i2c_8c-source.html

avr应用测试程序

00404     <span class="keywordflow">case</span> TW_MR_DATA_NACK:               <span class="comment">// 0x58: Data received, NACK reply issued</span>
00405 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00406 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00407         rprintf(<span class="stringliteral">"I2C: MR-&gt;DATA_NACK\r\n"</span>);
00408         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00409 <span class="preprocessor">        #endif</span>
00410 <span class="preprocessor"></span>        <span class="comment">// store final received data byte</span>
00411         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00412         <span class="comment">// continue to transmit STOP condition</span>
00413     <span class="keywordflow">case</span> TW_MR_SLA_NACK:                <span class="comment">// 0x48: Slave address not acknowledged</span>
00414     <span class="keywordflow">case</span> TW_MT_SLA_NACK:                <span class="comment">// 0x20: Slave address not acknowledged</span>
00415     <span class="keywordflow">case</span> TW_MT_DATA_NACK:               <span class="comment">// 0x30: Data not acknowledged</span>
00416 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00417 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00418         rprintf(<span class="stringliteral">"I2C: MTR-&gt;SLA_NACK or MT-&gt;DATA_NACK\r\n"</span>);
00419         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00420 <span class="preprocessor">        #endif</span>
00421 <span class="preprocessor"></span>        <span class="comment">// transmit stop condition, enable SLA ACK</span>
00422         <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00423         <span class="comment">// set state</span>
00424         I2cState = I2C_IDLE;
00425         <span class="keywordflow">break</span>;
00426     <span class="keywordflow">case</span> TW_MT_ARB_LOST:                <span class="comment">// 0x38: Bus arbitration lost</span>
00427     <span class="comment">//case TW_MR_ARB_LOST:              // 0x38: Bus arbitration lost</span>
00428 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00429 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00430         rprintf(<span class="stringliteral">"I2C: MT-&gt;ARB_LOST\r\n"</span>);
00431         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00432 <span class="preprocessor">        #endif</span>
00433 <span class="preprocessor"></span>        <span class="comment">// release bus</span>
00434         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));
00435         <span class="comment">// set state</span>
00436         I2cState = I2C_IDLE;
00437         <span class="comment">// release bus and transmit start when bus is free</span>
00438         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));</span>
00439         <span class="keywordflow">break</span>;
00440     <span class="keywordflow">case</span> TW_MR_DATA_ACK:                <span class="comment">// 0x50: Data acknowledged</span>
00441 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00442 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00443         rprintf(<span class="stringliteral">"I2C: MR-&gt;DATA_ACK\r\n"</span>);
00444         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00445 <span class="preprocessor">        #endif</span>
00446 <span class="preprocessor"></span>        <span class="comment">// store received data byte</span>
00447         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00448         <span class="comment">// fall-through to see if more bytes will be received</span>
00449     <span class="keywordflow">case</span> TW_MR_SLA_ACK:                 <span class="comment">// 0x40: Slave address acknowledged</span>
00450 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00451 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00452         rprintf(<span class="stringliteral">"I2C: MR-&gt;SLA_ACK\r\n"</span>);
00453         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00454 <span class="preprocessor">        #endif</span>
00455 <span class="preprocessor"></span>        <span class="keywordflow">if</span>(I2cReceiveDataIndex &lt; (I2cReceiveDataLength-1))
00456             <span class="comment">// data byte will be received, reply with ACK (more bytes in transfer)</span>
00457             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(TRUE);
00458         <span class="keywordflow">else</span>
00459             <span class="comment">// data byte will be received, reply with NACK (final byte in transfer)</span>
00460             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00461         <span class="keywordflow">break</span>;
00462 
00463     <span class="comment">// Slave Receiver status codes</span>
00464     <span class="keywordflow">case</span> TW_SR_SLA_ACK:                 <span class="comment">// 0x60: own SLA+W has been received, ACK has been returned</span>
00465     <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>
