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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: spi.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>spi.c</h1><a href="spi_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/*! \file spi.c \brief SPI interface driver. */</span>00002 <span class="comment">//*****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'spi.c'</span>00005 <span class="comment">// Title : SPI interface driver</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 : 06/06/2002</span>00009 <span class="comment">// Version : 0.6</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">// NOTE: This code is currently below version 1.0, and therefore is considered</span>00014 <span class="comment">// to be lacking in some functionality or documentation, or may not be fully</span>00015 <span class="comment">// tested. Nonetheless, you can expect most functions to work.</span>00016 <span class="comment">//</span>00017 <span class="comment">// This code is distributed under the GNU Public License</span>00018 <span class="comment">// which can be found at http://www.gnu.org/licenses/gpl.txt</span>00019 <span class="comment">//</span>00020 <span class="comment">//*****************************************************************************</span>00021 00022 <span class="preprocessor">#include <avr/io.h></span>00023 <span class="preprocessor">#include <avr/interrupt.h></span>00024 00025 <span class="preprocessor">#include "<a class="code" href="spi_8h.html">spi.h</a>"</span>00026 00027 <span class="comment">// Define the SPI_USEINT key if you want SPI bus operation to be</span>00028 <span class="comment">// interrupt-driven. The primary reason for not using SPI in</span>00029 <span class="comment">// interrupt-driven mode is if the SPI send/transfer commands</span>00030 <span class="comment">// will be used from within some other interrupt service routine</span>00031 <span class="comment">// or if interrupts might be globally turned off due to of other</span>00032 <span class="comment">// aspects of your program</span>00033 <span class="comment">//</span>00034 <span class="comment">// Comment-out or uncomment this line as necessary</span>00035 <span class="comment">//#define SPI_USEINT</span>00036 00037 <span class="comment">// global variables</span>00038 <span class="keyword">volatile</span> u08 spiTransferComplete;00039 00040 <span class="comment">// SPI interrupt service handler</span>00041 <span class="preprocessor">#ifdef SPI_USEINT</span>00042 <span class="preprocessor"></span><a class="code" href="a2d_8c.html#a10">SIGNAL</a>(SIG_SPI)00043 {00044 spiTransferComplete = TRUE;00045 }00046 <span class="preprocessor">#endif</span>00047 <span class="preprocessor"></span>00048 <span class="comment">// access routines</span>00049 <span class="keywordtype">void</span> spiInit()00050 {00051 <span class="preprocessor">#ifdef __AVR_ATmega128__</span>00052 <span class="preprocessor"></span> <span class="comment">// setup SPI I/O pins</span>00053 sbi(PORTB, 1); <span class="comment">// set SCK hi</span>00054 sbi(DDRB, 1); <span class="comment">// set SCK as output</span>00055 cbi(DDRB, 3); <span class="comment">// set MISO as input</span>00056 sbi(DDRB, 2); <span class="comment">// set MOSI as output</span>00057 sbi(DDRB, 0); <span class="comment">// SS must be output for Master mode to work</span>00058 <span class="preprocessor">#elif __AVR_ATmega8__</span>00059 <span class="preprocessor"></span> <span class="comment">// setup SPI I/O pins</span>00060 sbi(PORTB, 5); <span class="comment">// set SCK hi</span>00061 sbi(DDRB, 5); <span class="comment">// set SCK as output</span>00062 cbi(DDRB, 4); <span class="comment">// set MISO as input</span>00063 sbi(DDRB, 3); <span class="comment">// set MOSI as output</span>00064 sbi(DDRB, 2); <span class="comment">// SS must be output for Master mode to work</span>00065 <span class="preprocessor">#else</span>00066 <span class="preprocessor"></span> <span class="comment">// setup SPI I/O pins</span>00067 sbi(PORTB, 7); <span class="comment">// set SCK hi</span>00068 sbi(DDRB, 7); <span class="comment">// set SCK as output</span>00069 cbi(DDRB, 6); <span class="comment">// set