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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: uart.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>uart.c</h1><a href="uart_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/*! \file uart.c \brief UART driver with buffer support. */</span>00002 <span class="comment">// *****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'uart.c'</span>00005 <span class="comment">// Title : UART driver with buffer support</span>00006 <span class="comment">// Author : Pascal Stang - Copyright (C) 2000-2002</span>00007 <span class="comment">// Created : 11/22/2000</span>00008 <span class="comment">// Revised : 06/09/2003</span>00009 <span class="comment">// Version : 1.3</span>00010 <span class="comment">// Target MCU : ATMEL AVR Series</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="buffer_8h.html">buffer.h</a>"</span>00022 <span class="preprocessor">#include "<a class="code" href="uart_8h.html">uart.h</a>"</span>00023 00024 <span class="comment">// UART global variables</span>00025 <span class="comment">// flag variables</span><a name="l00026"></a><a class="code" href="uart_8c.html#a0">00026</a> <span class="keyword">volatile</span> u08 <a class="code" href="uart_8c.html#a0">uartReadyTx</a>; <span class="comment">///< uartReadyTx flag</span><a name="l00027"></a><a class="code" href="uart_8c.html#a1">00027</a> <span class="comment"></span><span class="keyword">volatile</span> u08 <a class="code" href="uart_8c.html#a1">uartBufferedTx</a>; <span class="comment">///< uartBufferedTx flag</span>00028 <span class="comment"></span><span class="comment">// receive and transmit buffers</span><a name="l00029"></a><a class="code" href="uart_8c.html#a2">00029</a> <a class="code" href="structstruct__cBuffer.html">cBuffer</a> <a class="code" href="uart_8c.html#a2">uartRxBuffer</a>; <span class="comment">///< uart receive buffer</span><a name="l00030"></a><a class="code" href="uart_8c.html#a3">00030</a> <span class="comment"></span><a class="code" href="structstruct__cBuffer.html">cBuffer</a> <a class="code" href="uart_8c.html#a3">uartTxBuffer</a>; <span class="comment">///< uart transmit buffer</span><a name="l00031"></a><a class="code" href="uart_8c.html#a4">00031</a> <span class="comment"></span><span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> <a class="code" href="uart_8c.html#a4">uartRxOverflow</a>; <span class="comment">///< receive overflow counter</span>00032 <span class="comment"></span>00033 <span class="preprocessor">#ifndef UART_BUFFERS_EXTERNAL_RAM</span>00034 <span class="preprocessor"></span> <span class="comment">// using internal ram,</span>00035 <span class="comment">// automatically allocate space in ram for each buffer</span>00036 <span class="keyword">static</span> <span class="keywordtype">char</span> uartRxData[<a class="code" href="group__uart.html#ga16">UART_RX_BUFFER_SIZE</a>];00037 <span class="keyword">static</span> <span class="keywordtype">char</span> uartTxData[<a class="code" href="group__uart.html#ga15">UART_TX_BUFFER_SIZE</a>];00038 <span class="preprocessor">#endif</span>00039 <span class="preprocessor"></span>00040 <span class="keyword">typedef</span> void (*voidFuncPtru08)(<span class="keywordtype">unsigned</span> char);00041 <span class="keyword">volatile</span> <span class="keyword">static</span> voidFuncPtru08 UartRxFunc;00042 00043 <span class="comment">// enable and initialize the uart</span><a name="l00044"></a><a class="code" href="group__uart2.html#ga0">00044</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga0">uartInit</a>(<span class="keywordtype">void</span>)00045 {00046 <span class="comment">// initialize the buffers</span>00047 <a class="code" href="group__uart.html#ga1">uartInitBuffers</a>();00048 <span class="comment">// initialize user receive handler</span>00049 UartRxFunc = 0;00050 00051 <span class="comment">// enable RxD/TxD and interrupts</span>00052 outb(UCR, BV(RXCIE)|BV(TXCIE)|BV(RXEN)|BV(TXEN));00053 00054 <span class="comment">// set default baud rate</span>00055 <a class="code" href="group__uart.html#ga3">uartSetBaudRate</a>(<a class="code" href="group__uart.html#ga14">UART_DEFAULT_BAUD_RATE</a>); 00056 <span class="comment">// initialize states</span>00057 <a class="code" href="uart_8c.html#a0">uartReadyTx</a> = TRUE;00058 <a class="code" href="uart_8c.html#a1">uartBufferedTx</a> = FALSE;00059 <span class="comment">// clear overflow count</span>00060 <a class="code" href="uart_8c.html#a4">uartRxOverflow</a> = 0;00061 <span class="comment">// enable interrupts</span>00062 sei();00063 }00064 00065 <span class="comment">// create and initialize the uart transmit and receive buffers</span><a name="l00066"></a><a class="code" href="group__uart.html#ga1">00066</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga1">uartInitBuffers</a>(<span class="keywordtype">void</span>)00067 {00068 <span class="preprocessor"> #ifndef UART_BUFFERS_EXTERNAL_RAM</span>00069 <span class="preprocessor"></span> <span class="comment">// initialize