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/************************************************************************
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Title:    Interrupt UART library with receive/transmit circular buffers
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Author:   Peter Fleury <pfleury@gmx.ch>   http://jump.to/fleury
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File:     $Id: uart.h,v 1.8.2.1 2007/07/01 11:14:38 peter Exp $
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Software: AVR-GCC 4.1, AVR Libc 1.4
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Hardware: any AVR with built-in UART, tested on AT90S8515 & ATmega8 at 4 Mhz
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License:  GNU General Public License
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Usage:    see Doxygen manual
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LICENSE:
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    Copyright (C) 2006 Peter Fleury
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    This program is free software; you can redistribute it and/or modify
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    it under the terms of the GNU General Public License as published by
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    the Free Software Foundation; either version 2 of the License, or
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    any later version.
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    This program is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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    GNU General Public License for more details.
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************************************************************************/
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//
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//  @defgroup pfleury_uart UART Library
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//  @code #include <uart.h> @endcode
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//
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//  @brief Interrupt UART library using the built-in UART with transmit and receive circular buffers.
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//
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//  This library can be used to transmit and receive data through the built in UART.
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//
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//  An interrupt is generated when the UART has finished transmitting or
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//  receiving a byte. The interrupt handling routines use circular buffers
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//  for buffering received and transmitted data.
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//
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//  The UART_RX_BUFFER_SIZE and UART_TX_BUFFER_SIZE constants define
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//  the size of the circular buffers in bytes. Note that these constants must be a power of 2.
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//  You may need to adapt this constants to your target and your application by adding
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//  CDEFS += -DUART_RX_BUFFER_SIZE=nn -DUART_RX_BUFFER_SIZE=nn to your Makefile.
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//
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//  @note Based on Atmel Application Note AVR306
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//  @author Peter Fleury pfleury@gmx.ch  http://jump.to/fleury
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//
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#ifndef UART_H
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#define UART_H
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#if (__GNUC__ * 100 + __GNUC_MINOR__) < 304
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#error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !"
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#endif
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// constants and macros
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// @brief  UART Baudrate Expression
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//  @param  xtalcpu  system clock in Mhz, e.g. 4000000L for 4Mhz
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//  @param  baudrate baudrate in bps, e.g. 1200, 2400, 9600
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//
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#define UART_BAUD_SELECT(baudRate,xtalCpu) ((xtalCpu)/((baudRate)*16l)-1)
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// @brief  UART Baudrate Expression for ATmega double speed mode
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//  @param  xtalcpu  system clock in Mhz, e.g. 4000000L for 4Mhz
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//  @param  baudrate baudrate in bps, e.g. 1200, 2400, 9600
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//
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#define UART_BAUD_SELECT_DOUBLE_SPEED(baudRate,xtalCpu) (((xtalCpu)/((baudRate)*8l)-1)|0x8000)
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// Size of the circular receive buffer, must be power of 2
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#ifndef UART_RX_BUFFER_SIZE
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#define UART_RX_BUFFER_SIZE 32
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#endif
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// Size of the circular transmit buffer, must be power of 2
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#ifndef UART_TX_BUFFER_SIZE
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#define UART_TX_BUFFER_SIZE 32
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#endif
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// test if the size of the circular buffers fits into SRAM
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#if ( (UART_RX_BUFFER_SIZE+UART_TX_BUFFER_SIZE) >= (RAMEND-0x60 ) )
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#error "size of UART_RX_BUFFER_SIZE + UART_TX_BUFFER_SIZE larger than size of SRAM"
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#endif
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// high byte error return code of uart_getc()
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#define UART_FRAME_ERROR      0x0800              // Framing Error by UART
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#define UART_OVERRUN_ERROR    0x0400              // Overrun condition by UART
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#define UART_BUFFER_OVERFLOW  0x0200              // receive ringbuffer overflow
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#define UART_NO_DATA          0x0100              // no receive data available
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//
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// function prototypes
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//
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//
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//   @brief   Initialize UART and set baudrate
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//   @param   baudrate Specify baudrate using macro UART_BAUD_SELECT()
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//   @return  none
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//
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extern void uart_init(unsigned int baudrate);
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//
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//  @brief   Get received byte from ringbuffer
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//
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// Returns in the lower byte the received character and in the
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// higher byte the last receive error.
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// UART_NO_DATA is returned when no data is available.
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//
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//  @param   void
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//  @return  lower byte:  received byte from ringbuffer
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//  @return  higher byte: last receive status
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//           - \b 0 successfully received data from UART
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//           - \b UART_NO_DATA
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//             <br>no receive data available
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//           - \b UART_BUFFER_OVERFLOW
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//             <br>Receive ringbuffer overflow.
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//             We are not reading the receive buffer fast enough,
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//             one or more received character have been dropped
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//           - \b UART_OVERRUN_ERROR
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//             <br>Overrun condition by UART.
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//             A character already present in the UART UDR register was
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//             not read by the interrupt handler before the next character arrived,
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//             one or more received characters have been dropped.
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//           - \b UART_FRAME_ERROR
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//             <br>Framing Error by UART
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//
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extern unsigned int uart_getc(void);
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//
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//  @brief   Put byte to ringbuffer for transmitting via UART
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//  @param   data byte to be transmitted
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//  @return  none
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//
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// @brief  Initialize USART1 (only available on selected ATmegas) @see uart_init
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extern void uart1_init(unsigned int baudrate);
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// @brief  Get received byte of USART1 from ringbuffer. (only available on selected ATmega) @see uart_getc
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extern unsigned int uart1_getc(void);
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// @brief  Put byte to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_putc
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//extern void uart1_putc(unsigned char data);
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extern int uart1_putc(unsigned char data);
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// @brief  Put string to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_puts
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extern void uart1_puts(const char *s );
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// @brief  Put string from program memory to ringbuffer for transmitting via USART1 (only available on selected ATmega) @see uart_puts_p
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extern void uart1_puts_p(const char *s );
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// @brief  Macro to automatically put a string constant into program memory
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#define uart1_puts_P(__s)       uart1_puts_p(PSTR(__s))
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extern char *utoa1(char* buffer, const unsigned int size, unsigned int value);
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#endif // UART_H
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