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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"><title>Procyon AVRlib: uartsw.c Source File</title><link href="dox.css" rel="stylesheet" type="text/css"></head><body><!-- Generated by Doxygen 1.4.2 --><div class="qindex"><a class="qindex" href="main.html">Main Page</a> | <a class="qindex" href="modules.html">Modules</a> | <a class="qindex" href="annotated.html">Data Structures</a> | <a class="qindex" href="dirs.html">Directories</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="functions.html">Data Fields</a> | <a class="qindex" href="globals.html">Globals</a> | <a class="qindex" href="pages.html">Related Pages</a></div><h1>uartsw.c</h1><a href="uartsw_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/*! \file uartsw.c \brief Software Interrupt-driven UART Driver. */</span>00002 <span class="comment">//*****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'uartsw.c'</span>00005 <span class="comment">// Title : Software Interrupt-driven UART Driver</span>00006 <span class="comment">// Author : Pascal Stang - Copyright (C) 2002-2004</span>00007 <span class="comment">// Created : 7/20/2002</span>00008 <span class="comment">// Revised : 4/27/2004</span>00009 <span class="comment">// Version : 0.1</span>00010 <span class="comment">// Target MCU : Atmel AVR Series (intended for the ATmega16 and ATmega32)</span>00011 <span class="comment">// Editor Tabs : 4</span>00012 <span class="comment">//</span>00013 <span class="comment">// This code is distributed under the GNU Public License</span>00014 <span class="comment">// which can be found at http://www.gnu.org/licenses/gpl.txt</span>00015 <span class="comment">//</span>00016 <span class="comment">//*****************************************************************************</span>00017 00018 <span class="preprocessor">#include <avr/io.h></span>00019 <span class="preprocessor">#include <avr/interrupt.h></span>00020 00021 <span class="preprocessor">#include "<a class="code" href="global_8h.html">global.h</a>"</span>00022 <span class="preprocessor">#include "<a class="code" href="timer_8h.html">timer.h</a>"</span>00023 <span class="preprocessor">#include "<a class="code" href="uartsw_8h.html">uartsw.h</a>"</span>00024 00025 <span class="comment">// Program ROM constants</span>00026 00027 <span class="comment">// Global variables</span>00028 00029 <span class="comment">// uartsw transmit status and data variables</span>00030 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswTxBusy;00031 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswTxData;00032 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswTxBitNum;00033 00034 <span class="comment">// baud rate common to transmit and receive</span>00035 <span class="keyword">static</span> <span class="keyword">volatile</span> u16 UartswBaudRateDiv;00036 00037 <span class="comment">// uartsw receive status and data variables</span>00038 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswRxBusy;00039 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswRxData;00040 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswRxBitNum;00041 <span class="comment">// receive buffer</span>00042 <span class="keyword">static</span> <a class="code" href="structstruct__cBuffer.html">cBuffer</a> uartswRxBuffer; <span class="comment">///< uartsw receive buffer</span>00043 <span class="comment"></span><span class="comment">// automatically allocate space in ram for each buffer</span>00044 <span class="keyword">static</span> <span class="keywordtype">char</span> uartswRxData[<a class="code" href="uartsw2conf_8h.html#a0">UARTSW_RX_BUFFER_SIZE</a>];00045 00046 <span class="comment">// functions</span>00047 <span class="comment"></span>00048 <span class="comment">//! enable and initialize the software uart</span><a name="l00049"></a><a class="code" href="uartsw2_8h.html#a0">00049</a> <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a9">uartswInit</a>(<span class="keywordtype">void</span>)00050 {00051 <span class="comment">// initialize the buffers</span>00052 <a class="code" href="uartsw_8c.html#a10">uartswInitBuffers</a>();00053 <span