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方便飞利浦arm7tdmi 处理器lpc2100开发的C函数库 Procyon ARMlib-LPC2100 C-Language Function Library for Philips LPC21

00136     <span class="comment">// save data into data register</span>
00137     I2DAT = data;
00138     <span class="comment">// clear SI bit to begin transfer</span>
00139     I2CONCLR = BIT(I2CON_SI);
00140 }
00141 
<a name="l00142"></a><a class="code" href="i2c_8h.html#a50">00142</a> <span class="keywordtype">void</span> <a class="code" href="i2c_8h.html#a50">i2cReceiveByte</a>(u08 ackFlag)
00143 {
00144     <span class="comment">// begin receive over i2c</span>
00145     <span class="keywordflow">if</span>( ackFlag )
00146     {
00147         <span class="comment">// ackFlag = TRUE: ACK the recevied data</span>
00148         I2CONSET = BIT(I2CON_AA);
00149         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));</span>
00150     }
00151     <span class="keywordflow">else</span>
00152     {
00153         <span class="comment">// ackFlag = FALSE: NACK the recevied data</span>
00154         I2CONCLR = BIT(I2CON_AA);
00155         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00156     }
00157     <span class="comment">// clear SI bit to begin transfer</span>
00158     I2CONCLR = BIT(I2CON_SI);
00159 }
00160 
<a name="l00161"></a><a class="code" href="i2c_8h.html#a51">00161</a> u08 <a class="code" href="i2c_8c.html#a8">i2cGetReceivedByte</a>(<span class="keywordtype">void</span>)
00162 {
00163     <span class="keywordflow">return</span> I2DAT;
00164 }
00165 
<a name="l00166"></a><a class="code" href="i2c_8h.html#a52">00166</a> u08 <a class="code" href="i2c_8c.html#a9">i2cGetStatus</a>(<span class="keywordtype">void</span>)
00167 {
00168     <span class="keywordflow">return</span> I2STAT;
00169 }
00170 
00171 
<a name="l00172"></a><a class="code" href="i2c_8h.html#a53">00172</a> u08 <a class="code" href="i2c_8h.html#a53">i2cMasterSendNI</a>(u08 deviceAddr, u08 length, u08* data)
00173 {
00174     u08 retval = I2C_OK;
00175 
00176     <span class="comment">// disable TWI interrupt</span>
00177     <span class="comment">//cbi(TWCR, TWIE);</span>
00178 
00179     <span class="comment">// send start condition</span>
00180     <a class="code" href="i2c_8c.html#a3">i2cSendStart</a>();
00181     <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00182     I2CONCLR = BIT(I2CON_STA);
00183 
00184     <span class="comment">// send device address with write</span>
00185     <a class="code" href="i2c_8h.html#a49">i2cSendByte</a>( deviceAddr &amp; 0xFE );
00186     <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00187 
00188     <span class="comment">// check if device is present and live</span>
00189     <span class="keywordflow">if</span>( I2STAT == TW_MT_SLA_ACK)
00190     {
00191         <span class="comment">// send data</span>
00192         <span class="keywordflow">while</span>(length)
00193         {
00194             <a class="code" href="i2c_8h.html#a49">i2cSendByte</a>( *data++ );
00195             <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00196             length--;
00197         }
00198     }
00199     <span class="keywordflow">else</span>
00200     {
00201         <span class="comment">// device did not ACK it's address,</span>
00202         <span class="comment">// data will not be transferred</span>
00203         <span class="comment">// return error</span>
00204         retval = I2C_ERROR_NODEV;
00205     }
00206 
00207     <span class="comment">// transmit stop condition</span>
00208     <span class="comment">// leave with TWEA on for slave receiving</span>
00209     I2CONSET = BIT(I2CON_STA);
00210     delay(10);
00211     I2CONCLR = BIT(I2CON_STO);
00212     <span class="comment">//while( !(inb(TWCR) &amp; BV(TWSTO)) );</span>
00213 
00214     <span class="comment">// enable TWI interrupt</span>
00215     <span class="comment">//sbi(TWCR, TWIE);</span>
00216 
00217     <span class="keywordflow">return</span> retval;
00218 }
00219 
<a name="l00220"></a><a class="code" href="i2c_8h.html#a54">00220</a> u08 <a class="code" href="i2c_8h.html#a54">i2cMasterReceiveNI</a>(u08 deviceAddr, u08 length, u08 *data)
00221 {
00222     u08 retval = I2C_OK;
00223 
00224     <span class="comment">// disable TWI interrupt</span><span class="comment"></span>
00225 <span class="comment">    ///cbi(TWCR, TWIE);</span>
00226 <span class="comment"></span>
00227     <span class="comment">// send start condition</span>
00228     <a class="code" href="i2c_8c.html#a3">i2cSendStart</a>();
00229     <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00230 
00231     <span class="comment">// send device address with read</span>
00232     <a class="code" href="i2c_8h.html#a49">i2cSendByte</a>( deviceAddr | 0x01 );
00233     <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00234 
00235     <span class="comment">// check if device is present and live</span>
00236     <span class="keywordflow">if</span>( I2STAT == TW_MR_SLA_ACK)
00237     {
00238         <span class="comment">// accept receive data and ack it</span>
00239         <span class="keywordflow">while</span>(length &gt; 1)
00240         {
00241             <a class="code" href="i2c_8h.html#a50">i2cReceiveByte</a>(TRUE);
00242             <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00243             *data++ = <a class="code" href="i2c_8c.html#a8">i2cGetReceivedByte</a>();
00244             <span class="comment">// decrement length</span>
00245             length--;
00246         }
00247 
00248         <span class="comment">// accept receive data and nack it (last-byte signal)</span>
00249         <a class="code" href="i2c_8h.html#a50">i2cReceiveByte</a>(FALSE);
00250         <a class="code" href="i2c_8c.html#a5">i2cWaitForComplete</a>();
00251         *data++ = <a class="code" href="i2c_8c.html#a8">i2cGetReceivedByte</a>();
00252     }
00253     <span class="keywordflow">else</span>
00254     {
00255         <span class="comment">// device did not ACK it's address,</span>
00256         <span class="comment">// data will not be transferred</span>
00257         <span class="comment">// return error</span>
00258         retval = I2C_ERROR_NODEV;
00259     }
00260 
00261     <span class="comment">// transmit stop condition</span>
00262     <span class="comment">// leave with TWEA on for slave receiving</span>
00263     <a class="code" href="i2c_8c.html#a4">i2cSendStop</a>();
00264 
00265     <span class="comment">// enable TWI interrupt</span>
00266     <span class="comment">//sbi(TWCR, TWIE);</span>
00267 
00268     <span class="keywordflow">return</span> retval;
00269 }
00270 
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