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00404         <span class="keywordflow">break</span>;
00405     <span class="keywordflow">case</span> TW_MR_DATA_NACK:               <span class="comment">// 0x58: Data received, NACK reply issued</span>
00406 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00407 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00408         rprintf(<span class="stringliteral">"I2C: MR-&gt;DATA_NACK\r\n"</span>);
00409         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00410 <span class="preprocessor">        #endif</span>
00411 <span class="preprocessor"></span>        <span class="comment">// store final received data byte</span>
00412         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00413         <span class="comment">// continue to transmit STOP condition</span>
00414     <span class="keywordflow">case</span> TW_MR_SLA_NACK:                <span class="comment">// 0x48: Slave address not acknowledged</span>
00415     <span class="keywordflow">case</span> TW_MT_SLA_NACK:                <span class="comment">// 0x20: Slave address not acknowledged</span>
00416     <span class="keywordflow">case</span> TW_MT_DATA_NACK:               <span class="comment">// 0x30: Data not acknowledged</span>
00417 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00418 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00419         rprintf(<span class="stringliteral">"I2C: MTR-&gt;SLA_NACK or MT-&gt;DATA_NACK\r\n"</span>);
00420         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00421 <span class="preprocessor">        #endif</span>
00422 <span class="preprocessor"></span>        <span class="comment">// transmit stop condition, enable SLA ACK</span>
00423         <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00424         <span class="comment">// set state</span>
00425         I2cState = I2C_IDLE;
00426         <span class="keywordflow">break</span>;
00427     <span class="keywordflow">case</span> TW_MT_ARB_LOST:                <span class="comment">// 0x38: Bus arbitration lost</span>
00428     <span class="comment">//case TW_MR_ARB_LOST:              // 0x38: Bus arbitration lost</span>
00429 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00430 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00431         rprintf(<span class="stringliteral">"I2C: MT-&gt;ARB_LOST\r\n"</span>);
00432         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00433 <span class="preprocessor">        #endif</span>
00434 <span class="preprocessor"></span>        <span class="comment">// release bus</span>
00435         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));
00436         <span class="comment">// set state</span>
00437         I2cState = I2C_IDLE;
00438         <span class="comment">// release bus and transmit start when bus is free</span>
00439         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));</span>
00440         <span class="keywordflow">break</span>;
00441     <span class="keywordflow">case</span> TW_MR_DATA_ACK:                <span class="comment">// 0x50: Data acknowledged</span>
00442 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00443 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00444         rprintf(<span class="stringliteral">"I2C: MR-&gt;DATA_ACK\r\n"</span>);
00445         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00446 <span class="preprocessor">        #endif</span>
00447 <span class="preprocessor"></span>        <span class="comment">// store received data byte</span>
00448         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00449         <span class="comment">// fall-through to see if more bytes will be received</span>
00450     <span class="keywordflow">case</span> TW_MR_SLA_ACK:                 <span class="comment">// 0x40: Slave address acknowledged</span>
00451 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00452 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00453         rprintf(<span class="stringliteral">"I2C: MR-&gt;SLA_ACK\r\n"</span>);
00454         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00455 <span class="preprocessor">        #endif</span>
00456 <span class="preprocessor"></span>        <span class="keywordflow">if</span>(I2cReceiveDataIndex &lt; (I2cReceiveDataLength-1))
00457             <span class="comment">// data byte will be received, reply with ACK (more bytes in transfer)</span>
00458             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(TRUE);
00459         <span class="keywordflow">else</span>
00460             <span class="comment">// data byte will be received, reply with NACK (final byte in transfer)</span>
00461             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00462         <span class="keywordflow">break</span>;
00463 
00464     <span class="comment">// Slave Receiver status codes</span>
00465     <span class="keywordflow">case</span> TW_SR_SLA_ACK:                 <span class="comment">// 0x60: own SLA+W has been received, ACK has been returned</span>
00466     <span class="keywordflow">case</span> TW_SR_ARB_LOST_SLA_ACK:        <span class="comment">// 0x68: own SLA+W has been received, ACK has been returned</span>
