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/*
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soft_uart
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v0.2
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Copyright John Steggall 2009
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*/
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/*
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Copyright 2009 John Steggall (steggall.j@gmail.com)
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Permission to use, copy, modify, and distribute this software
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and its documentation for any purpose and without fee is hereby
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granted, provided that the above copyright notice appear in all
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copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of the author not be used in
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advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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The author disclaim all warranties with regard to this
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software, including all implied warranties of merchantability
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and fitness. In no event shall the author be liable for any
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special, indirect or consequential damages or any damages
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whatsoever resulting from loss of use, data or profits, whether
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in an action of contract, negligence or other tortious action,
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arising out of or in connection with the use or performance of
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this software.
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*/
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/*
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Specifically designed for the xplain board, other uses could be made by adjusting uart_soft_conf.h
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replacing the port, pin and timer assignments. Also relies on and external interupt to detect the low
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level of the start bit, in this case INT0.
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Always configured to 9600baud. Can be changed by setting the BITLENGTH define to F_CPU/(desired baud)
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code may need optimising when getting any faster to sample the bit in the correct place. No
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compensation has been made for the response time of the int routine.
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Note: Configured to use 16bit timers.
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*/
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/* Changes
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*
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* v0.2
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* - Added configuration file to ease pain of setup for different hardware configuration
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* - Changed bit access for ports that can be accessed directly
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* - Fixed atomic section in uart_init to encompass counter read
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*/
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#ifndef UART_SOFT_H
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#define UART_SOFT_H
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/* status */
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extern uint8_t status;
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/* initialises software uart and enables transmit */
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extern void SoftUART_Init(void);
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/* checks if there is a byte in the receive buffer*/
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extern unsigned char SoftUART_IsReceived(void);
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/* returns the received byte */
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extern unsigned char SoftUART_RxByte(void);
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/* starts a byte send and returns the byte to be sent */
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extern unsigned char SoftUART_TxByte(unsigned char data);
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/* Simulates polling UDRE to see if tx buffer is empty and ready */
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extern unsigned char SoftUART_IsReady(void);
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#endif
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