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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 ARMlib-LPC2100: i2c.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="files.html">File List</a> | <a class="qindex" href="globals.html">Globals</a></div><h1>i2c.c</h1><a href="i2c_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre>00001 <span class="comment">/*! \file i2c.c \brief I2C interface using Philips LPC internal I2C hardware. */</span>00002 <span class="comment">//*****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'i2c.c'</span>00005 <span class="comment">// Title : I2C interface using Philips LPC internal I2C hardware</span>00006 <span class="comment">// Author : Pascal Stang - Copyright (C) 2004</span>00007 <span class="comment">// Created : 2004.05.05</span>00008 <span class="comment">// Revised : 2004.07.12</span>00009 <span class="comment">// Version : 0.9</span>00010 <span class="comment">// Target MCU : ARM, Philips LPC2100-series</span>00011 <span class="comment">// Editor Tabs : 4</span>00012 <span class="comment">//</span>00013 <span class="comment">// Description : I2C (pronounced "eye-squared-see") is a two-wire bidirectional</span>00014 <span class="comment">// network designed for easy transfer of information between a wide variety</span>00015 <span class="comment">// of intelligent devices. Many of the Atmel AVR series processors have</span>00016 <span class="comment">// hardware support for transmitting and receiving using an I2C-type bus.</span>00017 <span class="comment">// In addition to the AVRs, there are thousands of other parts made by</span>00018 <span class="comment">// manufacturers like Philips, Maxim, National, TI, etc that use I2C as</span>00019 <span class="comment">// their primary means of communication and control. Common device types</span>00020 <span class="comment">// are A/D & D/A converters, temp sensors, intelligent battery monitors,</span>00021 <span class="comment">// MP3 decoder chips, EEPROM chips, multiplexing switches, etc.</span>00022 <span class="comment">//</span>00023 <span class="comment">// I2C uses only two wires (SDA and SCL) to communicate bidirectionally</span>00024 <span class="comment">// between devices. I2C is a multidrop network, meaning that you can have</span>00025 <span class="comment">// several devices on a single bus. Because I2C uses a 7-bit number to</span>00026 <span class="comment">// identify which device it wants to talk to, you cannot have more than</span>00027 <span class="comment">// 127 devices on a single bus.</span>00028 <span class="comment">//</span>00029 <span class="comment">// I2C ordinarily requires two 4.7K pull-up resistors to power (one each on</span>00030 <span class="comment">// SDA and SCL), but for small numbers of devices (maybe 1-4), it is enough</span>00031 <span class="comment">// to activate the internal pull-up resistors in the AVR processor. To do</span>00032 <span class="comment">// this, set the port pins, which correspond to the I2C pins SDA/SCL, high.</span>00033 <span class="comment">// For example, on the mega163, sbi(PORTC, 0); sbi(PORTC, 1);.</span>00034 <span class="comment">//</span>00035 <span class="comment">// For complete information about I2C, see the Philips Semiconductor</span>00036 <span class="comment">// website. They created I2C and have the largest family of devices that</span>00037 <span class="comment">// work with I2C.</span>00038 <span class="comment">//</span>00039 <span class="comment">// Note: Many manufacturers market I2C bus devices under a different or generic</span>00040 <span class="comment">// bus name like "Two-Wire Interface". This is because Philips still holds</span>00041 <span class="comment">// "I2C" as a trademark. For example, SMBus and SMBus devices are hardware</span>00042 <span class="comment">// compatible and closely related to I2C. They can be directly connected</span>00043 <span class="comment">// to an I2C bus along with other I2C devices are are generally accessed in</span>00044 <span class="comment">// the same way as I2C devices. SMBus is often found on modern motherboards</span>00045 <span class="comment">// for temp sensing and other low-level control tasks.