class="comment">// initialize the ports</span>00054 sbi(<a class="code" href="uartsw2conf_8h.html#a3">UARTSW_TX_DDR</a>, <a class="code" href="uartsw2conf_8h.html#a4">UARTSW_TX_PIN</a>);00055 cbi(<a class="code" href="uartsw2conf_8h.html#a6">UARTSW_RX_DDR</a>, <a class="code" href="uartsw2conf_8h.html#a8">UARTSW_RX_PIN</a>);00056 cbi(<a class="code" href="uartsw2conf_8h.html#a5">UARTSW_RX_PORT</a>, <a class="code" href="uartsw2conf_8h.html#a8">UARTSW_RX_PIN</a>);00057 <span class="comment">// initialize baud rate</span>00058 <a class="code" href="uartsw_8c.html#a12">uartswSetBaudRate</a>(9600);00059 00060 <span class="comment">// setup the transmitter</span>00061 UartswTxBusy = FALSE;00062 <span class="comment">// disable OC1A interrupt</span>00063 cbi(TIMSK, OCIE1A);00064 <span class="comment">// attach TxBit service routine to OC1A</span>00065 <a class="code" href="group__timer.html#ga8">timerAttach</a>(TIMER1OUTCOMPAREA_INT, <a class="code" href="uartsw_8c.html#a16">uartswTxBitService</a>);00066 00067 <span class="comment">// setup the receiver</span>00068 UartswRxBusy = FALSE;00069 <span class="comment">// disable OC1B interrupt</span>00070 cbi(TIMSK, OCIE1B);00071 <span class="comment">// attach RxBit service routine to OC1B</span>00072 <a class="code" href="group__timer.html#ga8">timerAttach</a>(TIMER1OUTCOMPAREB_INT, <a class="code" href="uartsw_8c.html#a17">uartswRxBitService</a>);00073 <span class="comment">// attach RxBit service routine to ICP</span>00074 <a class="code" href="group__timer.html#ga8">timerAttach</a>(TIMER1INPUTCAPTURE_INT, <a class="code" href="uartsw_8c.html#a17">uartswRxBitService</a>);00075 <span class="preprocessor"> #ifdef UARTSW_INVERT </span>00076 <span class="preprocessor"></span> <span class="comment">// trigger on rising edge </span>00077 sbi(TCCR1B, ICES1); 00078 <span class="preprocessor"> #else </span>00079 <span class="preprocessor"></span> <span class="comment">// trigger on falling edge </span>00080 cbi(TCCR1B, ICES1); 00081 <span class="preprocessor"> #endif </span>00082 <span class="preprocessor"></span> <span class="comment">// enable ICP interrupt</span>00083 sbi(TIMSK, TICIE1);00084 00085 <span class="comment">// turn on interrupts</span>00086 sei();00087 }00088 <span class="comment"></span>00089 <span class="comment">//! create and initialize the uart buffers</span><a name="l00090"></a><a class="code" href="uartsw2_8h.html#a1">00090</a> <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a10">uartswInitBuffers</a>(<span class="keywordtype">void</span>)00091 {00092 <span class="comment">// initialize the UART receive buffer</span>00093 <a class="code" href="group__buffer.html#ga1">bufferInit</a>(&uartswRxBuffer, uartswRxData, <a class="code" href="uartsw2conf_8h.html#a0">UARTSW_RX_BUFFER_SIZE</a>);00094 }00095 <span class="comment"></span>00096 <span class="comment">//! turns off software UART</span><a name="l00097"></a><a class="code" href="uartsw2_8h.html#a2">00097</a> <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a11">uartswOff</a>(<span class="keywordtype">void</span>)00098 {00099 <span class="comment">// disable interrupts</span>00100 cbi(TIMSK, OCIE1A);00101 cbi(TIMSK, OCIE1B);00102 cbi(TIMSK, TICIE1);00103 <span class="comment">// detach the service routines</span>00104 <a class="code" href="group__timer.html#ga9">timerDetach</a>(TIMER1OUTCOMPAREA_INT);00105 <a class="code" href="group__timer.html#ga9">timerDetach</a>(TIMER1OUTCOMPAREB_INT);00106 <a class="code" href="group__timer.html#ga9">timerDetach</a>(TIMER1INPUTCAPTURE_INT);00107 }00108 <a name="l00109"></a><a class="code" href="uartsw2_8h.html#a4">00109</a> <span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a12">uartswSetBaudRate</a>(u32 baudrate)00110 {00111 <span class="comment">// set timer prescaler</span>00112 <a class="code" href="group__timer.html#ga6">timer1SetPrescaler</a>(<a class="code" href="group__timer.html#ga16">TIMER_CLK_DIV1</a>);00113 <span class="comment">// calculate division factor for requested baud rate, and set it</span>00114 UartswBaudRateDiv = (u16)((F_CPU+(baudrate/2L))/(baudrate*1L));00115 }00116 <span class="comment"></span>00117 <span