00467     <span class="keywordflow">case</span> TW_SR_GCALL_ACK:               <span class="comment">// 0x70:     GCA+W has been received, ACK has been returned</span>
00468     <span class="keywordflow">case</span> TW_SR_ARB_LOST_GCALL_ACK:      <span class="comment">// 0x78:     GCA+W has been received, ACK has been returned</span>
00469 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00470 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00471         rprintf(<span class="stringliteral">"I2C: SR-&gt;SLA_ACK\r\n"</span>);
00472         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00473 <span class="preprocessor">        #endif</span>
00474 <span class="preprocessor"></span>        <span class="comment">// we are being addressed as slave for writing (data will be received from master)</span>
00475         <span class="comment">// set state</span>
00476         I2cState = I2C_SLAVE_RX;
00477         <span class="comment">// prepare buffer</span>
00478         I2cReceiveDataIndex = 0;
00479         <span class="comment">// receive data byte and return ACK</span>
00480         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00481         <span class="keywordflow">break</span>;
00482     <span class="keywordflow">case</span> TW_SR_DATA_ACK:                <span class="comment">// 0x80: data byte has been received, ACK has been returned</span>
00483     <span class="keywordflow">case</span> TW_SR_GCALL_DATA_ACK:          <span class="comment">// 0x90: data byte has been received, ACK has been returned</span>
00484 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00485 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00486         rprintf(<span class="stringliteral">"I2C: SR-&gt;DATA_ACK\r\n"</span>);
00487         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00488 <span class="preprocessor">        #endif</span>
00489 <span class="preprocessor"></span>        <span class="comment">// get previously received data byte</span>
00490         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00491         <span class="comment">// check receive buffer status</span>
00492         <span class="keywordflow">if</span>(I2cReceiveDataIndex &lt; I2C_RECEIVE_DATA_BUFFER_SIZE)
00493         {
00494             <span class="comment">// receive data byte and return ACK</span>
00495             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(TRUE);
00496             <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));</span>
00497         }
00498         <span class="keywordflow">else</span>
00499         {
00500             <span class="comment">// receive data byte and return NACK</span>
00501             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00502             <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00503         }
00504         <span class="keywordflow">break</span>;
00505     <span class="keywordflow">case</span> TW_SR_DATA_NACK:               <span class="comment">// 0x88: data byte has been received, NACK has been returned</span>
00506     <span class="keywordflow">case</span> TW_SR_GCALL_DATA_NACK:         <span class="comment">// 0x98: data byte has been received, NACK has been returned</span>
00507 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00508 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00509         rprintf(<span class="stringliteral">"I2C: SR-&gt;DATA_NACK\r\n"</span>);
00510         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00511 <span class="preprocessor">        #endif</span>
00512 <span class="preprocessor"></span>        <span class="comment">// receive data byte and return NACK</span>
00513         <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00514         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00515         <span class="keywordflow">break</span>;
00516     <span class="keywordflow">case</span> TW_SR_STOP:                    <span class="comment">// 0xA0: STOP or REPEATED START has been received while addressed as slave</span>
00517 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00518 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00519         rprintf(<span class="stringliteral">"I2C: SR-&gt;SR_STOP\r\n"</span>);
00520         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00521 <span class="preprocessor">        #endif</span>
00522 <span class="preprocessor"></span>        <span class="comment">// switch to SR mode with SLA ACK</span>
00523         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00524         <span class="comment">// i2c receive is complete, call i2cSlaveReceive</span>
00525         <span class="keywordflow">if</span>(i2cSlaveReceive) i2cSlaveReceive(I2cReceiveDataIndex, I2cReceiveData);
00526         <span class="comment">// set state</span>
00527         I2cState = I2C_IDLE;
00528         <span class="keywordflow">break</span>;
00529 
00530     <span class="comment">// Slave Transmitter</span>
00531     <span class="keywordflow">case</span> TW_ST_SLA_ACK:                 <span class="comment">// 0xA8: own SLA+R has been received, ACK has been returned</span>
