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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 1.3.6 --><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="files.html">File List</a> | <a class="qindex" href="functions.html">Data Fields</a> | <a class="qindex" href="globals.html">Globals</a></div><h1>uartsw2.c</h1><a href="uartsw2_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre>00001 <span class="comment">/*! \file uartsw2.c \brief Interrupt-driven Software 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 : Interrupt-driven Software 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 <span class="preprocessor">#include <avr/signal.h></span>00021 00022 <span class="preprocessor">#include "<a class="code" href="global_8h.html">global.h</a>"</span>00023 <span class="preprocessor">#include "<a class="code" href="timer_8h.html">timer.h</a>"</span>00024 <span class="preprocessor">#include "<a class="code" href="uartsw2_8h.html">uartsw2.h</a>"</span>00025 00026 <span class="comment">// Program ROM constants</span>00027 00028 <span class="comment">// Global variables</span>00029 00030 <span class="comment">// uartsw transmit status and data variables</span>00031 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswTxBusy;00032 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswTxData;00033 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswTxBitNum;00034 00035 <span class="comment">// baud rate common to transmit and receive</span>00036 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswBaudRateDiv;00037 00038 <span class="comment">// uartsw receive status and data variables</span>00039 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswRxBusy;00040 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswRxData;00041 <span class="keyword">static</span> <span class="keyword">volatile</span> u08 UartswRxBitNum;00042 <span class="comment">// receive buffer</span>00043 <span class="keyword">static</span> cBuffer uartswRxBuffer; <span class="comment">///< uartsw receive buffer</span>00044 <span class="comment"></span><span class="comment">// automatically allocate space in ram for each buffer</span>00045 <span class="keyword">static</span> <span class="keywordtype">char</span> uartswRxData[<a class="code" href="uartsw2conf_8h.html#a0">UARTSW_RX_BUFFER_SIZE</a>];00046 00047 <span class="comment">// functions</span>00048 <span class="comment"></span>00049 <span class="comment">//! enable and initialize the software uart</span><a name="l00050"></a><a class="code" href="uartsw2_8c.html#a9">00050</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>)00051 {00052 <span class="comment">// initialize the buffers</span>00053 <a class="code" href="uartsw_8c.html#a10">uartswInitBuffers</a>();00054 <span class="comment">// initialize the ports</span>00055 sbi(<a class="code" href="uartsw2conf_8h.html#a2">UARTSW_TX_DDR</a>, <a class="code" href="uartsw2conf_8h.html#a3">UARTSW_TX_PIN</a>);00056 cbi(<a class="code" href="uartsw2conf_8h.html#a5">UARTSW_RX_DDR</a>, <a class="code" href="uartsw2conf_8h.html#a7">UARTSW_RX_PIN</a>);00057 cbi(<a class="code" href="uartsw2conf_8h.html#a4">UARTSW_RX_PORT</a>, <a class="code" href="uartsw2conf_8h.html#a7">UARTSW_RX_PIN</a>);00058 <span class="comment">// initialize baud rate</span>00059 <a class="code" href="uartsw2_8h.html#a4">uartswSetBaudRate</a>(9600);00060 00061 <span class="comment">// setup the transmitter</span>00062 UartswTxBusy = FALSE;00063 <span class="comment">// disable OC2 interrupt</span>00064 cbi(TIMSK, OCIE2);00065 <span class="comment">// attach TxBit service routine to OC2</span>00066 <a class="code" href="timer128_8h.html#a52">timerAttach</a>(TIMER2OUTCOMPARE_INT, <a class="code" href="uartsw_8c.html#a16">uartswTxBitService</a>);00067 00068 <span class="comment">// setup the receiver</span>00069 UartswRxBusy = FALSE;00070 <span class="comment">// disable OC0 interrupt</span>00071 cbi(TIMSK, OCIE0);00072 <span class="comment">// attach RxBit service routine to OC0</span>00073 <a