  print((unsigned long)n, base);
+}
+
+void MarlinSerial::print(long n, int base) {
+  if (base == 0)
+    write(n);
+  else if (base == 10) {
+    if (n < 0) {
+      print('-');
+      n = -n;
+    }
+    printNumber(n, 10);
+  }
+  else
+    printNumber(n, base);
+}
+
+void MarlinSerial::print(unsigned long n, int base) {
+  if (base == 0) write(n);
+  else printNumber(n, base);
+}
+
+void MarlinSerial::print(double n, int digits) {
+  printFloat(n, digits);
+}
+
+void MarlinSerial::println(void) {
+  print('\r');
+  print('\n');
+}
+
+void MarlinSerial::println(const String& s) {
+  print(s);
+  println();
+}
+
+void MarlinSerial::println(const char c[]) {
+  print(c);
+  println();
+}
+
+void MarlinSerial::println(char c, int base) {
+  print(c, base);
+  println();
+}
+
+void MarlinSerial::println(unsigned char b, int base) {
+  print(b, base);
+  println();
+}
+
+void MarlinSerial::println(int n, int base) {
+  print(n, base);
+  println();
+}
+
+void MarlinSerial::println(unsigned int n, int base) {
+  print(n, base);
+  println();
+}
+
+void MarlinSerial::println(long n, int base) {
+  print(n, base);
+  println();
+}
+
+void MarlinSerial::println(unsigned long n, int base) {
+  print(n, base);
+  println();
+}
+
+void MarlinSerial::println(double n, int digits) {
+  print(n, digits);
+  println();
+}
+
+// Private Methods
+
+void MarlinSerial::printNumber(unsigned long n, uint8_t base) {
+  if (n) {
+    unsigned char buf[8 * sizeof(long)]; // Enough space for base 2
+    int8_t i = 0;
+    while (n) {
+      buf[i++] = n % base;
+      n /= base;
+    }
+    while (i--)
+      print((char)(buf[i] + (buf[i] < 10 ? '0' : 'A' - 10)));
+  }
+  else
+    print('0');
+}
+
+void MarlinSerial::printFloat(double number, uint8_t digits) {
+  // Handle negative numbers
+  if (number < 0.0) {
+    print('-');
+    number = -number;
+  }
+
+  // Round correctly so that print(1.999, 2) prints as "2.00"
+  double rounding = 0.5;
+  for (uint8_t i = 0; i < digits; ++i)
+    rounding *= 0.1;
+
+  number += rounding;
+
+  // Extract the integer part of the number and print it
+  unsigned long int_part = (unsigned long)number;
+  double remainder = number - (double)int_part;
+  print(int_part);
+
+  // Print the decimal point, but only if there are digits beyond
+  if (digits) {
+    print('.');
+    // Extract digits from the remainder one at a time
+    while (digits--) {
+      remainder *= 10.0;
+      int toPrint = int(remainder);
+      print(toPrint);
+      remainder -= toPrint;
+    }
+  }
+}
+
+// Preinstantiate
+MarlinSerial customizedSerial;
+
+#endif // ARDUINO_ARCH_SAM

