i2c_8c-source.html

avr应用测试程序

00199     <span class="keywordflow">while</span>(I2cState);
00200     <span class="comment">// return data</span>
00201     <span class="keywordflow">for</span>(i=0; i&lt;length; i++)
00202         *data++ = I2cReceiveData[i];
00203 }
00204 
<a name="l00205"></a><a class="code" href="i2c_8h.html#a52">00205</a> u08 <a class="code" href="i2c_8c.html#a24">i2cMasterSendNI</a>(u08 deviceAddr, u08 length, u08* data)
00206 {
00207     u08 retval = I2C_OK;
00208 
00209     <span class="comment">// disable TWI interrupt</span>
00210     cbi(TWCR, TWIE);
00211 
00212     <span class="comment">// send start condition</span>
00213     <a class="code" href="i2c_8c.html#a15">i2cSendStart</a>();
00214     <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00215 
00216     <span class="comment">// send device address with write</span>
00217     <a class="code" href="i2c_8c.html#a18">i2cSendByte</a>( deviceAddr &amp; 0xFE );
00218     <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00219 
00220     <span class="comment">// check if device is present and live</span>
00221     <span class="keywordflow">if</span>( inb(TWSR) == TW_MT_SLA_ACK)
00222     {
00223         <span class="comment">// send data</span>
00224         <span class="keywordflow">while</span>(length)
00225         {
00226             <a class="code" href="i2c_8c.html#a18">i2cSendByte</a>( *data++ );
00227             <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00228             length--;
00229         }
00230     }
00231     <span class="keywordflow">else</span>
00232     {
00233         <span class="comment">// device did not ACK it's address,</span>
00234         <span class="comment">// data will not be transferred</span>
00235         <span class="comment">// return error</span>
00236         retval = I2C_ERROR_NODEV;
00237     }
00238 
00239     <span class="comment">// transmit stop condition</span>
00240     <span class="comment">// leave with TWEA on for slave receiving</span>
00241     <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00242     <span class="keywordflow">while</span>( !(inb(TWCR) &amp; BV(TWSTO)) );
00243 
00244     <span class="comment">// enable TWI interrupt</span>
00245     sbi(TWCR, TWIE);
00246 
00247     <span class="keywordflow">return</span> retval;
00248 }
00249 
<a name="l00250"></a><a class="code" href="i2c_8h.html#a53">00250</a> u08 <a class="code" href="i2c_8c.html#a25">i2cMasterReceiveNI</a>(u08 deviceAddr, u08 length, u08 *data)
00251 {
00252     u08 retval = I2C_OK;
00253 
00254     <span class="comment">// disable TWI interrupt</span>
00255     cbi(TWCR, TWIE);
00256 
00257     <span class="comment">// send start condition</span>
00258     <a class="code" href="i2c_8c.html#a15">i2cSendStart</a>();
00259     <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00260 
00261     <span class="comment">// send device address with read</span>
00262     <a class="code" href="i2c_8c.html#a18">i2cSendByte</a>( deviceAddr | 0x01 );
00263     <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00264 
00265     <span class="comment">// check if device is present and live</span>
00266     <span class="keywordflow">if</span>( inb(TWSR) == TW_MR_SLA_ACK)
00267     {
00268         <span class="comment">// accept receive data and ack it</span>
00269         <span class="keywordflow">while</span>(length &gt; 1)
00270         {
00271             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(TRUE);
00272             <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00273             *data++ = <a class="code" href="i2c_8c.html#a20">i2cGetReceivedByte</a>();
00274             <span class="comment">// decrement length</span>
00275             length--;
00276         }
00277 
00278         <span class="comment">// accept receive data and nack it (last-byte signal)</span>
00279         <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00280         <a class="code" href="i2c_8c.html#a17">i2cWaitForComplete</a>();
00281         *data++ = <a class="code" href="i2c_8c.html#a20">i2cGetReceivedByte</a>();
00282     }
00283     <span class="keywordflow">else</span>
00284     {
00285         <span class="comment">// device did not ACK it's address,</span>
00286         <span class="comment">// data will not be transferred</span>
00287         <span class="comment">// return error</span>
00288         retval = I2C_ERROR_NODEV;
00289     }
00290 
00291     <span class="comment">// transmit stop condition</span>
00292     <span class="comment">// leave with TWEA on for slave receiving</span>
00293     <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00294 
00295     <span class="comment">// enable TWI interrupt</span>
00296     sbi(TWCR, TWIE);
00297 
00298     <span class="keywordflow">return</span> retval;
00299 }
00300 <span class="comment">/*</span>
00301 <span class="comment">void i2cMasterTransferNI(u08 deviceAddr, u08 sendlength, u08* senddata, u08 receivelength, u08* receivedata)</span>
00302 <span class="comment">{</span>
00303 <span class="comment">    // disable TWI interrupt</span>
00304 <span class="comment">    cbi(TWCR, TWIE);</span>
00305 <span class="comment"></span>
00306 <span class="comment">    // send start condition</span>
00307 <span class="comment">    i2cSendStart();</span>
00308 <span class="comment">    i2cWaitForComplete();</span>
00309 <span class="comment"></span>
00310 <span class="comment">    // if there's data to be sent, do it</span>
00311 <span class="comment">    if(sendlength)</span>
00312 <span class="comment">    {</span>
00313 <span class="comment">        // send device address with write</span>
