i2c_8c-source.html

ATMEL的AVR单片机库文件

00428         {
00429             <span class="comment">// send data</span>
00430             <a class="code" href="i2c_8h.html#a18">i2cSendByte</a>( I2cSendData[I2cSendDataIndex++] );
00431         }
00432         <span class="keywordflow">else</span>
00433         {
00434             <span class="comment">// transmit stop condition, enable SLA ACK</span>
00435             <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00436             <span class="comment">// set state</span>
00437             I2cState = I2C_IDLE;
00438         }
00439         <span class="keywordflow">break</span>;
00440     <span class="keywordflow">case</span> TW_MR_DATA_NACK:               <span class="comment">// 0x58: Data received, NACK reply issued</span>
00441 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00442 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00443         rprintf(<span class="stringliteral">"I2C: MR-&gt;DATA_NACK\r\n"</span>);
00444         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00445 <span class="preprocessor">        #endif</span>
00446 <span class="preprocessor"></span>        <span class="comment">// store final received data byte</span>
00447         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00448         <span class="comment">// continue to transmit STOP condition</span>
00449     <span class="keywordflow">case</span> TW_MR_SLA_NACK:                <span class="comment">// 0x48: Slave address not acknowledged</span>
00450     <span class="keywordflow">case</span> TW_MT_SLA_NACK:                <span class="comment">// 0x20: Slave address not acknowledged</span>
00451     <span class="keywordflow">case</span> TW_MT_DATA_NACK:               <span class="comment">// 0x30: Data not acknowledged</span>
00452 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00453 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00454         rprintf(<span class="stringliteral">"I2C: MTR-&gt;SLA_NACK or MT-&gt;DATA_NACK\r\n"</span>);
00455         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00456 <span class="preprocessor">        #endif</span>
00457 <span class="preprocessor"></span>        <span class="comment">// transmit stop condition, enable SLA ACK</span>
00458         <a class="code" href="i2c_8c.html#a16">i2cSendStop</a>();
00459         <span class="comment">// set state</span>
00460         I2cState = I2C_IDLE;
00461         <span class="keywordflow">break</span>;
00462     <span class="keywordflow">case</span> TW_MT_ARB_LOST:                <span class="comment">// 0x38: Bus arbitration lost</span>
00463     <span class="comment">//case TW_MR_ARB_LOST:              // 0x38: Bus arbitration lost</span>
00464 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00465 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00466         rprintf(<span class="stringliteral">"I2C: MT-&gt;ARB_LOST\r\n"</span>);
00467         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00468 <span class="preprocessor">        #endif</span>
00469 <span class="preprocessor"></span>        <span class="comment">// release bus</span>
00470         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));
00471         <span class="comment">// set state</span>
00472         I2cState = I2C_IDLE;
00473         <span class="comment">// release bus and transmit start when bus is free</span>
00474         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTA));</span>
00475         <span class="keywordflow">break</span>;
00476     <span class="keywordflow">case</span> TW_MR_DATA_ACK:                <span class="comment">// 0x50: Data acknowledged</span>
00477 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00478 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00479         rprintf(<span class="stringliteral">"I2C: MR-&gt;DATA_ACK\r\n"</span>);
00480         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00481 <span class="preprocessor">        #endif</span>
00482 <span class="preprocessor"></span>        <span class="comment">// store received data byte</span>
00483         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00484         <span class="comment">// fall-through to see if more bytes will be received</span>
00485     <span class="keywordflow">case</span> TW_MR_SLA_ACK:                 <span class="comment">// 0x40: Slave address acknowledged</span>
00486 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00487 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00488         rprintf(<span class="stringliteral">"I2C: MR-&gt;SLA_ACK\r\n"</span>);
00489         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00490 <span class="preprocessor">        #endif</span>
00491 <span class="preprocessor"></span>        <span class="keywordflow">if</span>(I2cReceiveDataIndex &lt; (I2cReceiveDataLength-1))
00492             <span class="comment">// data byte will be received, reply with ACK (more bytes in transfer)</span>
00493             <a class="code" href="i2c_8h.html#a19">i2cReceiveByte</a>(TRUE);
00494         <span class="keywordflow">else</span>
00495             <span class="comment">// data byte will be received, reply with NACK (final byte in transfer)</span>
00496             <a class="code" href="i2c_8h.html#a19">i2cReceiveByte</a>(FALSE);