Marlin/src/HAL/HAL_DUE/MarlinSerial_Due.h

@@ -0,0 +1,142 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * MarlinSerial_Due.h - Hardware serial library for Arduino DUE
+ * Copyright (c) 2017 Eduardo José Tagle. All right reserved
+ * Based on MarlinSerial for AVR, copyright (c) 2006 Nicholas Zambetti.  All right reserved.
+ */
+
+#ifndef MARLINSERIAL_DUE_H
+#define MARLINSERIAL_DUE_H
+
+#include "../../inc/MarlinConfig.h"
+
+#include <WString.h>
+
+#ifndef SERIAL_PORT
+  #define SERIAL_PORT 0
+#endif
+
+#define DEC 10
+#define HEX 16
+#define OCT 8
+#define BIN 2
+#define BYTE 0
+
+// Define constants and variables for buffering incoming serial data.  We're
+// using a ring buffer (I think), in which rx_buffer_head is the index of the
+// location to which to write the next incoming character and rx_buffer_tail
+// is the index of the location from which to read.
+// 256 is the max limit due to uint8_t head and tail. Use only powers of 2. (...,16,32,64,128,256)
+#ifndef RX_BUFFER_SIZE
+  #define RX_BUFFER_SIZE 128
+#endif
+#ifndef TX_BUFFER_SIZE
+  #define TX_BUFFER_SIZE 32
+#endif
+
+#if ENABLED(SERIAL_XON_XOFF) && RX_BUFFER_SIZE < 1024
+  #error "XON/XOFF requires RX_BUFFER_SIZE >= 1024 for reliable transfers without drops."
+#endif
+
+#if !IS_POWER_OF_2(RX_BUFFER_SIZE) || RX_BUFFER_SIZE < 2
+  #error "RX_BUFFER_SIZE must be a power of 2 greater than 1."
+#endif
+
+#if TX_BUFFER_SIZE && (TX_BUFFER_SIZE < 2 || TX_BUFFER_SIZE > 256 || !IS_POWER_OF_2(TX_BUFFER_SIZE))
+  #error "TX_BUFFER_SIZE must be 0 or a power of 2 greater than 1."
+#endif
+
+#if RX_BUFFER_SIZE > 256
+  typedef uint16_t ring_buffer_pos_t;
+#else
+  typedef uint8_t ring_buffer_pos_t;
+#endif
+
+#if ENABLED(SERIAL_STATS_DROPPED_RX)
+  extern uint8_t rx_dropped_bytes;
+#endif
+
+#if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
+  extern ring_buffer_pos_t rx_max_enqueued;
+#endif
+
+class MarlinSerial {
+
+public:
+  MarlinSerial() {};
+  static void begin(const long);
+  static void end();
+  static int peek(void);
+  static int read(void);
+  static void flush(void);
+  static ring_buffer_pos_t available(void);
+  static void checkRx(void);
+  static void write(const uint8_t c);
+  #if TX_BUFFER_SIZE > 0
+    static uint8_t availableForWrite(void);
+    static void flushTX(void);
+  #endif
+  static void writeNoHandshake(const uint8_t c);
+
+  #if ENABLED(SERIAL_STATS_DROPPED_RX)
+    FORCE_INLINE static uint32_t dropped() { return rx_dropped_bytes; }
+  #endif
+
+  #if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
+    FORCE_INLINE static ring_buffer_pos_t rxMaxEnqueued() { return rx_max_enqueued; }
+  #endif
+
+  static FORCE_INLINE void write(const char* str) { while (*str) write(*str++); }
+  static FORCE_INLINE void write(const uint8_t* buffer, size_t size) { while (size--) write(*buffer++); }
+  static FORCE_INLINE void print(const String& s) { for (int i = 0; i < (int)s.length(); i++) write(s[i]); }
+  static FORCE_INLINE void print(const char* str) { write(str); }
+
+  static void print(char, int = BYTE);
+  static void print(unsigned char, int = BYTE);
+  static void print(int, int = DEC);
+  static void print(unsigned int, int = DEC);
+  static void print(long, int = DEC);
+  static void print(unsigned long, int = DEC);
+  static void print(double, int = 2);
+
+  static void println(const String& s);
+  static void println(const char[]);
+  static void println(char, int = BYTE);
+  static void println(unsigned char, int = BYTE);
+  static void println(int, int = DEC);
+  static void println(unsigned int, int = DEC);
+  static void println(long, int = DEC);
+  static void println(unsigned long, int = DEC);
+  static void println(double, int = 2);
+  static void println(void);
+  operator bool() { return true; }
+
+private:
+  static void printNumber(unsigned long, const uint8_t);
+  static void printFloat(double, uint8_t);
+};
+
+extern MarlinSerial customizedSerial;
+
+#endif // MARLINSERIAL_DUE_H

Marlin/src/core/serial.h

@@ -25,24 +25,10 @@
 
 #include "../inc/MarlinConfig.h"
 
-//todo: HAL: breaks encapsulation
-// For AVR only, define a serial interface based on configuration
-#ifdef __AVR__
-  #ifdef USBCON
-    #include "HardwareSerial.h"
-    #if ENABLED(BLUETOOTH)
-      #define MYSERIAL bluetoothSerial
-    #else
-      #define MYSERIAL Serial
-    #endif // BLUETOOTH
-  #else
-    #include "../HAL/HAL_AVR/MarlinSerial.h"
-    #define MYSERIAL customizedSerial
-  #endif
+#if HAS_ABL && ENABLED(DEBUG_LEVELING_FEATURE)
+  #include "../libs/vector_3.h"
 #endif
 
