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- /*
- HardwareSerial.cpp - Hardware serial library for Wiring
- Copyright (c) 2006 Nicholas Zambetti. All right reserved.
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- This library 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, write to the Free Software
- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-
- Modified 23 November 2006 by David A. Mellis
- Modified 28 September 2010 by Mark Sproul
- Modified 14 August 2012 by Alarus
- */
-
- #include <stdlib.h>
- #include <stdio.h>
- #include <string.h>
- #include <inttypes.h>
- #include "Arduino.h"
- #include "wiring_private.h"
-
- // this next line disables the entire HardwareSerial.cpp,
- // this is so I can support Attiny series and any other chip without a uart
- #if defined(UBRRH) || defined(UBRR0H) || defined(UBRR1H) || defined(UBRR2H) || defined(UBRR3H)
-
- #include "HardwareSerial.h"
-
- /*
- * on ATmega8, the uart and its bits are not numbered, so there is no "TXC0"
- * definition.
- */
- #if !defined(TXC0)
- #if defined(TXC)
- #define TXC0 TXC
- #elif defined(TXC1)
- // Some devices have uart1 but no uart0
- #define TXC0 TXC1
- #else
- #error TXC0 not definable in HardwareSerial.h
- #endif
- #endif
-
- // Define constants and variables for buffering incoming serial data. We're
- // using a ring buffer (I think), in which head is the index of the location
- // to which to write the next incoming character and tail is the index of the
- // location from which to read.
- #if (RAMEND < 1000)
- #define SERIAL_BUFFER_SIZE 16
- #else
- #define SERIAL_BUFFER_SIZE 64
- #endif
-
- struct ring_buffer
- {
- unsigned char buffer[SERIAL_BUFFER_SIZE];
- volatile unsigned int head;
- volatile unsigned int tail;
- };
-
- #if defined(USBCON)
- ring_buffer rx_buffer = { { 0 }, 0, 0};
- ring_buffer tx_buffer = { { 0 }, 0, 0};
- #endif
- #if defined(UBRRH) || defined(UBRR0H)
- ring_buffer rx_buffer = { { 0 }, 0, 0 };
- ring_buffer tx_buffer = { { 0 }, 0, 0 };
- #endif
- #if defined(UBRR1H)
- ring_buffer rx_buffer1 = { { 0 }, 0, 0 };
- ring_buffer tx_buffer1 = { { 0 }, 0, 0 };
- #endif
- #if defined(UBRR2H)
- ring_buffer rx_buffer2 = { { 0 }, 0, 0 };
- ring_buffer tx_buffer2 = { { 0 }, 0, 0 };
- #endif
- #if defined(UBRR3H)
- ring_buffer rx_buffer3 = { { 0 }, 0, 0 };
- ring_buffer tx_buffer3 = { { 0 }, 0, 0 };
- #endif
-
- inline void store_char(unsigned char c, ring_buffer *buffer)
- {
- int i = (unsigned int)(buffer->head + 1) % SERIAL_BUFFER_SIZE;
-
- // if we should be storing the received character into the location
- // just before the tail (meaning that the head would advance to the
- // current location of the tail), we're about to overflow the buffer
- // and so we don't write the character or advance the head.