00497         <span class="keywordflow">break</span>;
00498 
00499     <span class="comment">// Slave Receiver status codes</span>
00500     <span class="keywordflow">case</span> TW_SR_SLA_ACK:                 <span class="comment">// 0x60: own SLA+W has been received, ACK has been returned</span>
00501     <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>
00502     <span class="keywordflow">case</span> TW_SR_GCALL_ACK:               <span class="comment">// 0x70:     GCA+W has been received, ACK has been returned</span>
00503     <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>
00504 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00505 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00506         rprintf(<span class="stringliteral">"I2C: SR-&gt;SLA_ACK\r\n"</span>);
00507         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00508 <span class="preprocessor">        #endif</span>
00509 <span class="preprocessor"></span>        <span class="comment">// we are being addressed as slave for writing (data will be received from master)</span>
00510         <span class="comment">// set state</span>
00511         I2cState = I2C_SLAVE_RX;
00512         <span class="comment">// prepare buffer</span>
00513         I2cReceiveDataIndex = 0;
00514         <span class="comment">// receive data byte and return ACK</span>
00515         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00516         <span class="keywordflow">break</span>;
00517     <span class="keywordflow">case</span> TW_SR_DATA_ACK:                <span class="comment">// 0x80: data byte has been received, ACK has been returned</span>
00518     <span class="keywordflow">case</span> TW_SR_GCALL_DATA_ACK:          <span class="comment">// 0x90: data byte has been received, ACK has been returned</span>
00519 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00520 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00521         rprintf(<span class="stringliteral">"I2C: SR-&gt;DATA_ACK\r\n"</span>);
00522         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00523 <span class="preprocessor">        #endif</span>
00524 <span class="preprocessor"></span>        <span class="comment">// get previously received data byte</span>
00525         I2cReceiveData[I2cReceiveDataIndex++] = inb(TWDR);
00526         <span class="comment">// check receive buffer status</span>
00527         <span class="keywordflow">if</span>(I2cReceiveDataIndex &lt; I2C_RECEIVE_DATA_BUFFER_SIZE)
00528         {
00529             <span class="comment">// receive data byte and return ACK</span>
00530             <a class="code" href="i2c_8h.html#a19">i2cReceiveByte</a>(TRUE);
00531             <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));</span>
00532         }
00533         <span class="keywordflow">else</span>
00534         {
00535             <span class="comment">// receive data byte and return NACK</span>
00536             <a class="code" href="i2c_8h.html#a19">i2cReceiveByte</a>(FALSE);
00537             <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00538         }
00539         <span class="keywordflow">break</span>;
00540     <span class="keywordflow">case</span> TW_SR_DATA_NACK:               <span class="comment">// 0x88: data byte has been received, NACK has been returned</span>
00541     <span class="keywordflow">case</span> TW_SR_GCALL_DATA_NACK:         <span class="comment">// 0x98: data byte has been received, NACK has been returned</span>
00542 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00543 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00544         rprintf(<span class="stringliteral">"I2C: SR-&gt;DATA_NACK\r\n"</span>);
00545         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00546 <span class="preprocessor">        #endif</span>
00547 <span class="preprocessor"></span>        <span class="comment">// receive data byte and return NACK</span>
00548         <a class="code" href="i2c_8h.html#a19">i2cReceiveByte</a>(FALSE);
00549         <span class="comment">//outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));</span>
00550         <span class="keywordflow">break</span>;
00551     <span class="keywordflow">case</span> TW_SR_STOP:                    <span class="comment">// 0xA0: STOP or REPEATED START has been received while addressed as slave</span>
00552 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00553 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00554         rprintf(<span class="stringliteral">"I2C: SR-&gt;SR_STOP\r\n"</span>);
00555         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00556 <span class="preprocessor">        #endif</span>
00557 <span class="preprocessor"></span>        <span class="comment">// switch to SR mode with SLA ACK</span>
00558         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00559         <span class="comment">// i2c receive is complete, call i2cSlaveReceive</span>
00560         <span class="keywordflow">if</span>(i2cSlaveReceive) i2cSlaveReceive(I2cReceiveDataIndex, I2cReceiveData);
00561         <span class="comment">// set state</span>
00562         I2cState = I2C_IDLE;
00563         <span class="keywordflow">break</span>;
00564 
00565     <span class="comment">// Slave Transmitter</span>