-#include "../libs/vector_3.h"
-
 /**
  * Define debug bit-masks
  */
@@ -58,6 +44,27 @@ enum DebugFlags {
   DEBUG_ALL           = 0xFF
 };
 
+//todo: HAL: breaks encapsulation
+// For AVR only, define a serial interface based on configuration
+#ifdef __AVR__
+  #ifdef USBCON
+    #include "HardwareSerial.h"
+    #if ENABLED(BLUETOOTH)
+      #define MYSERIAL bluetoothSerial
+    #else
+      #define MYSERIAL Serial
+    #endif // BLUETOOTH
+  #else
+    #include "../HAL/HAL_AVR/MarlinSerial.h"
+    #define MYSERIAL customizedSerial
+  #endif
+#endif
+
+#ifdef ARDUINO_ARCH_SAM
+  // To pull the Serial port definitions and overrides
+  #include "../HAL/HAL_DUE/MarlinSerial_Due.h"
+#endif
+
 extern uint8_t marlin_debug_flags;
 #define DEBUGGING(F) (marlin_debug_flags & (DEBUG_## F))
 

frameworks/CMSIS/LPC1768/driver/debug_frmwrk.c

@@ -1,11 +1,11 @@
 /**********************************************************************
-* $Id$		debug_frmwrk.c				2010-05-21
-*//**
-* @file		debug_frmwrk.c
-* @brief	Contains some utilities that used for debugging through UART
-* @version	2.0
-* @date		21. May. 2010
-* @author	NXP MCU SW Application Team
+* $Id$    debug_frmwrk.c        2010-05-21
+*
+* @file   debug_frmwrk.c
+* @brief  Contains some utilities that used for debugging through UART
+* @version  2.0
+* @date   21. May. 2010
+* @author NXP MCU SW Application Team
 *
 * Copyright(C) 2010, NXP Semiconductor
 * All rights reserved.
@@ -37,12 +37,13 @@
  * otherwise the default FW library configuration file must be included instead
  */
 #ifdef __BUILD_WITH_EXAMPLE__
-#include "lpc17xx_libcfg.h"
+  #include "lpc17xx_libcfg.h"
 #else
-#include "lpc17xx_libcfg_default.h"
-#endif /* __BUILD_WITH_EXAMPLE__ */
+  #include "lpc17xx_libcfg_default.h"
+#endif
 
 #ifdef _DBGFWK
+
 /* Debug framework */
 static Bool debug_frmwrk_initialized = FALSE;
 
@@ -59,284 +60,247 @@ uint8_t (*_db_get_char)(LPC_UART_TypeDef *UARTx) = UARTGetChar;
 
 
 /*********************************************************************//**
- * @brief		Puts a character to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	ch		Character to put
- * @return		None
+ * @brief   Puts a character to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] ch    Character to put
+ * @return    None
  **********************************************************************/
-void UARTPutChar (LPC_UART_TypeDef *UARTx, uint8_t ch)
-{
+void UARTPutChar(LPC_UART_TypeDef *UARTx, uint8_t ch) {
   if (debug_frmwrk_initialized)
-	  UART_Send(UARTx, &ch, 1, BLOCKING);
+    UART_Send(UARTx, &ch, 1, BLOCKING);
 }
 
-
 /*********************************************************************//**
- * @brief		Get a character to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @return		character value that returned
+ * @brief   Get a character to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @return    character value that returned
  **********************************************************************/
-uint8_t UARTGetChar (LPC_UART_TypeDef *UARTx)
-{
+uint8_t UARTGetChar(LPC_UART_TypeDef *UARTx) {
   uint8_t tmp = 0;
-  
+
   if (debug_frmwrk_initialized)
     UART_Receive(UARTx, &tmp, 1, BLOCKING);
-    
-	return(tmp);
-}
 