- if (i != buffer->tail) {
- buffer->buffer[buffer->head] = c;
- buffer->head = i;
- }
- }
-
- #if !defined(USART0_RX_vect) && defined(USART1_RX_vect)
- // do nothing - on the 32u4 the first USART is USART1
- #else
- #if !defined(USART_RX_vect) && !defined(SIG_USART0_RECV) && \
- !defined(SIG_UART0_RECV) && !defined(USART0_RX_vect) && \
- !defined(SIG_UART_RECV)
- #error "Don't know what the Data Received vector is called for the first UART"
- #else
- void serialEvent() __attribute__((weak));
- void serialEvent() {}
- #define serialEvent_implemented
- #if defined(USART_RX_vect)
- SIGNAL(USART_RX_vect)
- #elif defined(SIG_USART0_RECV)
- SIGNAL(SIG_USART0_RECV)
- #elif defined(SIG_UART0_RECV)
- SIGNAL(SIG_UART0_RECV)
- #elif defined(USART0_RX_vect)
- SIGNAL(USART0_RX_vect)
- #elif defined(SIG_UART_RECV)
- SIGNAL(SIG_UART_RECV)
- #endif
- {
- #if defined(UDR0)
- if (bit_is_clear(UCSR0A, UPE0)) {
- unsigned char c = UDR0;
- store_char(c, &rx_buffer);
- } else {
- unsigned char c = UDR0;
- };
- #elif defined(UDR)
- if (bit_is_clear(UCSRA, PE)) {
- unsigned char c = UDR;
- store_char(c, &rx_buffer);
- } else {
- unsigned char c = UDR;
- };
- #else
- #error UDR not defined
- #endif
- }
- #endif
- #endif
-
- #if defined(USART1_RX_vect)
- void serialEvent1() __attribute__((weak));
- void serialEvent1() {}
- #define serialEvent1_implemented
- SIGNAL(USART1_RX_vect)
- {
- if (bit_is_clear(UCSR1A, UPE1)) {
- unsigned char c = UDR1;
- store_char(c, &rx_buffer1);
- } else {
- unsigned char c = UDR1;
- };
- }
- #elif defined(SIG_USART1_RECV)
- #error SIG_USART1_RECV
- #endif
-
- #if defined(USART2_RX_vect) && defined(UDR2)
- void serialEvent2() __attribute__((weak));
- void serialEvent2() {}
- #define serialEvent2_implemented
- SIGNAL(USART2_RX_vect)
- {
- if (bit_is_clear(UCSR2A, UPE2)) {
- unsigned char c = UDR2;
- store_char(c, &rx_buffer2);
- } else {
- unsigned char c = UDR2;
- };
- }
- #elif defined(SIG_USART2_RECV)
- #error SIG_USART2_RECV
- #endif
-
- #if defined(USART3_RX_vect) && defined(UDR3)
- void serialEvent3() __attribute__((weak));
- void serialEvent3() {}
- #define serialEvent3_implemented
- SIGNAL(USART3_RX_vect)
- {
- if (bit_is_clear(UCSR3A, UPE3)) {
- unsigned char c = UDR3;
- store_char(c, &rx_buffer3);
- } else {
- unsigned char c = UDR3;
- };
- }
- #elif defined(SIG_USART3_RECV)
- #error SIG_USART3_RECV
- #endif
-
- void serialEventRun(void)
- {
- #ifdef serialEvent_implemented
- if (Serial.available()) serialEvent();
- #endif
- #ifdef serialEvent1_implemented
- if (Serial1.available()) serialEvent1();
- #endif
- #ifdef serialEvent2_implemented
- if (Serial2.available()) serialEvent2();
- #endif
- #ifdef serialEvent3_implemented
- if (Serial3.available()) serialEvent3();
- #endif
- }
-
-
- #if !defined(USART0_UDRE_vect) && defined(USART1_UDRE_vect)
- // do nothing - on the 32u4 the first USART is USART1
- #else
- #if !defined(UART0_UDRE_vect) && !defined(UART_UDRE_vect) && !defined(USART0_UDRE_vect) && !defined(USART_UDRE_vect)
- #error "Don't know what the Data Register Empty vector is called for the first UART"
- #else
- #if defined(UART0_UDRE_vect)
- ISR(UART0_UDRE_vect)
- #elif defined(UART_UDRE_vect)
- ISR(UART_UDRE_vect)
- #elif defined(USART0_UDRE_vect)
- ISR(USART0_UDRE_vect)
- #elif defined(USART_UDRE_vect)
- ISR(USART_UDRE_vect)
- #endif
- {
- if (tx_buffer.head == tx_buffer.tail) {
- // Buffer empty, so disable interrupts
- #if defined(UCSR0B)
- cbi(UCSR0B, UDRIE0);
- #else