00314 <span class="comment">        i2cSendByte( deviceAddr &amp; 0xFE );</span>
00315 <span class="comment">        i2cWaitForComplete();</span>
00316 <span class="comment">        </span>
00317 <span class="comment">        // send data</span>
00318 <span class="comment">        while(sendlength)</span>
00319 <span class="comment">        {</span>
00320 <span class="comment">            i2cSendByte( *senddata++ );</span>
00321 <span class="comment">            i2cWaitForComplete();</span>
00322 <span class="comment">            sendlength--;</span>
00323 <span class="comment">        }</span>
00324 <span class="comment">    }</span>
00325 <span class="comment"></span>
00326 <span class="comment">    // if there's data to be received, do it</span>
00327 <span class="comment">    if(receivelength)</span>
00328 <span class="comment">    {</span>
00329 <span class="comment">        // send repeated start condition</span>
00330 <span class="comment">        i2cSendStart();</span>
00331 <span class="comment">        i2cWaitForComplete();</span>
00332 <span class="comment"></span>
00333 <span class="comment">        // send device address with read</span>
00334 <span class="comment">        i2cSendByte( deviceAddr | 0x01 );</span>
00335 <span class="comment">        i2cWaitForComplete();</span>
00336 <span class="comment"></span>
00337 <span class="comment">        // accept receive data and ack it</span>
00338 <span class="comment">        while(receivelength &gt; 1)</span>
00339 <span class="comment">        {</span>
00340 <span class="comment">            i2cReceiveByte(TRUE);</span>
00341 <span class="comment">            i2cWaitForComplete();</span>
00342 <span class="comment">            *receivedata++ = i2cGetReceivedByte();</span>
00343 <span class="comment">            // decrement length</span>
00344 <span class="comment">            receivelength--;</span>
00345 <span class="comment">        }</span>
00346 <span class="comment"></span>
00347 <span class="comment">        // accept receive data and nack it (last-byte signal)</span>
00348 <span class="comment">        i2cReceiveByte(TRUE);</span>
00349 <span class="comment">        i2cWaitForComplete();</span>
00350 <span class="comment">        *receivedata++ = i2cGetReceivedByte();</span>
00351 <span class="comment">    }</span>
00352 <span class="comment">    </span>
00353 <span class="comment">    // transmit stop condition</span>
00354 <span class="comment">    // leave with TWEA on for slave receiving</span>
00355 <span class="comment">    i2cSendStop();</span>
00356 <span class="comment">    while( !(inb(TWCR) &amp; BV(TWSTO)) );</span>
00357 <span class="comment"></span>
00358 <span class="comment">    // enable TWI interrupt</span>
00359 <span class="comment">    sbi(TWCR, TWIE);</span>
00360 <span class="comment">}</span>
00361 <span class="comment">*/</span>
00362 <span class="comment"></span>
00363 <span class="comment">//! I2C (TWI) interrupt service routine</span>
<a name="l00364"></a><a class="code" href="i2c_8c.html#a26">00364</a> <span class="comment"></span><a class="code" href="a2d_8c.html#a10">SIGNAL</a>(SIG_2WIRE_SERIAL)
00365 {
00366     <span class="comment">// read status bits</span>
00367     u08 status = inb(TWSR) &amp; TWSR_STATUS_MASK;
00368 
00369     <span class="keywordflow">switch</span>(status)
00370     {
00371     <span class="comment">// Master General</span>
00372     <span class="keywordflow">case</span> TW_START:                      <span class="comment">// 0x08: Sent start condition</span>
00373     <span class="keywordflow">case</span> TW_REP_START:                  <span class="comment">// 0x10: Sent repeated start condition</span>
00374 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00375 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00376         rprintf(<span class="stringliteral">"I2C: M-&gt;START\r\n"</span>);
00377         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00378 <span class="preprocessor">        #endif</span>
00379 <span class="preprocessor"></span>        <span class="comment">// send device address</span>
00380         <a class="code" href="i2c_8c.html#a18">i2cSendByte</a>(I2cDeviceAddrRW);
00381         <span class="keywordflow">break</span>;
00382     
00383     <span class="comment">// Master Transmitter &amp; Receiver status codes</span>
00384     <span class="keywordflow">case</span> TW_MT_SLA_ACK:                 <span class="comment">// 0x18: Slave address acknowledged</span>
00385     <span class="keywordflow">case</span> TW_MT_DATA_ACK:                <span class="comment">// 0x28: Data acknowledged</span>
00386 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00387 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00388         rprintf(<span class="stringliteral">"I2C: MT-&gt;SLA_ACK or DATA_ACK\r\n"</span>);
00389         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00390 <span class="preprocessor">        #endif</span>
00391 <span class="preprocessor"></span>        <span class="keywordflow">if</span>(I2cSendDataIndex &lt; I2cSendDataLength)
00392         {
00393             <span class="comment">// send data</span>
00394             <a class="code" href="i2c_8c.html#a18">i2cSendByte</a>( I2cSendData[I2cSendDataIndex++] );
00395         }
00396         <span class="keywordflow">else</span>
00397         {
00398             <span class="comment">// transmit stop condition, enable SLA ACK</span>
00399             <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00400             <span class="comment">// set state</span>
00401             I2cState = I2C_IDLE;
00402         }
00403         <span class="keywordflow">break</span>;