00532     <span class="keywordflow">case</span> TW_ST_ARB_LOST_SLA_ACK:        <span class="comment">// 0xB0:     GCA+R has been received, ACK has been returned</span>
00533 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00534 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00535         rprintf(<span class="stringliteral">"I2C: ST-&gt;SLA_ACK\r\n"</span>);
00536         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00537 <span class="preprocessor">        #endif</span>
00538 <span class="preprocessor"></span>        <span class="comment">// we are being addressed as slave for reading (data must be transmitted back to master)</span>
00539         <span class="comment">// set state</span>
00540         I2cState = I2C_SLAVE_TX;
00541         <span class="comment">// request data from application</span>
00542         <span class="keywordflow">if</span>(i2cSlaveTransmit) I2cSendDataLength = i2cSlaveTransmit(I2C_SEND_DATA_BUFFER_SIZE, I2cSendData);
00543         <span class="comment">// reset data index</span>
00544         I2cSendDataIndex = 0;
00545         <span class="comment">// fall-through to transmit first data byte</span>
00546     <span class="keywordflow">case</span> TW_ST_DATA_ACK:                <span class="comment">// 0xB8: data byte has been transmitted, ACK has been received</span>
00547 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00548 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00549         rprintf(<span class="stringliteral">"I2C: ST-&gt;DATA_ACK\r\n"</span>);
00550         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00551 <span class="preprocessor">        #endif</span>
00552 <span class="preprocessor"></span>        <span class="comment">// transmit data byte</span>
00553         outb(TWDR, I2cSendData[I2cSendDataIndex++]);
00554         <span class="keywordflow">if</span>(I2cSendDataIndex &lt; I2cSendDataLength)
00555             <span class="comment">// expect ACK to data byte</span>
00556             outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00557         <span class="keywordflow">else</span>
00558             <span class="comment">// expect NACK to data byte</span>
00559             outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));
00560         <span class="keywordflow">break</span>;
00561     <span class="keywordflow">case</span> TW_ST_DATA_NACK:               <span class="comment">// 0xC0: data byte has been transmitted, NACK has been received</span>
00562     <span class="keywordflow">case</span> TW_ST_LAST_DATA:               <span class="comment">// 0xC8:</span>
00563 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00564 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00565         rprintf(<span class="stringliteral">"I2C: ST-&gt;DATA_NACK or LAST_DATA\r\n"</span>);
00566         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00567 <span class="preprocessor">        #endif</span>
00568 <span class="preprocessor"></span>        <span class="comment">// all done</span>
00569         <span class="comment">// switch to open slave</span>
00570         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00571         <span class="comment">// set state</span>
00572         I2cState = I2C_IDLE;
00573         <span class="keywordflow">break</span>;
00574 
00575     <span class="comment">// Misc</span>
00576     <span class="keywordflow">case</span> TW_NO_INFO:                    <span class="comment">// 0xF8: No relevant state information</span>
00577         <span class="comment">// do nothing</span>
00578 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00579 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00580         rprintf(<span class="stringliteral">"I2C: NO_INFO\r\n"</span>);
00581         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00582 <span class="preprocessor">        #endif</span>
00583 <span class="preprocessor"></span>        <span class="keywordflow">break</span>;
00584     <span class="keywordflow">case</span> TW_BUS_ERROR:                  <span class="comment">// 0x00: Bus error due to illegal start or stop condition</span>
00585 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00586 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00587         rprintf(<span class="stringliteral">"I2C: BUS_ERROR\r\n"</span>);
00588         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00589 <span class="preprocessor">        #endif</span>
00590 <span class="preprocessor"></span>        <span class="comment">// reset internal hardware and release bus</span>
00591         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTO)|BV(TWEA));
00592         <span class="comment">// set state</span>
00593         I2cState = I2C_IDLE;
00594         <span class="keywordflow">break</span>;
00595     }
00596 }
00597 
<a name="l00598"></a><a class="code" href="i2c_8h.html#a54">00598</a> eI2cStateType <a class="code" href="i2c_8c.html#a27">i2cGetState</a>(<span class="keywordtype">void</span>)
00599 {
00600     <span class="keywordflow">return</span> I2cState;
00601 }
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