00566     <span class="keywordflow">case</span> TW_ST_SLA_ACK:                 <span class="comment">// 0xA8: own SLA+R has been received, ACK has been returned</span>
00567     <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>
00568 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00569 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00570         rprintf(<span class="stringliteral">"I2C: ST-&gt;SLA_ACK\r\n"</span>);
00571         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00572 <span class="preprocessor">        #endif</span>
00573 <span class="preprocessor"></span>        <span class="comment">// we are being addressed as slave for reading (data must be transmitted back to master)</span>
00574         <span class="comment">// set state</span>
00575         I2cState = I2C_SLAVE_TX;
00576         <span class="comment">// request data from application</span>
00577         <span class="keywordflow">if</span>(i2cSlaveTransmit) I2cSendDataLength = i2cSlaveTransmit(I2C_SEND_DATA_BUFFER_SIZE, I2cSendData);
00578         <span class="comment">// reset data index</span>
00579         I2cSendDataIndex = 0;
00580         <span class="comment">// fall-through to transmit first data byte</span>
00581     <span class="keywordflow">case</span> TW_ST_DATA_ACK:                <span class="comment">// 0xB8: data byte has been transmitted, ACK has been received</span>
00582 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00583 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00584         rprintf(<span class="stringliteral">"I2C: ST-&gt;DATA_ACK\r\n"</span>);
00585         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00586 <span class="preprocessor">        #endif</span>
00587 <span class="preprocessor"></span>        <span class="comment">// transmit data byte</span>
00588         outb(TWDR, I2cSendData[I2cSendDataIndex++]);
00589         <span class="keywordflow">if</span>(I2cSendDataIndex &lt; I2cSendDataLength)
00590             <span class="comment">// expect ACK to data byte</span>
00591             outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00592         <span class="keywordflow">else</span>
00593             <span class="comment">// expect NACK to data byte</span>
00594             outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT));
00595         <span class="keywordflow">break</span>;
00596     <span class="keywordflow">case</span> TW_ST_DATA_NACK:               <span class="comment">// 0xC0: data byte has been transmitted, NACK has been received</span>
00597     <span class="keywordflow">case</span> TW_ST_LAST_DATA:               <span class="comment">// 0xC8:</span>
00598 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00599 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00600         rprintf(<span class="stringliteral">"I2C: ST-&gt;DATA_NACK or LAST_DATA\r\n"</span>);
00601         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00602 <span class="preprocessor">        #endif</span>
00603 <span class="preprocessor"></span>        <span class="comment">// all done</span>
00604         <span class="comment">// switch to open slave</span>
00605         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
00606         <span class="comment">// set state</span>
00607         I2cState = I2C_IDLE;
00608         <span class="keywordflow">break</span>;
00609 
00610     <span class="comment">// Misc</span>
00611     <span class="keywordflow">case</span> TW_NO_INFO:                    <span class="comment">// 0xF8: No relevant state information</span>
00612         <span class="comment">// do nothing</span>
00613 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00614 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00615         rprintf(<span class="stringliteral">"I2C: NO_INFO\r\n"</span>);
00616         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00617 <span class="preprocessor">        #endif</span>
00618 <span class="preprocessor"></span>        <span class="keywordflow">break</span>;
00619     <span class="keywordflow">case</span> TW_BUS_ERROR:                  <span class="comment">// 0x00: Bus error due to illegal start or stop condition</span>
00620 <span class="preprocessor">        #ifdef I2C_DEBUG</span>
00621 <span class="preprocessor"></span>        <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1AddToTxBuffer);
00622         rprintf(<span class="stringliteral">"I2C: BUS_ERROR\r\n"</span>);
00623         <a class="code" href="rprintf_8h.html#a6">rprintfInit</a>(uart1SendByte);
00624 <span class="preprocessor">        #endif</span>
00625 <span class="preprocessor"></span>        <span class="comment">// reset internal hardware and release bus</span>
00626         outb(TWCR, (inb(TWCR)&amp;TWCR_CMD_MASK)|BV(TWINT)|BV(TWSTO)|BV(TWEA));
00627         <span class="comment">// set state</span>
00628         I2cState = I2C_IDLE;
00629         <span class="keywordflow">break</span>;
00630     }
00631 }
00632 
<a name="l00633"></a><a class="code" href="i2c_8h.html#a26">00633</a> eI2cStateType <a class="code" href="i2c_8c.html#a27">i2cGetState</a>(<span class="keywordtype">void</span>)
00634 {
00635     <span class="keywordflow">return</span> I2cState;
00636 }
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