patches13/0010-docu.patch

git-svn-id: http://svn.eurecom.fr/openair4G/trunk@7056 818b1a75-f10b-46b9-bf7c-635c3b92a50f

targets/ARCH/COMMON/common_lib.h

@@ -115,10 +115,17 @@ struct openair0_device_t {
    * use flags = 1 to send as timestamp specfied*/
   void (*trx_write_func)(openair0_device *device, openair0_timestamp timestamp, void **buff, int nsamps, int cc, int flags);
 
-  /* Read 'nsamps' samples from each channel to buffers. buff[0] is the array for
+  /*! \brief Receive samples from hardware.
+   * Read \ref nsamps samples from each channel to buffers. buff[0] is the array for
    * the first channel. *ptimestamp is the time at which the first sample
    * was received.
-   * Return the number of sample read */
+   * \param device the hardware to use
+   * \param[out] ptimestamp the time at which the first sample was received.
+   * \param[out] An array of pointers to buffers for received samples. The buffers must be large enough to hold the number of samples \ref nsamps.
+   * \param nsamps Number of samples. One sample is 2 byte I + 2 byte Q => 4 byte.
+   * \param cc Number of channels. If cc == 1, only buff[0] is filled with samples.
+   * \returns the number of sample read
+   */
   int (*trx_read_func)(openair0_device *device, openair0_timestamp *ptimestamp, void **buff, int nsamps,int cc);
 
   /* Terminate operation of the transceiver -- free all associated resources */

targets/ARCH/USRP/USERSPACE/LIB/usrp_lib.cpp

@@ -153,12 +153,14 @@ static int trx_usrp_read(openair0_device *device, openair0_timestamp *ptimestamp
   int samples_received=0,i;
   
   if (cc>1) {
+    // receive multiple channels (e.g. RF A and RF B)
     std::vector<void *> buff_ptrs;
     for (int i=0;i<cc;i++) buff_ptrs.push_back(buff[i]);
     samples_received = s->rx_stream->recv(buff_ptrs, nsamps, s->rx_md);
-  }
-  else
+  } else {
+    // receive a single channel (e.g. from connector RF A)
     samples_received = s->rx_stream->recv(buff[0], nsamps, s->rx_md);
+  }
 
   if (samples_received < nsamps) {
     printf("[recv] received %d samples out of %d\n",samples_received,nsamps);