the UART receive buffer</span>00070 <a class="code" href="group__buffer.html#ga1">bufferInit</a>(&uartRxBuffer, uartRxData, <a class="code" href="group__uart.html#ga16">UART_RX_BUFFER_SIZE</a>);00071 <span class="comment">// initialize the UART transmit buffer</span>00072 <a class="code" href="group__buffer.html#ga1">bufferInit</a>(&uartTxBuffer, uartTxData, <a class="code" href="group__uart.html#ga15">UART_TX_BUFFER_SIZE</a>);00073 <span class="preprocessor"> #else</span>00074 <span class="preprocessor"></span> <span class="comment">// initialize the UART receive buffer</span>00075 <a class="code" href="group__buffer.html#ga1">bufferInit</a>(&uartRxBuffer, (u08*) UART_RX_BUFFER_ADDR, <a class="code" href="group__uart.html#ga16">UART_RX_BUFFER_SIZE</a>);00076 <span class="comment">// initialize the UART transmit buffer</span>00077 <a class="code" href="group__buffer.html#ga1">bufferInit</a>(&uartTxBuffer, (u08*) UART_TX_BUFFER_ADDR, <a class="code" href="group__uart.html#ga15">UART_TX_BUFFER_SIZE</a>);00078 <span class="preprocessor"> #endif</span>00079 <span class="preprocessor"></span>}00080 00081 <span class="comment">// redirects received data to a user function</span><a name="l00082"></a><a class="code" href="group__uart.html#ga2">00082</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga2">uartSetRxHandler</a>(<span class="keywordtype">void</span> (*rx_func)(<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> c))00083 {00084 <span class="comment">// set the receive interrupt to run the supplied user function</span>00085 UartRxFunc = rx_func;00086 }00087 00088 <span class="comment">// set the uart baud rate</span><a name="l00089"></a><a class="code" href="group__uart.html#ga3">00089</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga3">uartSetBaudRate</a>(u32 baudrate)00090 {00091 <span class="comment">// calculate division factor for requested baud rate, and set it</span>00092 u16 bauddiv = ((F_CPU+(baudrate*8L))/(baudrate*16L)-1);00093 outb(UBRRL, bauddiv);00094 <span class="preprocessor"> #ifdef UBRRH</span>00095 <span class="preprocessor"></span> outb(UBRRH, bauddiv>>8);00096 <span class="preprocessor"> #endif</span>00097 <span class="preprocessor"></span>}00098 00099 <span class="comment">// returns the receive buffer structure </span><a name="l00100"></a><a class="code" href="group__uart.html#ga4">00100</a> <a class="code" href="structstruct__cBuffer.html">cBuffer</a>* <a class="code" href="group__uart.html#ga4">uartGetRxBuffer</a>(<span class="keywordtype">void</span>)00101 {00102 <span class="comment">// return rx buffer pointer</span>00103 <span class="keywordflow">return</span> &uartRxBuffer;00104 }00105 00106 <span class="comment">// returns the transmit buffer structure </span><a name="l00107"></a><a class="code" href="group__uart.html#ga5">00107</a> <a class="code" href="structstruct__cBuffer.html">cBuffer</a>* <a class="code" href="group__uart.html#ga5">uartGetTxBuffer</a>(<span class="keywordtype">void</span>)00108 {00109 <span class="comment">// return tx buffer pointer</span>00110 <span class="keywordflow">return</span> &uartTxBuffer;00111 }00112 00113 <span class="comment">// transmits a byte over the uart</span><a name="l00114"></a><a class="code" href="group__uart.html#ga6">00114</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga6">uartSendByte</a>(u08 txData)00115 {00116 <span class="comment">// wait for the transmitter to be ready</span>00117 <span class="keywordflow">while</span>(!<a class="code" href="uart_8c.html#a0">uartReadyTx</a>);00118 <span class="comment">// send byte</span>00119 outb(UDR, txData);00120 <span class="comment">// set ready state to FALSE</span>00121 <a class="code" href="uart_8c.html#a0">uartReadyTx</a> = FALSE;00122 }00123 00124 <span class="comment">// gets a single byte from the uart receive buffer (getchar-style)</span><a name="l00125"></a><a class="code" href="group__uart.html#ga7">00125</a> <span class="keywordtype">int</span> <a class="code" href="group__uart.html#ga7">uartGetByte</a>(<span class="keywordtype">void</span>)00126 {00127 u08 c;00128 <span class="keywordflow">if</span>(<a class="code" href="group__uart.html#ga8">uartReceiveByte</a>(&c))00129 <span class="keywordflow">return</span> c;00130 <span class="keywordflow">else</span>00131 <span class="keywordflow">return</span> -1;00132 }00133 00134 <span class="comment">// gets a byte (if available) from the uart receive buffer</span><a name="l00135"></a><a class="code" href="group__uart.html#ga8">00135</a> u08 <a class="code" href="group__uart.html#ga8">uartReceiveByte</a>(u08* rxData)00136 {00137 <span class="comment">// make sure we have a receive buffer</span>00138 <span class="keywordflow">if</span>(uartRxBuffer.<a class="code" href="structstruct__cBuffer.html#o1">size</a>)00139 {00140 <span class="comment">// make sure we have data</span>00141 <span class="keywordflow">if</span>(uartRxBuffer.<a class="code" href="structstruct__cBuffer.html#o2">datalength</a>)⌨️ 快捷键说明
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