class="comment">//! returns the receive buffer structure </span><a name="l00118"></a><a class="code" href="uartsw2_8h.html#a3">00118</a> <span class="comment"></span><a class="code" href="structstruct__cBuffer.html">cBuffer</a>* <a class="code" href="uartsw_8c.html#a13">uartswGetRxBuffer</a>(<span class="keywordtype">void</span>)00119 {00120 <span class="comment">// return rx buffer pointer</span>00121 <span class="keywordflow">return</span> &uartswRxBuffer;00122 }00123 <a name="l00124"></a><a class="code" href="uartsw2_8h.html#a5">00124</a> <span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a14">uartswSendByte</a>(u08 data)00125 {00126 <span class="comment">// wait until uart is ready</span>00127 <span class="keywordflow">while</span>(UartswTxBusy);00128 <span class="comment">// set busy flag</span>00129 UartswTxBusy = TRUE;00130 <span class="comment">// save data</span>00131 UartswTxData = data;00132 <span class="comment">// set number of bits (+1 for stop bit)</span>00133 UartswTxBitNum = 9;00134 00135 <span class="comment">// set the start bit</span>00136 <span class="preprocessor"> #ifdef UARTSW_INVERT</span>00137 <span class="preprocessor"></span> sbi(<a class="code" href="uartsw2conf_8h.html#a2">UARTSW_TX_PORT</a>, <a class="code" href="uartsw2conf_8h.html#a4">UARTSW_TX_PIN</a>);00138 <span class="preprocessor"> #else</span>00139 <span class="preprocessor"></span> cbi(<a class="code" href="uartsw2conf_8h.html#a2">UARTSW_TX_PORT</a>, <a class="code" href="uartsw2conf_8h.html#a4">UARTSW_TX_PIN</a>);00140 <span class="preprocessor"> #endif</span>00141 <span class="preprocessor"></span>00142 <span class="comment">// schedule the next bit</span>00143 outw(OCR1A, inw(TCNT1) + UartswBaudRateDiv);00144 <span class="comment">// enable OC1A interrupt</span>00145 sbi(TIMSK, OCIE1A);00146 }00147 <span class="comment"></span>00148 <span class="comment">//! gets a byte (if available) from the uart receive buffer</span><a name="l00149"></a><a class="code" href="uartsw2_8h.html#a6">00149</a> <span class="comment"></span>u08 <a class="code" href="uartsw_8c.html#a15">uartswReceiveByte</a>(u08* rxData)00150 {00151 <span class="comment">// make sure we have a receive buffer</span>00152 <span class="keywordflow">if</span>(uartswRxBuffer.<a class="code" href="structstruct__cBuffer.html#o1">size</a>)00153 {00154 <span class="comment">// make sure we have data</span>00155 <span class="keywordflow">if</span>(uartswRxBuffer.<a class="code" href="structstruct__cBuffer.html#o2">datalength</a>)00156 {00157 <span class="comment">// get byte from beginning of buffer</span>00158 *rxData = <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(&uartswRxBuffer);00159 <span class="keywordflow">return</span> TRUE;00160 }00161 <span class="keywordflow">else</span>00162 {00163 <span class="comment">// no data</span>00164 <span class="keywordflow">return</span> FALSE;00165 }00166 }00167 <span class="keywordflow">else</span>00168 {00169 <span class="comment">// no buffer</span>00170 <span class="keywordflow">return</span> FALSE;00171 }00172 }00173 <a name="l00174"></a><a class="code" href="uartsw2_8h.html#a7">00174</a> <span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a16">uartswTxBitService</a>(<span class="keywordtype">void</span>)00175 {00176 <span class="keywordflow">if</span>(UartswTxBitNum)00177 {00178 <span class="comment">// there are bits still waiting to be transmitted</span>00179 <span class="keywordflow">if</span>(UartswTxBitNum > 1)00180 {00181 <span class="comment">// transmit data bits (inverted, LSB first)</span>00182 <span class="preprocessor"> #ifdef UARTSW_INVERT</span>00183 <span class="preprocessor"></span> <span class="keywordflow">if</span>( !(UartswTxData & 0x01) )00184 <span class="preprocessor"> #else</span>00185 <span class="preprocessor"></span> <span class="keywordflow">if</span>( (UartswTxData & 0x01) )00186 <span class="preprocessor"> #endif</span>00187 <span class="preprocessor"></span> sbi(<a class="code" href="uartsw2conf_8h.html#a2">UARTSW_TX_PORT</a>, <a class="code" href="uartsw2conf_8h.html#a4">UARTSW_TX_PIN</a>);⌨️ 快捷键说明
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