class="code" href="timer128_8h.html#a52">timerAttach</a>(TIMER0OUTCOMPARE_INT, <a class="code" href="uartsw_8c.html#a17">uartswRxBitService</a>);00074 <span class="comment">// INT2 trigger on rising edge</span>00075 sbi(MCUCSR, ISC2);00076 <span class="comment">// enable INT2 interrupt</span>00077 sbi(GICR, INT2);00078 00079 <span class="comment">// turn on interrupts</span>00080 sei();00081 }00082 <span class="comment"></span>00083 <span class="comment">//! create and initialize the uart buffers</span><a name="l00084"></a><a class="code" href="uartsw2_8c.html#a10">00084</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>)00085 {00086 <span class="comment">// initialize the UART receive buffer</span>00087 <a class="code" href="buffer_8h.html#a1">bufferInit</a>(&uartswRxBuffer, uartswRxData, <a class="code" href="uartsw2conf_8h.html#a0">UARTSW_RX_BUFFER_SIZE</a>);00088 }00089 <span class="comment"></span>00090 <span class="comment">//! turns off software UART</span><a name="l00091"></a><a class="code" href="uartsw2_8c.html#a11">00091</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>)00092 {00093 <span class="comment">// disable interrupts</span>00094 cbi(TIMSK, OCIE2);00095 cbi(TIMSK, OCIE0);00096 cbi(GICR, INT2);00097 <span class="comment">// detach the service routines</span>00098 <a class="code" href="timer128_8h.html#a53">timerDetach</a>(TIMER2OUTCOMPARE_INT);00099 <a class="code" href="timer128_8h.html#a53">timerDetach</a>(TIMER0OUTCOMPARE_INT);00100 }00101 <a name="l00102"></a><a class="code" href="uartsw2_8c.html#a12">00102</a> <span class="keywordtype">void</span> <a class="code" href="uartsw2_8h.html#a4">uartswSetBaudRate</a>(u32 baudrate)00103 {00104 u16 div;00105 00106 <span class="comment">// set timer prescaler</span>00107 <span class="keywordflow">if</span>( baudrate > (F_CPU/64L*256L) )00108 {00109 <span class="comment">// if the requested baud rate is high,</span>00110 <span class="comment">// set timer prescalers to div-by-64</span>00111 <a class="code" href="timer128_8h.html#a46">timer2SetPrescaler</a>(<a class="code" href="timer_8h.html#a15">TIMERRTC_CLK_DIV64</a>);00112 <a class="code" href="timer128_8h.html#a44">timer0SetPrescaler</a>(<a class="code" href="timer_8h.html#a5">TIMER_CLK_DIV64</a>);00113 div = 64;00114 }00115 <span class="keywordflow">else</span>00116 {00117 <span class="comment">// if the requested baud rate is low,</span>00118 <span class="comment">// set timer prescalers to div-by-256</span>00119 <a class="code" href="timer128_8h.html#a46">timer2SetPrescaler</a>(<a class="code" href="timer_8h.html#a17">TIMERRTC_CLK_DIV256</a>);00120 <a class="code" href="timer128_8h.html#a44">timer0SetPrescaler</a>(<a class="code" href="timer_8h.html#a6">TIMER_CLK_DIV256</a>);00121 div = 256;00122 }00123 00124 <span class="comment">// calculate division factor for requested baud rate, and set it</span>00125 <span class="comment">//UartswBaudRateDiv = (u08)(((F_CPU/64L)+(baudrate/2L))/(baudrate*1L));</span>00126 <span class="comment">//UartswBaudRateDiv = (u08)(((F_CPU/256L)+(baudrate/2L))/(baudrate*1L));</span>00127 UartswBaudRateDiv = (u08)(((F_CPU/div)+(baudrate/2L))/(baudrate*1L));00128 }00129 <span class="comment"></span>00130 <span class="comment">//! returns the receive buffer structure </span><a name="l00131"></a><a class="code" href="uartsw2_8c.html#a13">00131</a> <span class="comment"></span>cBuffer* <a class="code" href="uartsw_8c.html#a13">uartswGetRxBuffer</a>(<span class="keywordtype">void</span>)00132 {00133 <span class="comment">// return rx buffer pointer</span>00134 <span class="keywordflow">return</span> &uartswRxBuffer;00135 }00136 <a name="l00137"></a><a class="code" href="uartsw2_8c.html#a14">00137</a> <span class="keywordtype">void</span> <a class="code" href="uartsw2_8h.html#a5">uartswSendByte</a>(u08 data)00138 {00139 <span class="comment">// wait until uart is ready</span>00140 <span class="keywordflow">while</span>(UartswTxBusy);00141 <span class="comment">// set busy flag</span>00142 UartswTxBusy = TRUE;⌨️ 快捷键说明
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