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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: uartsw2.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>uartsw2.c</h1><a href="uartsw2_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/*! \file uartsw2.c \brief Software Interrupt-driven UART Driver. */</span>00002 <span class="comment">//*****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'uartsw2.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 : 0.6</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="uartsw2_8h.html">uartsw2.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> u08 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_8c.html#a9">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 <span class="preprocessor"> #ifdef UARTSW_INVERT</span>00056 <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>);00057 <span class="preprocessor"> #else</span>00058 <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>);00059 <span class="preprocessor"> #endif</span>00060 <span class="preprocessor"></span> 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>);00061 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>);00062 <span class="comment">// initialize baud rate</span>00063 <a class="code" href="uartsw_8c.html#a12">uartswSetBaudRate</a>(9600);00064 00065 <span class="comment">// setup the transmitter</span>00066 UartswTxBusy = FALSE;00067 <span class="comment">// disable OC2 interrupt</span>00068 cbi(TIMSK, OCIE2);00069 <span class="comment">// attach TxBit service routine to OC2</span>00070 <a class="code" href="group__timer.html#ga8">timerAttach</a>(TIMER2OUTCOMPARE_INT, <a class="code" href="uartsw_8c.html#a16">uartswTxBitService</a>);00071 00072 <span class="comment">// setup the receiver</span>00073 UartswRxBusy = FALSE;00074 <span class="comment">// disable OC0 interrupt</span>00075 cbi(TIMSK, OCIE0);00076 <span class="comment">// attach RxBit service routine to OC0</span>00077 <a class="code" href="group__timer.html#ga8">timerAttach</a>(TIMER0OUTCOMPARE_INT, <a class="code" href="uartsw_8c.html#a17">uartswRxBitService</a>);00078 <span class="comment">// INT2 trigger on rising/falling edge</span>00079 <span class="preprocessor"> #ifdef UARTSW_INVERT</span>00080 <span class="preprocessor"></span> sbi(MCUCSR, ISC2); <span class="comment">// rising edge</span>00081 <span class="preprocessor"> #else</span>00082 <span class="preprocessor"></span> cbi(MCUCSR, ISC2); <span class="comment">// falling edge</span>00083 <span class="preprocessor"> #endif</span>00084 <span class="preprocessor"></span> <span class="comment">// enable INT2 interrupt</span>00085 sbi(GICR, INT2);00086 00087 <span class="comment">// turn on interrupts</span>00088 sei();00089 }00090 <span class="comment"></span>00091 <span class="comment">//! create and initialize the uart buffers</span><a name="l00092"></a><a class="code" href="uartsw2_8c.html#a10">00092</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>)00093 {00094 <span class="comment">// initialize the UART receive buffer</span>00095 <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>);00096 }00097 <span class="comment"></span>00098 <span class="comment">//! turns off software UART</span><a name="l00099"></a><a class="code" href="uartsw2_8c.html#a11">00099</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>)00100 {00101 <span class="comment">// disable interrupts</span>00102 cbi(TIMSK, OCIE2);00103 cbi(TIMSK, OCIE0);00104 cbi(GICR, INT2);00105 <span class="comment">// detach the service routines</span>00106 <a class="code" href="group__timer.html#ga9">timerDetach</a>(TIMER2OUTCOMPARE_INT);00107 <a class="code" href="group__timer.html#ga9">timerDetach</a>(TIMER0OUTCOMPARE_INT);00108 }00109 <a name="l00110"></a><a class="code" href="uartsw2_8c.html#a12">00110</a> <span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a12">uartswSetBaudRate</a>(u32 baudrate)00111 {00112 u16 div;00113 00114 <span class="comment">// set timer prescaler</span>00115 <span class="keywordflow">if</span>( baudrate > (F_CPU/64L*256L) )00116 {00117 <span class="comment">// if the requested baud rate is high,</span>00118 <span class="comment">// set timer prescalers to div-by-64</span>00119 <a class="code" href="group__timer128.html#ga8">timer2SetPrescaler</a>(<a class="code" href="group__timer.html#ga28">TIMERRTC_CLK_DIV64</a>);00120 <a class="code" href="group__timer.html#ga4">timer0SetPrescaler</a>(<a class="code" href="group__timer.html#ga18">TIMER_CLK_DIV64</a>);00121 div = 64;00122 }00123 <span class="keywordflow">else</span>00124 {00125 <span class="comment">// if the requested baud rate is low,</span>00126 <span class="comment">// set timer prescalers to div-by-256</span>00127 <a class="code" href="group__timer128.html#ga8">timer2SetPrescaler</a>(<a class="code" href="group__timer.html#ga30">TIMERRTC_CLK_DIV256</a>);00128 <a class="code" href="group__timer.html#ga4">timer0SetPrescaler</a>(<a class="code" href="group__timer.html#ga19">TIMER_CLK_DIV256</a>);00129 div = 256;00130 }00131 00132 <span class="comment">// calculate division factor for requested baud rate, and set it</span>00133 <span class="comment">//UartswBaudRateDiv = (u08)(((F_CPU/64L)+(baudrate/2L))/(baudrate*1L));</span>00134 <span class="comment">//UartswBaudRateDiv = (u08)(((F_CPU/256L)+(baudrate/2L))/(baudrate*1L));</span>00135 UartswBaudRateDiv = (u08)(((F_CPU/div)+(baudrate/2L))/(baudrate*1L));00136 }00137 <span class="comment"></span>00138 <span class="comment">//! returns the receive buffer structure </span><a name="l00139"></a><a class="code" href="uartsw2_8c.html#a13">00139</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>)00140 {00141 <span class="comment">// return rx buffer pointer</span>00142 <span class="keywordflow">return</span> &uartswRxBuffer;00143 }00144 <a name="l00145"></a><a class="code" href="uartsw2_8c.html#a14">00145</a> <span class="keywordtype">void</span> <a class="code" href="uartsw_8c.html#a14">uartswSendByte</a>(u08 data)00146 {00147 <span class="comment">// wait until uart is ready</span>00148 <span class="keywordflow">while</span>(UartswTxBusy);00149 <span class="comment">// set busy flag</span>00150 UartswTxBusy = TRUE;00151 <span class="comment">// save data</span>00152 UartswTxData = data;00153 <span class="comment">// set number of bits (+1 for stop bit)</span>00154 UartswTxBitNum = 9;⌨️ 快捷键说明
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