uart_8c-source.html

ATMEL的AVR单片机库文件

00143         {
00144             <span class="comment">// get byte from beginning of buffer</span>
00145             *rxData = <a class="code" href="buffer_8h.html#a2">bufferGetFromFront</a>(&amp;<a class="code" href="uart_8c.html#a2">uartRxBuffer</a>);
00146             <span class="keywordflow">return</span> TRUE;
00147         }
00148         <span class="keywordflow">else</span>
00149         {
00150             <span class="comment">// no data</span>
00151             <span class="keywordflow">return</span> FALSE;
00152         }
00153     }
00154     <span class="keywordflow">else</span>
00155     {
00156         <span class="comment">// no buffer</span>
00157         <span class="keywordflow">return</span> FALSE;
00158     }
00159 }
00160 <span class="comment"></span>
00161 <span class="comment">//! flush all data out of the receive buffer</span>
<a name="l00162"></a><a class="code" href="uart_8h.html#a14">00162</a> <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="uart_8c.html#a18">uartFlushReceiveBuffer</a>(<span class="keywordtype">void</span>)
00163 {
00164     <span class="comment">// flush all data from receive buffer</span>
00165     <span class="comment">//bufferFlush(&amp;uartRxBuffer);</span>
00166     <span class="comment">// same effect as above</span>
00167     <a class="code" href="uart_8c.html#a2">uartRxBuffer</a>.datalength = 0;
00168 }
00169 <span class="comment"></span>
00170 <span class="comment">//! return true if uart receive buffer is empty</span>
<a name="l00171"></a><a class="code" href="uart_8h.html#a13">00171</a> <span class="comment"></span>u08 <a class="code" href="uart_8c.html#a19">uartReceiveBufferIsEmpty</a>(<span class="keywordtype">void</span>)
00172 {
00173     <span class="keywordflow">if</span>(<a class="code" href="uart_8c.html#a2">uartRxBuffer</a>.datalength == 0)
00174     {
00175         <span class="keywordflow">return</span> TRUE;
00176     }
00177     <span class="keywordflow">else</span>
00178     {
00179         <span class="keywordflow">return</span> FALSE;
00180     }
00181 }
00182 <span class="comment"></span>
00183 <span class="comment">//! add byte to end of uart Tx buffer</span>
<a name="l00184"></a><a class="code" href="uart_8h.html#a15">00184</a> <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="uart2_8h.html#a34">uartAddToTxBuffer</a>(u08 data)
00185 {
00186     <span class="comment">// add data byte to the end of the tx buffer</span>
00187     <a class="code" href="buffer_8h.html#a5">bufferAddToEnd</a>(&amp;<a class="code" href="uart_8c.html#a3">uartTxBuffer</a>, data);
00188 }
00189 <span class="comment"></span>
00190 <span class="comment">//! start transmission of the current uart Tx buffer contents</span>
<a name="l00191"></a><a class="code" href="uart_8h.html#a16">00191</a> <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="uart_8c.html#a21">uartSendTxBuffer</a>(<span class="keywordtype">void</span>)
00192 {
00193     <span class="comment">// turn on buffered transmit</span>
00194     <a class="code" href="uart_8c.html#a1">uartBufferedTx</a> = TRUE;
00195     <span class="comment">// send the first byte to get things going by interrupts</span>
00196     <a class="code" href="uart2_8h.html#a26">uartSendByte</a>(<a class="code" href="buffer_8h.html#a2">bufferGetFromFront</a>(&amp;<a class="code" href="uart_8c.html#a3">uartTxBuffer</a>));
00197 }
00198 <span class="comment">/*</span><span class="comment"></span>
00199 <span class="comment">//! transmit nBytes from buffer out the uart</span>
00200 <span class="comment"></span>u08 uartSendBuffer(char *buffer, u16 nBytes)
00201 {
00202     register u08 first;
00203     register u16 i;
00204 
00205     // check if there's space (and that we have any bytes to send at all)