- cbi(UCSRB, UDRIE);
- #endif
- }
- else {
- // There is more data in the output buffer. Send the next byte
- unsigned char c = tx_buffer.buffer[tx_buffer.tail];
- tx_buffer.tail = (tx_buffer.tail + 1) % SERIAL_BUFFER_SIZE;
-
- #if defined(UDR0)
- UDR0 = c;
- #elif defined(UDR)
- UDR = c;
- #else
- #error UDR not defined
- #endif
- }
- }
- #endif
- #endif
-
- #ifdef USART1_UDRE_vect
- ISR(USART1_UDRE_vect)
- {
- if (tx_buffer1.head == tx_buffer1.tail) {
- // Buffer empty, so disable interrupts
- cbi(UCSR1B, UDRIE1);
- }
- else {
- // There is more data in the output buffer. Send the next byte
- unsigned char c = tx_buffer1.buffer[tx_buffer1.tail];
- tx_buffer1.tail = (tx_buffer1.tail + 1) % SERIAL_BUFFER_SIZE;
-
- UDR1 = c;
- }
- }
- #endif
-
- #ifdef USART2_UDRE_vect
- ISR(USART2_UDRE_vect)
- {
- if (tx_buffer2.head == tx_buffer2.tail) {
- // Buffer empty, so disable interrupts
- cbi(UCSR2B, UDRIE2);
- }
- else {
- // There is more data in the output buffer. Send the next byte
- unsigned char c = tx_buffer2.buffer[tx_buffer2.tail];
- tx_buffer2.tail = (tx_buffer2.tail + 1) % SERIAL_BUFFER_SIZE;
-
- UDR2 = c;
- }
- }
- #endif
-
- #ifdef USART3_UDRE_vect
- ISR(USART3_UDRE_vect)
- {
- if (tx_buffer3.head == tx_buffer3.tail) {
- // Buffer empty, so disable interrupts
- cbi(UCSR3B, UDRIE3);
- }
- else {
- // There is more data in the output buffer. Send the next byte
- unsigned char c = tx_buffer3.buffer[tx_buffer3.tail];
- tx_buffer3.tail = (tx_buffer3.tail + 1) % SERIAL_BUFFER_SIZE;
-
- UDR3 = c;
- }
- }
- #endif
-
-
- // Constructors ////////////////////////////////////////////////////////////////
-
- HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer,
- volatile uint8_t *ubrrh, volatile uint8_t *ubrrl,
- volatile uint8_t *ucsra, volatile uint8_t *ucsrb,
- volatile uint8_t *ucsrc, volatile uint8_t *udr,
- uint8_t rxen, uint8_t txen, uint8_t rxcie, uint8_t udrie, uint8_t u2x)
- {
- _rx_buffer = rx_buffer;
- _tx_buffer = tx_buffer;
- _ubrrh = ubrrh;
- _ubrrl = ubrrl;
- _ucsra = ucsra;
- _ucsrb = ucsrb;
- _ucsrc = ucsrc;
- _udr = udr;
- _rxen = rxen;
- _txen = txen;
- _rxcie = rxcie;
- _udrie = udrie;
- _u2x = u2x;
- }
-
- // Public Methods //////////////////////////////////////////////////////////////
-
- void HardwareSerial::begin(unsigned long baud)
- {
- uint16_t baud_setting;
- bool use_u2x = true;
-
- #if F_CPU == 16000000UL
- // hardcoded exception for compatibility with the bootloader shipped
- // with the Duemilanove and previous boards and the firmware on the 8U2
- // on the Uno and Mega 2560.
- if (baud == 57600) {
- use_u2x = false;
- }
- #endif
-
- try_again:
-
- if (use_u2x) {
- *_ucsra = 1 << _u2x;
- baud_setting = (F_CPU / 4 / baud - 1) / 2;
- } else {
- *_ucsra = 0;
- baud_setting = (F_CPU / 8 / baud - 1) / 2;
- }
-
- if ((baud_setting > 4095) && use_u2x)
- {
- use_u2x = false;
- goto try_again;
- }
-
- // assign the baud_setting, a.k.a. ubbr (USART Baud Rate Register)
- *_ubrrh = baud_setting >> 8;
- *_ubrrl = baud_setting;
-
- transmitting = false;
-
- sbi(*_ucsrb, _rxen);
- sbi(*_ucsrb, _txen);
- sbi(*_ucsrb, _rxcie);
- cbi(*_ucsrb, _udrie);
- }
-
- void HardwareSerial::begin(unsigned long baud, byte config)
- {
- uint16_t baud_setting;
- uint8_t current_config;
- bool use_u2x = true;
-
- #if F_CPU == 16000000UL
- // hardcoded exception for compatibility with the bootloader shipped
- // with the Duemilanove and previous boards and the firmware on the 8U2
- // on the Uno and Mega 2560.
