uart_8c-source.html

单片机的软件

00143         {
00144             <span class="comment">// get byte from beginning of buffer</span>
00145             *rxData = <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(&amp;uartRxBuffer);
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 
00161 <span class="comment">// flush all data out of the receive buffer</span>
<a name="l00162"></a><a class="code" href="group__uart.html#ga10">00162</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga10">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     uartRxBuffer.<a class="code" href="structstruct__cBuffer.html#o2">datalength</a> = 0;
00168 }
00169 
00170 <span class="comment">// return true if uart receive buffer is empty</span>
<a name="l00171"></a><a class="code" href="group__uart.html#ga9">00171</a> u08 <a class="code" href="group__uart.html#ga9">uartReceiveBufferIsEmpty</a>(<span class="keywordtype">void</span>)
00172 {
00173     <span class="keywordflow">if</span>(uartRxBuffer.<a class="code" href="structstruct__cBuffer.html#o2">datalength</a> == 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 
00183 <span class="comment">// add byte to end of uart Tx buffer</span>
<a name="l00184"></a><a class="code" href="group__uart.html#ga11">00184</a> u08 <a class="code" href="group__uart.html#ga11">uartAddToTxBuffer</a>(u08 data)
00185 {
00186     <span class="comment">// add data byte to the end of the tx buffer</span>
00187     <span class="keywordflow">return</span> <a class="code" href="group__buffer.html#ga5">bufferAddToEnd</a>(&amp;uartTxBuffer, data);
00188 }
00189 
00190 <span class="comment">// start transmission of the current uart Tx buffer contents</span>
<a name="l00191"></a><a class="code" href="group__uart.html#ga12">00191</a> <span class="keywordtype">void</span> <a class="code" href="group__uart.html#ga12">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="group__uart.html#ga6">uartSendByte</a>(<a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(&amp;uartTxBuffer));
00197 }
00198 <span class="comment">/*</span>
00199 <span class="comment">// transmit nBytes from buffer out the uart</span>
00200 <span class="comment">u08 uartSendBuffer(char *buffer, u16 nBytes)</span>
00201 <span class="comment">{</span>
00202 <span class="comment">    register u08 first;</span>
00203 <span class="comment">    register u16 i;</span>
00204 <span class="comment"></span>
00205 <span class="comment">    // check if there's space (and that we have any bytes to send at all)</span>
00206 <span class="comment">    if((uartTxBuffer.datalength + nBytes &lt; uartTxBuffer.size) &amp;&amp; nBytes)</span>
00207 <span class="comment">    {</span>
00208 <span class="comment">        // grab first character</span>
00209 <span class="comment">        first = *buffer++;</span>
00210 <span class="comment">        // copy user buffer to uart transmit buffer</span>
00211 <span class="comment">        for(i = 0; i &lt; nBytes-1; i++)</span>
00212 <span class="comment">        {</span>
00213 <span class="comment">            // put data bytes at end of buffer</span>
00214 <span class="comment">            bufferAddToEnd(&amp;uartTxBuffer, *buffer++);</span>
00215 <span class="comment">        }</span>
00216 <span class="comment"></span>
00217 <span class="comment">        // send the first byte to get things going by interrupts</span>
00218 <span class="comment">        uartBufferedTx = TRUE;</span>
00219 <span class="comment">        uartSendByte(first);</span>
00220 <span class="comment">        // return success</span>
00221 <span class="comment">        return TRUE;</span>
00222 <span class="comment">    }</span>
00223 <span class="comment">    else</span>
00224 <span class="comment">    {</span>
00225 <span class="comment">        // return failure</span>
00226 <span class="comment">        return FALSE;</span>
00227 <span class="comment">    }</span>
00228 <span class="comment">}</span>
00229 <span class="comment">*/</span>
00230 <span class="comment">// UART Transmit Complete Interrupt Handler</span>
00231 <a class="code" href="group__uart.html#ga17">UART_INTERRUPT_HANDLER</a>(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>(uartTxBuffer.<a class="code" href="structstruct__cBuffer.html#o2">datalength</a>)
00238         {
00239             <span class="comment">// send byte from top of buffer</span>
00240             outb(UDR, <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(&amp;uartTxBuffer));
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 
00258 <span class="comment">// UART Receive Complete Interrupt Handler</span>
00259 <a class="code" href="group__uart.html#ga17">UART_INTERRUPT_HANDLER</a>(SIG_UART_RECV)
00260 {
00261     u08 c;
00262     
00263     <span class="comment">// get received char</span>
00264     c = inb(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="group__buffer.html#ga5">bufferAddToEnd</a>(&amp;uartRxBuffer, 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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