+  return(tmp);
+}
 
 /*********************************************************************//**
- * @brief		Puts a string to UART port
- * @param[in]	UARTx 	Pointer to UART peripheral
- * @param[in]	str 	string to put
- * @return		None
+ * @brief   Puts a string to UART port
+ * @param[in] UARTx   Pointer to UART peripheral
+ * @param[in] str   string to put
+ * @return    None
  **********************************************************************/
-void UARTPuts(LPC_UART_TypeDef *UARTx, const void *str)
-{
-  uint8_t *s = (uint8_t *) str;
-  
-  if (!debug_frmwrk_initialized)
-    return;
-
-	while (*s)
-	{
-		UARTPutChar(UARTx, *s++);
-	}
-}
+void UARTPuts(LPC_UART_TypeDef *UARTx, const void *str) {
+  if (!debug_frmwrk_initialized) return;
 
+  uint8_t *s = (uint8_t*)str;
+  while (*s) UARTPutChar(UARTx, *s++);
+}
 
 /*********************************************************************//**
- * @brief		Puts a string to UART port and print new line
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	str		String to put
- * @return		None
+ * @brief   Puts a string to UART port and print new line
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] str   String to put
+ * @return    None
  **********************************************************************/
-void UARTPuts_(LPC_UART_TypeDef *UARTx, const void *str)
-{
-  if (!debug_frmwrk_initialized)
-    return;
+void UARTPuts_(LPC_UART_TypeDef *UARTx, const void *str) {
+  if (!debug_frmwrk_initialized) return;
 
-	UARTPuts (UARTx, str);
-	UARTPuts (UARTx, "\n\r");
+  UARTPuts (UARTx, str);
+  UARTPuts (UARTx, "\n\r");
 }
 
-
 /*********************************************************************//**
- * @brief		Puts a decimal number to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	decnum	Decimal number (8-bit long)
- * @return		None
+ * @brief   Puts a decimal number to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] decnum  Decimal number (8-bit long)
+ * @return    None
  **********************************************************************/
-void UARTPutDec(LPC_UART_TypeDef *UARTx, uint8_t decnum)
-{
-  if (!debug_frmwrk_initialized)
-    return;
-
-	uint8_t c1=decnum%10;
-	uint8_t c2=(decnum/10)%10;
-	uint8_t c3=(decnum/100)%10;
-	UARTPutChar(UARTx, '0'+c3);
-	UARTPutChar(UARTx, '0'+c2);
-	UARTPutChar(UARTx, '0'+c1);
+void UARTPutDec(LPC_UART_TypeDef *UARTx, uint8_t decnum) {
+  if (!debug_frmwrk_initialized) return;
+
+  uint8_t c1 = decnum%10;
+  uint8_t c2 = (decnum /             10) % 10;
+  uint8_t c3 = (decnum /            100) % 10;
+  UARTPutChar(UARTx, '0'+c3);
+  UARTPutChar(UARTx, '0'+c2);
+  UARTPutChar(UARTx, '0'+c1);
 }
 
 /*********************************************************************//**
- * @brief		Puts a decimal number to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	decnum	Decimal number (8-bit long)
- * @return		None
+ * @brief   Puts a decimal number to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] decnum  Decimal number (8-bit long)
+ * @return    None
  **********************************************************************/
-void UARTPutDec16(LPC_UART_TypeDef *UARTx, uint16_t decnum)
-{  
-  if (!debug_frmwrk_initialized)
-    return;
-
-	uint8_t c1=decnum%10;
-	uint8_t c2=(decnum/10)%10;
-	uint8_t c3=(decnum/100)%10;
-	uint8_t c4=(decnum/1000)%10;
-	uint8_t c5=(decnum/10000)%10;
-	UARTPutChar(UARTx, '0'+c5);
-	UARTPutChar(UARTx, '0'+c4);
-	UARTPutChar(UARTx, '0'+c3);
-	UARTPutChar(UARTx, '0'+c2);
-	UARTPutChar(UARTx, '0'+c1);
+void UARTPutDec16(LPC_UART_TypeDef *UARTx, uint16_t decnum) {
+  if (!debug_frmwrk_initialized) return;
+
+  uint8_t c1 = decnum%10;
+  uint8_t c2 = (decnum /             10) % 10;
+  uint8_t c3 = (decnum /            100) % 10;
+  uint8_t c4 = (decnum /           1000) % 10;
+  uint8_t c5 = (decnum /          10000) % 10;
+  UARTPutChar(UARTx, '0'+c5);
+  UARTPutChar(UARTx, '0'+c4);
+  UARTPutChar(UARTx, '0'+c3);
+  UARTPutChar(UARTx, '0'+c2);
+  UARTPutChar(UARTx, '0'+c1);
 }
 