00466     <span class="keywordflow">case</span> TW_SR_GCALL_ACK:               <span class="comment">// 0x70:     GCA+W has been received, ACK has been returned</span>
00467     <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>
00468 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00469 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00470         rprintf(<span class="stringliteral">"I2C: SR-&gt;SLA_ACK\r\n"</span>);
00471         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00472 <span class="preprocessor">        #endif</span>
00473 <span class="preprocessor"></span>        <span class="comment">// we are being addressed as slave for writing (data will be received from master)</span>
00474         <span class="comment">// set state</span>
00475         I2cState = I2C_SLAVE_RX;
00476         <span class="comment">// prepare buffer</span>
00477         I2cReceiveDataIndex = 0;
00478         <span class="comment">// receive data byte and return ACK</span>
00479         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00480         <span class="keywordflow">break</span>;
00481     <span class="keywordflow">case</span> TW_SR_DATA_ACK:                <span class="comment">// 0x80: data byte has been received, ACK has been returned</span>
00482     <span class="keywordflow">case</span> TW_SR_GCALL_DATA_ACK:          <span class="comment">// 0x90: data byte has been received, ACK has been returned</span>
00483 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00484 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00485         rprintf(<span class="stringliteral">"I2C: SR-&gt;DATA_ACK\r\n"</span>);
00486         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00487 <span class="preprocessor">        #endif</span>
00488 <span class="preprocessor"></span>        <span class="comment">// get previously received data byte</span>
00489         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00490         <span class="comment">// check receive buffer status</span>
00491         <span class="keywordflow">if</span>(I2cReceiveDataIndex &lt; I2C_RECEIVE_DATA_BUFFER_SIZE)
00492         {
00493             <span class="comment">// receive data byte and return ACK</span>
00494             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(TRUE);
00495             <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));</span>
00496         }
00497         <span class="keywordflow">else</span>
00498         {
00499             <span class="comment">// receive data byte and return NACK</span>
00500             <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00501             <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00502         }
00503         <span class="keywordflow">break</span>;
00504     <span class="keywordflow">case</span> TW_SR_DATA_NACK:               <span class="comment">// 0x88: data byte has been received, NACK has been returned</span>
00505     <span class="keywordflow">case</span> TW_SR_GCALL_DATA_NACK:         <span class="comment">// 0x98: data byte has been received, NACK has been returned</span>
00506 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00507 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00508         rprintf(<span class="stringliteral">"I2C: SR-&gt;DATA_NACK\r\n"</span>);
00509         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00510 <span class="preprocessor">        #endif</span>
00511 <span class="preprocessor"></span>        <span class="comment">// receive data byte and return NACK</span>
00512         <a class="code" href="i2c_8c.html#a19">i2cReceiveByte</a>(FALSE);
00513         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00514         <span class="keywordflow">break</span>;
00515     <span class="keywordflow">case</span> TW_SR_STOP:                    <span class="comment">// 0xA0: STOP or REPEATED START has been received while addressed as slave</span>
00516 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00517 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00518         rprintf(<span class="stringliteral">"I2C: SR-&gt;SR_STOP\r\n"</span>);
00519         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00520 <span class="preprocessor">        #endif</span>
00521 <span class="preprocessor"></span>        <span class="comment">// switch to SR mode with SLA ACK</span>
00522         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00523         <span class="comment">// i2c receive is complete, call i2cSlaveReceive</span>
00524         <span class="keywordflow">if</span>(i2cSlaveReceive) i2cSlaveReceive(I2cReceiveDataIndex, I2cReceiveData);
00525         <span class="comment">// set state</span>
00526         I2cState = I2C_IDLE;
00527         <span class="keywordflow">break</span>;
00528 
00529     <span class="comment">// Slave Transmitter</span>
00530     <span class="keywordflow">case</span> TW_ST_SLA_ACK:                 <span class="comment">// 0xA8: own SLA+R has been received, ACK has been returned</span>
00531     <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>