</span>00046 <span class="comment">//</span>00047 <span class="comment">// This code is distributed under the GNU Public License</span>00048 <span class="comment">// which can be found at http://www.gnu.org/licenses/gpl.txt</span>00049 <span class="comment">//</span>00050 <span class="comment">//*****************************************************************************</span>00051 00052 <span class="preprocessor">#include "lpc210x.h"</span>00053 <span class="preprocessor">#include "config.h"</span>00054 <span class="preprocessor">#include "<a class="code" href="global_8h.html">global.h</a>"</span>00055 <span class="preprocessor">#include "<a class="code" href="timer_8h.html">timer.h</a>"</span>00056 <span class="preprocessor">#include "<a class="code" href="i2c_8h.html">i2c.h</a>"</span>00057 <a name="l00058"></a><a class="code" href="i2c_8h.html#a43">00058</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8c.html#a0">i2cInit</a>(<span class="keywordtype">void</span>)00059 {00060 <span class="comment">// setup SCL pin P02</span>00061 PINSEL0 &= ~(3<<4);00062 PINSEL0 |= 1<<4;00063 <span class="comment">// setup SDA pin P03</span>00064 PINSEL0 &= ~(3<<6);00065 PINSEL0 |= 1<<6;00066 00067 <span class="comment">// set default bitrate of 100KHz</span>00068 <a class="code" href="i2c_8h.html#a44">i2cSetBitrate</a>(400);00069 00070 <span class="comment">// disable and reset interface</span>00071 I2CONCLR = 0xFF;00072 delay(10);00073 00074 <span class="comment">// enable interface</span>00075 I2CONSET = BIT(I2CON_I2EN);00076 }00077 <span class="comment">/*</span>00078 <span class="comment">void InitialiseI2C(void)</span>00079 <span class="comment">{</span>00080 <span class="comment"></span>00081 <span class="comment">REG(I2C_I2SCLL) = 0x18;</span>00082 <span class="comment"></span>00083 <span class="comment">REG(I2C_I2SCLH) = 0x18;</span>00084 <span class="comment"></span>00085 <span class="comment">REG(I2C_I2CONCLR) = 0xFF;</span>00086 <span class="comment"></span>00087 <span class="comment">// Set pinouts as scl and sda</span>00088 <span class="comment">REG(PCB_PINSEL0) = 0x50;</span>00089 <span class="comment"></span>00090 <span class="comment">REG(I2C_I2CONSET) = 0x40;</span>00091 <span class="comment">delay(10);</span>00092 <span class="comment">REG(I2C_I2CONSET) = 0x64;</span>00093 <span class="comment"></span>00094 <span class="comment">REG(I2C_I2DAT) = 0x42;</span>00095 <span class="comment"></span>00096 <span class="comment">REG(I2C_I2CONCLR) = 0x08;</span>00097 <span class="comment"></span>00098 <span class="comment">REG(I2C_I2CONCLR) = 0x20;</span>00099 <span class="comment"></span>00100 <span class="comment">}</span>00101 <span class="comment">*/</span>00102 <a name="l00103"></a><a class="code" href="i2c_8h.html#a44">00103</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8h.html#a44">i2cSetBitrate</a>(u16 bitrateDiv)00104 {00105 <span class="comment">// @60MHz and VPB=2, set to 75 for 400KHz</span>00106 <span class="comment">// @60MHz and VPB=2, set to 400 for 75KHz</span>00107 I2SCLL = bitrateDiv;00108 I2SCLH = bitrateDiv;00109 }00110 <a name="l00111"></a><a class="code" href="i2c_8h.html#a45">00111</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8h.html#a45">i2cSetLocalDeviceAddr</a>(u08 deviceAddr, u08 genCallEn)00112 {00113 <span class="comment">// set local device address (used in slave mode only)</span>00114 I2ADR = ((deviceAddr&0xFE) | (genCallEn?1:0));00115 }00116 <a name="l00117"></a><a class="code" href="i2c_8h.html#a46">00117</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8c.html#a3">i2cSendStart</a>(<span class="keywordtype">void</span>)00118 {00119 I2CONSET = BIT(I2CON_STA);00120 I2CONCLR = BIT(I2CON_SI);00121 }00122 <a name="l00123"></a><a class="code" href="i2c_8h.html#a47">00123</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8c.html#a4">i2cSendStop</a>(<span class="keywordtype">void</span>)00124 {00125 I2CONSET = BIT(I2CON_STO);00126 }00127 <a name="l00128"></a><a class="code" href="i2c_8h.html#a48">00128</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>(<span class="keywordtype">void</span>)00129 {00130 <span class="comment">// wait for a valid status code</span>00131 <span class="keywordflow">while</span>(I2STAT == TW_NO_INFO);00132 }00133 <a name="l00134"></a><a class="code" href="i2c_8h.html#a49">00134</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8h.html#a49">i2cSendByte</a>(u08 data)00135 {⌨️ 快捷键说明
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