 /*********************************************************************//**
- * @brief		Puts a decimal number to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	decnum	Decimal number (8-bit long)
- * @return		None
+ * @brief   Puts a decimal number to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] decnum  Decimal number (8-bit long)
+ * @return    None
  **********************************************************************/
-void UARTPutDec32(LPC_UART_TypeDef *UARTx, uint32_t decnum)
-{
-  if (!debug_frmwrk_initialized)
-    return;
-
-	uint8_t c1=decnum%10;
-	uint8_t c2=(decnum/10)%10;
-	uint8_t c3=(decnum/100)%10;
-	uint8_t c4=(decnum/1000)%10;
-	uint8_t c5=(decnum/10000)%10;
-	uint8_t c6=(decnum/100000)%10;
-	uint8_t c7=(decnum/1000000)%10;
-	uint8_t c8=(decnum/10000000)%10;
-	uint8_t c9=(decnum/100000000)%10;
-	uint8_t c10=(decnum/1000000000)%10;
-	UARTPutChar(UARTx, '0'+c10);
-	UARTPutChar(UARTx, '0'+c9);
-	UARTPutChar(UARTx, '0'+c8);
-	UARTPutChar(UARTx, '0'+c7);
-	UARTPutChar(UARTx, '0'+c6);
-	UARTPutChar(UARTx, '0'+c5);
-	UARTPutChar(UARTx, '0'+c4);
-	UARTPutChar(UARTx, '0'+c3);
-	UARTPutChar(UARTx, '0'+c2);
-	UARTPutChar(UARTx, '0'+c1);
+void UARTPutDec32(LPC_UART_TypeDef *UARTx, uint32_t decnum) {
+  if (!debug_frmwrk_initialized) return;
+
+  const uint8_t  c1 =  decnum               % 10,
+                 c2 = (decnum /         10) % 10,
+                 c3 = (decnum /        100) % 10,
+                 c4 = (decnum /       1000) % 10,
+                 c5 = (decnum /      10000) % 10,
+                 c6 = (decnum /     100000) % 10,
+                 c7 = (decnum /    1000000) % 10,
+                 c8 = (decnum /   10000000) % 10,
+                 c9 = (decnum /  100000000) % 10,
+                c10 = (decnum / 1000000000) % 10;
+  UARTPutChar(UARTx, '0' + c10);
+  UARTPutChar(UARTx, '0' +  c9);
+  UARTPutChar(UARTx, '0' +  c8);
+  UARTPutChar(UARTx, '0' +  c7);
+  UARTPutChar(UARTx, '0' +  c6);
+  UARTPutChar(UARTx, '0' +  c5);
+  UARTPutChar(UARTx, '0' +  c4);
+  UARTPutChar(UARTx, '0' +  c3);
+  UARTPutChar(UARTx, '0' +  c2);
+  UARTPutChar(UARTx, '0' +  c1);
 }
 
 /*********************************************************************//**
- * @brief		Puts a hex number to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	hexnum	Hex number (8-bit long)
- * @return		None
+ * @brief   Puts a hex number to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] hexnum  Hex number (8-bit long)
+ * @return    None
  **********************************************************************/
-void UARTPutHex (LPC_UART_TypeDef *UARTx, uint8_t hexnum)
-{
-	uint8_t nibble, i;
-  
-  if (!debug_frmwrk_initialized)
-    return;
-
-	UARTPuts(UARTx, "0x");
-	i = 1;
-	do {
-		nibble = (hexnum >> (4*i)) & 0x0F;
-		UARTPutChar(UARTx, (nibble > 9) ? ('A' + nibble - 10) : ('0' + nibble));
-	} while (i--);
+void UARTPutHex(LPC_UART_TypeDef *UARTx, uint8_t hexnum) {
+  if (!debug_frmwrk_initialized) return;
+
+  UARTPuts(UARTx, "0x");
+  uint8_t nibble, i = 1;
+  do {
+    nibble = (hexnum >> (4 * i)) & 0x0F;
+    UARTPutChar(UARTx, (nibble > 9) ? ('A' + nibble - 10) : ('0' + nibble));
+  } while (i--);
 }
 