MISO as input</span>00070 sbi(DDRB, 5); <span class="comment">// set MOSI as output</span>00071 sbi(DDRB, 4); <span class="comment">// SS must be output for Master mode to work</span>00072 <span class="preprocessor">#endif</span>00073 <span class="preprocessor"></span> 00074 <span class="comment">// setup SPI interface :</span>00075 <span class="comment">// master mode</span>00076 sbi(SPCR, MSTR);00077 <span class="comment">// clock = f/4</span>00078 <span class="comment">// cbi(SPCR, SPR0);</span>00079 <span class="comment">// cbi(SPCR, SPR1);</span>00080 <span class="comment">// clock = f/16</span>00081 cbi(SPCR, SPR0);00082 sbi(SPCR, SPR1);00083 <span class="comment">// select clock phase positive-going in middle of data</span>00084 cbi(SPCR, CPOL);00085 <span class="comment">// Data order MSB first</span>00086 cbi(SPCR,DORD);00087 <span class="comment">// enable SPI</span>00088 sbi(SPCR, SPE);00089 00090 00091 <span class="comment">// some other possible configs</span>00092 <span class="comment">//outp((1<<MSTR)|(1<<SPE)|(1<<SPR0), SPCR );</span>00093 <span class="comment">//outp((1<<CPHA)|(1<<CPOL)|(1<<MSTR)|(1<<SPE)|(1<<SPR0)|(1<<SPR1), SPCR );</span>00094 <span class="comment">//outp((1<<CPHA)|(1<<MSTR)|(1<<SPE)|(1<<SPR0), SPCR );</span>00095 00096 <span class="comment">// clear status</span>00097 inb(SPSR);00098 spiTransferComplete = TRUE;00099 00100 <span class="comment">// enable SPI interrupt</span>00101 <span class="preprocessor"> #ifdef SPI_USEINT</span>00102 <span class="preprocessor"></span> sbi(SPCR, SPIE);00103 <span class="preprocessor"> #endif</span>00104 <span class="preprocessor"></span>}00105 <span class="comment">/*</span>00106 <span class="comment">void spiSetBitrate(u08 spr)</span>00107 <span class="comment">{</span>00108 <span class="comment"> outb(SPCR, (inb(SPCR) & ((1<<SPR0)|(1<<SPR1))) | (spr&((1<<SPR0)|(1<<SPR1)))));</span>00109 <span class="comment">}</span>00110 <span class="comment">*/</span>00111 <span class="keywordtype">void</span> spiSendByte(u08 data)00112 {00113 <span class="comment">// send a byte over SPI and ignore reply</span>00114 <span class="preprocessor"> #ifdef SPI_USEINT</span>00115 <span class="preprocessor"></span> <span class="keywordflow">while</span>(!spiTransferComplete);00116 spiTransferComplete = FALSE;00117 <span class="preprocessor"> #else</span>00118 <span class="preprocessor"></span> <span class="keywordflow">while</span>(!(inb(SPSR) & (1<<SPIF)));00119 <span class="preprocessor"> #endif</span>00120 <span class="preprocessor"></span>00121 outb(SPDR, data);00122 }00123 00124 u08 spiTransferByte(u08 data)00125 {00126 <span class="preprocessor"> #ifdef SPI_USEINT</span>00127 <span class="preprocessor"></span> <span class="comment">// send the given data</span>00128 spiTransferComplete = FALSE;00129 outb(SPDR, data);00130 <span class="comment">// wait for transfer to complete</span>00131 <span class="keywordflow">while</span>(!spiTransferComplete);00132 <span class="preprocessor"> #else</span>00133 <span class="preprocessor"></span> <span class="comment">// send the given data</span>00134 outb(SPDR, data);00135 <span class="comment">// wait for transfer to complete</span>00136 <span class="keywordflow">while</span>(!(inb(SPSR) & (1<<SPIF)));00137 <span class="preprocessor"> #endif</span>00138 <span class="preprocessor"></span> <span class="comment">// return the received data</span>00139 <span class="keywordflow">return</span> inb(SPDR);00140 }00141 00142 u16 spiTransferWord(u16 data)00143 {00144 u16 rxData = 0;00145 00146 <span class="comment">// send MS byte of given data</span>00147 rxData = (spiTransferByte((data>>8) & 0x00FF))<<8;00148 <span class="comment">// send LS byte of given data</span>00149 rxData |= (spiTransferByte(data & 0x00FF));00150 00151 <span class="comment">// return the received data</span>00152 <span class="keywordflow">return</span> rxData;00153 }</pre></div><hr size="1"><address style="align: right;"><small>Generated on Sun Oct 29 03:41:07 2006 for Procyon AVRlib by <a href="http://www.doxygen.org/index.html"><img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.4.2 </small></address></body></html>⌨️ 快捷键说明
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