- if (baud == 57600) {
- use_u2x = false;
- }
- #endif
-
- try_again:
-
- if (use_u2x) {
- *_ucsra = 1 << _u2x;
- baud_setting = (F_CPU / 4 / baud - 1) / 2;
- } else {
- *_ucsra = 0;
- baud_setting = (F_CPU / 8 / baud - 1) / 2;
- }
-
- if ((baud_setting > 4095) && use_u2x)
- {
- use_u2x = false;
- goto try_again;
- }
-
- // assign the baud_setting, a.k.a. ubbr (USART Baud Rate Register)
- *_ubrrh = baud_setting >> 8;
- *_ubrrl = baud_setting;
-
- //set the data bits, parity, and stop bits
- #if defined(__AVR_ATmega8__)
- config |= 0x80; // select UCSRC register (shared with UBRRH)
- #endif
- *_ucsrc = config;
-
- sbi(*_ucsrb, _rxen);
- sbi(*_ucsrb, _txen);
- sbi(*_ucsrb, _rxcie);
- cbi(*_ucsrb, _udrie);
- }
-
- void HardwareSerial::end()
- {
- // wait for transmission of outgoing data
- while (_tx_buffer->head != _tx_buffer->tail)
- ;
-
- cbi(*_ucsrb, _rxen);
- cbi(*_ucsrb, _txen);
- cbi(*_ucsrb, _rxcie);
- cbi(*_ucsrb, _udrie);
-
- // clear any received data
- _rx_buffer->head = _rx_buffer->tail;
- }
-
- int HardwareSerial::available(void)
- {
- return (unsigned int)(SERIAL_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % SERIAL_BUFFER_SIZE;
- }
-
- int HardwareSerial::peek(void)
- {
- if (_rx_buffer->head == _rx_buffer->tail) {
- return -1;
- } else {
- return _rx_buffer->buffer[_rx_buffer->tail];
- }
- }
-
- int HardwareSerial::read(void)
- {
- // if the head isn't ahead of the tail, we don't have any characters
- if (_rx_buffer->head == _rx_buffer->tail) {
- return -1;
- } else {
- unsigned char c = _rx_buffer->buffer[_rx_buffer->tail];
- _rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE;
- return c;
- }
- }
-
- void HardwareSerial::flush()
- {
- // UDR is kept full while the buffer is not empty, so TXC triggers when EMPTY && SENT
- while (transmitting && ! (*_ucsra & _BV(TXC0)));
- transmitting = false;
- }
-
- size_t HardwareSerial::write(uint8_t c)
- {
- int i = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE;
-
- // If the output buffer is full, there's nothing for it other than to
- // wait for the interrupt handler to empty it a bit
- // ???: return 0 here instead?
- while (i == _tx_buffer->tail)
- ;
-
- _tx_buffer->buffer[_tx_buffer->head] = c;
- _tx_buffer->head = i;
-
- sbi(*_ucsrb, _udrie);
- // clear the TXC bit -- "can be cleared by writing a one to its bit location"
- transmitting = true;
- sbi(*_ucsra, TXC0);
-
- return 1;
- }
-
- HardwareSerial::operator bool() {
- return true;
- }
-
- // Preinstantiate Objects //////////////////////////////////////////////////////
-
- #if defined(UBRRH) && defined(UBRRL)
- HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR, RXEN, TXEN, RXCIE, UDRIE, U2X);
- #elif defined(UBRR0H) && defined(UBRR0L)
- HardwareSerial Serial(&rx_buffer, &tx_buffer, &UBRR0H, &UBRR0L, &UCSR0A, &UCSR0B, &UCSR0C, &UDR0, RXEN0, TXEN0, RXCIE0, UDRIE0, U2X0);
- #elif defined(USBCON)
- // do nothing - Serial object and buffers are initialized in CDC code
- #else
- #error no serial port defined (port 0)
- #endif
-
- #if defined(UBRR1H)
- HardwareSerial Serial1(&rx_buffer1, &tx_buffer1, &UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UCSR1C, &UDR1, RXEN1, TXEN1, RXCIE1, UDRIE1, U2X1);
- #endif
- #if defined(UBRR2H)
- HardwareSerial Serial2(&rx_buffer2, &tx_buffer2, &UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UCSR2C, &UDR2, RXEN2, TXEN2, RXCIE2, UDRIE2, U2X2);
- #endif
- #if defined(UBRR3H)
- HardwareSerial Serial3(&rx_buffer3, &tx_buffer3, &UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3, RXEN3, TXEN3, RXCIE3, UDRIE3, U2X3);
- #endif
-
- #endif // whole file
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