00532 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00533 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00534         rprintf(<span class="stringliteral">"I2C: ST-&gt;SLA_ACK\r\n"</span>);
00535         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00536 <span class="preprocessor">        #endif</span>
00537 <span class="preprocessor"></span>        <span class="comment">// we are being addressed as slave for reading (data must be transmitted back to master)</span>
00538         <span class="comment">// set state</span>
00539         I2cState = I2C_SLAVE_TX;
00540         <span class="comment">// request data from application</span>
00541         <span class="keywordflow">if</span>(i2cSlaveTransmit) I2cSendDataLength = i2cSlaveTransmit(I2C_SEND_DATA_BUFFER_SIZE, I2cSendData);
00542         <span class="comment">// reset data index</span>
00543         I2cSendDataIndex = 0;
00544         <span class="comment">// fall-through to transmit first data byte</span>
00545     <span class="keywordflow">case</span> TW_ST_DATA_ACK:                <span class="comment">// 0xB8: data byte has been transmitted, ACK has been received</span>
00546 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00547 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00548         rprintf(<span class="stringliteral">"I2C: ST-&gt;DATA_ACK\r\n"</span>);
00549         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00550 <span class="preprocessor">        #endif</span>
00551 <span class="preprocessor"></span>        <span class="comment">// transmit data byte</span>
00552         outb(TWDR, I2cSendData[I2cSendDataIndex++]);
00553         <span class="keywordflow">if</span>(I2cSendDataIndex &lt; I2cSendDataLength)
00554             <span class="comment">// expect ACK to data byte</span>
00555             outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00556         <span class="keywordflow">else</span>
00557             <span class="comment">// expect NACK to data byte</span>
00558             outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));
00559         <span class="keywordflow">break</span>;
00560     <span class="keywordflow">case</span> TW_ST_DATA_NACK:               <span class="comment">// 0xC0: data byte has been transmitted, NACK has been received</span>
00561     <span class="keywordflow">case</span> TW_ST_LAST_DATA:               <span class="comment">// 0xC8:</span>
00562 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00563 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00564         rprintf(<span class="stringliteral">"I2C: ST-&gt;DATA_NACK or LAST_DATA\r\n"</span>);
00565         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00566 <span class="preprocessor">        #endif</span>
00567 <span class="preprocessor"></span>        <span class="comment">// all done</span>
00568         <span class="comment">// switch to open slave</span>
00569         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00570         <span class="comment">// set state</span>
00571         I2cState = I2C_IDLE;
00572         <span class="keywordflow">break</span>;
00573 
00574     <span class="comment">// Misc</span>
00575     <span class="keywordflow">case</span> TW_NO_INFO:                    <span class="comment">// 0xF8: No relevant state information</span>
00576         <span class="comment">// do nothing</span>
00577 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00578 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00579         rprintf(<span class="stringliteral">"I2C: NO_INFO\r\n"</span>);
00580         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00581 <span class="preprocessor">        #endif</span>
00582 <span class="preprocessor"></span>        <span class="keywordflow">break</span>;
00583     <span class="keywordflow">case</span> TW_BUS_ERROR:                  <span class="comment">// 0x00: Bus error due to illegal start or stop condition</span>
00584 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00585 <span class="preprocessor"></span>        <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1AddToTxBuffer);
00586         rprintf(<span class="stringliteral">"I2C: BUS_ERROR\r\n"</span>);
00587         <a class="code" href="group__rprintf.html#ga0">rprintfInit</a>(uart1SendByte);
00588 <span class="preprocessor">        #endif</span>
00589 <span class="preprocessor"></span>        <span class="comment">// reset internal hardware and release bus</span>
00590         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTO)|BV(TWEA));
00591         <span class="comment">// set state</span>
00592         I2cState = I2C_IDLE;
00593         <span class="keywordflow">break</span>;
00594     }
00595 }
00596 
<a name="l00597"></a><a class="code" href="i2c_8h.html#a54">00597</a> eI2cStateType <a class="code" href="i2c_8c.html#a27">i2cGetState</a>(<span class="keywordtype">void</span>)
00598 {
00599     <span class="keywordflow">return</span> I2cState;
00600 }
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