-
 /*********************************************************************//**
- * @brief		Puts a hex number to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	hexnum	Hex number (16-bit long)
- * @return		None
+ * @brief   Puts a hex number to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] hexnum  Hex number (16-bit long)
+ * @return    None
  **********************************************************************/
-void UARTPutHex16 (LPC_UART_TypeDef *UARTx, uint16_t hexnum)
-{
-	uint8_t nibble, i;
-  
-  if (!debug_frmwrk_initialized)
-    return;
-
-	UARTPuts(UARTx, "0x");
-	i = 3;
-	do {
-		nibble = (hexnum >> (4*i)) & 0x0F;
-		UARTPutChar(UARTx, (nibble > 9) ? ('A' + nibble - 10) : ('0' + nibble));
-	} while (i--);
+void UARTPutHex16(LPC_UART_TypeDef *UARTx, uint16_t hexnum) {
+  if (!debug_frmwrk_initialized) return;
+
+  UARTPuts(UARTx, "0x");
+  uint8_t nibble, i = 3;
+  do {
+    nibble = (hexnum >> (4 * i)) & 0x0F;
+    UARTPutChar(UARTx, (nibble > 9) ? ('A' + nibble - 10) : ('0' + nibble));
+  } while (i--);
 }
 
 /*********************************************************************//**
- * @brief		Puts a hex number to UART port
- * @param[in]	UARTx	Pointer to UART peripheral
- * @param[in]	hexnum	Hex number (32-bit long)
- * @return		None
+ * @brief   Puts a hex number to UART port
+ * @param[in] UARTx Pointer to UART peripheral
+ * @param[in] hexnum  Hex number (32-bit long)
+ * @return    None
  **********************************************************************/
-void UARTPutHex32 (LPC_UART_TypeDef *UARTx, uint32_t hexnum)
-{
-  uint8_t nibble, i;
-  
-  if (!debug_frmwrk_initialized)
-    return;
-
-	UARTPuts(UARTx, "0x");
-	i = 7;
-	do {
-		nibble = (hexnum >> (4*i)) & 0x0F;
-		UARTPutChar(UARTx, (nibble > 9) ? ('A' + nibble - 10) : ('0' + nibble));
-	} while (i--);
+void UARTPutHex32(LPC_UART_TypeDef *UARTx, uint32_t hexnum) {
+  if (!debug_frmwrk_initialized) return;
+
+  UARTPuts(UARTx, "0x");
+  uint8_t nibble, i = 7;
+  do {
+    nibble = (hexnum >> (4 * i)) & 0x0F;
+    UARTPutChar(UARTx, (nibble > 9) ? ('A' + nibble - 10) : ('0' + nibble));
+  } while (i--);
 }
 
-///*********************************************************************//**
-// * @brief		print function that supports format as same as printf()
-// * 				function of <stdio.h> library
-// * @param[in]	None
-// * @return		None
-// **********************************************************************/
-//void  _printf (const  char *format, ...)
-//{
-//    static  char  buffer[512 + 1];
-//            va_list     vArgs;
-//            char	*tmp;
-//    va_start(vArgs, format);
-//    vsprintf((char *)buffer, (char const *)format, vArgs);
-//    va_end(vArgs);
+/*********************************************************************//**
+ * @brief   print function that supports format as same as printf()
+ *        function of <stdio.h> library
+ * @param[in] None
+ * @return    None
+ **********************************************************************/
+//void  _printf (const  char *format, ...) {
+//  static  char  buffer[512 + 1];
+//          va_list     vArgs;
+//          char  *tmp;
+//  va_start(vArgs, format);
+//  vsprintf((char *)buffer, (char const *)format, vArgs);
+//  va_end(vArgs);
 //
-//    _DBG(buffer);
+//  _DBG(buffer);
 //}
 