00206     if((uartTxBuffer.datalength + nBytes &lt; uartTxBuffer.size) &amp;&amp; nBytes)
00207     {
00208         // grab first character
00209         first = *buffer++;
00210         // copy user buffer to uart transmit buffer
00211         for(i = 0; i &lt; nBytes-1; i++)
00212         {
00213             // put data bytes at end of buffer
00214             bufferAddToEnd(&amp;uartTxBuffer, *buffer++);
00215         }
00216 
00217         // send the first byte to get things going by interrupts
00218         uartBufferedTx = TRUE;
00219         uartSendByte(first);
00220         // return success
00221         return TRUE;
00222     }
00223     else
00224     {
00225         // return failure
00226         return FALSE;
00227     }
00228 }
00229 */<span class="comment"></span>
00230 <span class="comment">//! UART Transmit Complete Interrupt Handler</span>
<a name="l00231"></a><a class="code" href="uart_8c.html#a22">00231</a> <span class="comment"></span>UART_INTERRUPT_HANDLER(SIG_UART_TRANS)
00232 {
00233     <span class="comment">// check if buffered tx is enabled</span>
00234     <span class="keywordflow">if</span>(<a class="code" href="uart_8c.html#a1">uartBufferedTx</a>)
00235     {
00236         <span class="comment">// check if there's data left in the buffer</span>
00237         <span class="keywordflow">if</span>(<a class="code" href="uart_8c.html#a3">uartTxBuffer</a>.datalength)
00238         {
00239             <span class="comment">// send byte from top of buffer</span>
00240             outp( <a class="code" href="buffer_8h.html#a2">bufferGetFromFront</a>(&amp;<a class="code" href="uart_8c.html#a3">uartTxBuffer</a>), UDR );
00241         }
00242         <span class="keywordflow">else</span>
00243         {
00244             <span class="comment">// no data left</span>
00245             <a class="code" href="uart_8c.html#a1">uartBufferedTx</a> = FALSE;
00246             <span class="comment">// return to ready state</span>
00247             <a class="code" href="uart_8c.html#a0">uartReadyTx</a> = TRUE;
00248         }
00249     }
00250     <span class="keywordflow">else</span>
00251     {
00252         <span class="comment">// we're using single-byte tx mode</span>
00253         <span class="comment">// indicate transmit complete, back to ready</span>
00254         <a class="code" href="uart_8c.html#a0">uartReadyTx</a> = TRUE;
00255     }
00256 }
00257 <span class="comment"></span>
00258 <span class="comment">//! UART Receive Complete Interrupt Handler</span>
<a name="l00259"></a><a class="code" href="uart_8c.html#a23">00259</a> <span class="comment"></span>UART_INTERRUPT_HANDLER(SIG_UART_RECV)
00260 {
00261     u08 c;
00262     
00263     <span class="comment">// get received char</span>
00264     c = inp(UDR);
00265 
00266     <span class="comment">// if there's a user function to handle this receive event</span>
00267     <span class="keywordflow">if</span>(UartRxFunc)
00268     {
00269         <span class="comment">// call it and pass the received data</span>
00270         UartRxFunc(c);
00271     }
00272     <span class="keywordflow">else</span>
00273     {
00274         <span class="comment">// otherwise do default processing</span>
00275         <span class="comment">// put received char in buffer</span>
00276         <span class="comment">// check if there's space</span>
00277         <span class="keywordflow">if</span>( !<a class="code" href="buffer_8h.html#a5">bufferAddToEnd</a>(&amp;<a class="code" href="uart_8c.html#a2">uartRxBuffer</a>, c) )
00278         {
00279             <span class="comment">// no space in buffer</span>
00280             <span class="comment">// count overflow</span>
00281             <a class="code" href="uart_8c.html#a4">uartRxOverflow</a>++;
00282         }
00283     }
00284 }
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