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Diffstat (limited to 'common/uart.c')
| -rw-r--r-- | common/uart.c | 129 |
1 files changed, 0 insertions, 129 deletions
diff --git a/common/uart.c b/common/uart.c deleted file mode 100644 index c17649b08..000000000 --- a/common/uart.c +++ /dev/null @@ -1,129 +0,0 @@ -// TODO: Teensy support(ATMega32u4/AT90USB128) -// Fixed for Arduino Duemilanove ATmega168p by Jun Wako -/* UART Example for Teensy USB Development Board - * http://www.pjrc.com/teensy/ - * Copyright (c) 2009 PJRC.COM, LLC - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ - -// Version 1.0: Initial Release -// Version 1.1: Add support for Teensy 2.0, minor optimizations - - -#include <avr/io.h> -#include <avr/interrupt.h> - -#include "uart.h" - -// These buffers may be any size from 2 to 256 bytes. -#define RX_BUFFER_SIZE 64 -#define TX_BUFFER_SIZE 40 - -static volatile uint8_t tx_buffer[TX_BUFFER_SIZE]; -static volatile uint8_t tx_buffer_head; -static volatile uint8_t tx_buffer_tail; -static volatile uint8_t rx_buffer[RX_BUFFER_SIZE]; -static volatile uint8_t rx_buffer_head; -static volatile uint8_t rx_buffer_tail; - -// Initialize the UART -void uart_init(uint32_t baud) -{ - cli(); - UBRR0 = (F_CPU / 4 / baud - 1) / 2; - UCSR0A = (1<<U2X0); - UCSR0B = (1<<RXEN0) | (1<<TXEN0) | (1<<RXCIE0); - UCSR0C = (1<<UCSZ01) | (1<<UCSZ00); - tx_buffer_head = tx_buffer_tail = 0; - rx_buffer_head = rx_buffer_tail = 0; - sei(); -} - -// Transmit a byte -void uart_putchar(uint8_t c) -{ - uint8_t i; - - i = tx_buffer_head + 1; - if (i >= TX_BUFFER_SIZE) i = 0; - while (tx_buffer_tail == i) ; // wait until space in buffer - //cli(); - tx_buffer[i] = c; - tx_buffer_head = i; - UCSR0B = (1<<RXEN0) | (1<<TXEN0) | (1<<RXCIE0) | (1<<UDRIE0); - //sei(); -} - -// Receive a byte -uint8_t uart_getchar(void) -{ - uint8_t c, i; - - while (rx_buffer_head == rx_buffer_tail) ; // wait for character - i = rx_buffer_tail + 1; - if (i >= RX_BUFFER_SIZE) i = 0; - c = rx_buffer[i]; - rx_buffer_tail = i; - return c; -} - -// Return the number of bytes waiting in the receive buffer. -// Call this before uart_getchar() to check if it will need -// to wait for a byte to arrive. -uint8_t uart_available(void) -{ - uint8_t head, tail; - - head = rx_buffer_head; - tail = rx_buffer_tail; - if (head >= tail) return head - tail; - return RX_BUFFER_SIZE + head - tail; -} - -// Transmit Interrupt -ISR(USART_UDRE_vect) -{ - uint8_t i; - - if (tx_buffer_head == tx_buffer_tail) { - // buffer is empty, disable transmit interrupt - UCSR0B = (1<<RXEN0) | (1<<TXEN0) | (1<<RXCIE0); - } else { - i = tx_buffer_tail + 1; - if (i >= TX_BUFFER_SIZE) i = 0; - UDR0 = tx_buffer[i]; - tx_buffer_tail = i; - } -} - -// Receive Interrupt -ISR(USART_RX_vect) -{ - uint8_t c, i; - - c = UDR0; - i = rx_buffer_head + 1; - if (i >= RX_BUFFER_SIZE) i = 0; - if (i != rx_buffer_tail) { - rx_buffer[i] = c; - rx_buffer_head = i; - } -} - |