 /*********************************************************************//**
- * @brief		Initialize Debug frame work through initializing UART port
- * @param[in]	None
- * @return		None
+ * @brief   Initialize Debug frame work through initializing UART port
+ * @param[in] None
+ * @return    None
  **********************************************************************/
-void debug_frmwrk_init(void)
-{
-	UART_CFG_Type UARTConfigStruct;
-	PINSEL_CFG_Type PinCfg;
-
-#if (USED_UART_DEBUG_PORT==0)
-	/*
-	 * Initialize UART0 pin connect
-	 */
-	PinCfg.Funcnum = 1;
-	PinCfg.OpenDrain = 0;
-	PinCfg.Pinmode = 0;
-	PinCfg.Pinnum = 2;
-	PinCfg.Portnum = 0;
-	PINSEL_ConfigPin(&PinCfg);
-	PinCfg.Pinnum = 3;
-	PINSEL_ConfigPin(&PinCfg);
-
-#elif (USED_UART_DEBUG_PORT==1)
-	/*
-	 * Initialize UART1 pin connect
-	 */
-	PinCfg.Funcnum = 1;
-	PinCfg.OpenDrain = 0;
-	PinCfg.Pinmode = 0;
-	PinCfg.Pinnum = 15;
-	PinCfg.Portnum = 0;
-	PINSEL_ConfigPin(&PinCfg);
-	PinCfg.Pinnum = 16;
-	PINSEL_ConfigPin(&PinCfg);
-#endif
-
-	/* Initialize UART Configuration parameter structure to default state:
-	 * Baudrate = 9600bps
-	 * 8 data bit
-	 * 1 Stop bit
-	 * None parity
-	 */
-	UART_ConfigStructInit(&UARTConfigStruct);
-
-	// Re-configure baudrate to 115200bps
-	UARTConfigStruct.Baud_rate = 115200;
-
-	// Initialize DEBUG_UART_PORT peripheral with given to corresponding parameter
-	UART_Init((LPC_UART_TypeDef *)DEBUG_UART_PORT, &UARTConfigStruct);
-
-	// Enable UART Transmit
-	UART_TxCmd((LPC_UART_TypeDef *)DEBUG_UART_PORT, ENABLE);
+void debug_frmwrk_init(void) {
+  UART_CFG_Type UARTConfigStruct;
+  PINSEL_CFG_Type PinCfg;
+
+  #if (USED_UART_DEBUG_PORT==0)
+    /*
+     * Initialize UART0 pin connect
+     */
+    PinCfg.Funcnum = 1;
+    PinCfg.OpenDrain = 0;
+    PinCfg.Pinmode = 0;
+    PinCfg.Pinnum = 2;
+    PinCfg.Portnum = 0;
+    PINSEL_ConfigPin(&PinCfg);
+    PinCfg.Pinnum = 3;
+    PINSEL_ConfigPin(&PinCfg);
+
+  #elif (USED_UART_DEBUG_PORT==1)
+    /*
+     * Initialize UART1 pin connect
+     */
+    PinCfg.Funcnum = 1;
+    PinCfg.OpenDrain = 0;
+    PinCfg.Pinmode = 0;
+    PinCfg.Pinnum = 15;
+    PinCfg.Portnum = 0;
+    PINSEL_ConfigPin(&PinCfg);
+    PinCfg.Pinnum = 16;
+    PINSEL_ConfigPin(&PinCfg);
+  #endif
+
+  /* Initialize UART Configuration parameter structure to default state:
+   * Baudrate = 9600bps
+   * 8 data bit
+   * 1 Stop bit
+   * None parity
+   */
+  UART_ConfigStructInit(&UARTConfigStruct);
+
+  // Re-configure baudrate to 115200bps
+  UARTConfigStruct.Baud_rate = 115200;
+
+  // Initialize DEBUG_UART_PORT peripheral with given to corresponding parameter
+  UART_Init((LPC_UART_TypeDef *)DEBUG_UART_PORT, &UARTConfigStruct);
+
+  // Enable UART Transmit
+  UART_TxCmd((LPC_UART_TypeDef *)DEBUG_UART_PORT, ENABLE);
 
   debug_frmwrk_initialized = TRUE;
 }
-#endif /*_DBGFWK */
-
 
-/* --------------------------------- End Of File ------------------------------ */
+#endif // _DBGFWK