X-Git-Url: https://oss.titaniummirror.com/gitweb/?p=tinyos-2.x.git;a=blobdiff_plain;f=tos%2Fchips%2Fcc2420%2Freceive%2FCC2420ReceiveP.nc;h=5bd4e852e54eb383c85a67d7be24b94a80e15a47;hp=30a421914b9da6a819bfe2e3db99dc92b7ba03c2;hb=aa7578fd1472c62c1d22d0801fe0f55b36093bdf;hpb=c3864fde9bec0c02c0c6b4221ddde0801a82c980

diff --git a/tos/chips/cc2420/receive/CC2420ReceiveP.nc b/tos/chips/cc2420/receive/CC2420ReceiveP.nc
index 30a42191..5bd4e852 100644
--- a/tos/chips/cc2420/receive/CC2420ReceiveP.nc
+++ b/tos/chips/cc2420/receive/CC2420ReceiveP.nc
@@ -126,6 +126,10 @@ implementation {
       reset_state();
       m_state = S_STARTED;
       atomic receivingPacket = FALSE;
+      /* Note:
+         We use the falling edge because the FIFOP polarity is reversed. 
+         This is done in CC2420Power.startOscillator from CC2420ControlP.nc.
+       */
       call InterruptFIFOP.enableFallingEdge();
     }
     return SUCCESS;
@@ -281,16 +285,25 @@ implementation {
         call SpiResource.release();
       }
       
-      if ( m_timestamp_size ) {
-        if ( rxFrameLength > 10 ) {
-          call PacketTimeStamp.set(m_p_rx_buf, m_timestamp_queue[ m_timestamp_head ]);
+      //new packet is buffered up, or we don't have timestamp in fifo, or ack
+      if ( ( m_missed_packets && call FIFO.get() ) || !call FIFOP.get()
+            || !m_timestamp_size
+            || rxFrameLength <= 10) {
+        call PacketTimeStamp.clear(m_p_rx_buf);
+      }
+      else {
+          if (m_timestamp_size==1)
+            call PacketTimeStamp.set(m_p_rx_buf, m_timestamp_queue[ m_timestamp_head ]);
           m_timestamp_head = ( m_timestamp_head + 1 ) % TIMESTAMP_QUEUE_SIZE;
           m_timestamp_size--;
-        }
-      } else {
-        call PacketTimeStamp.clear(m_p_rx_buf);
+
+          if (m_timestamp_size>0) {
+            call PacketTimeStamp.clear(m_p_rx_buf);
+            m_timestamp_head = 0;
+            m_timestamp_size = 0;
+          }
       }
-      
+
       // We may have received an ack that should be processed by Transmit
       // buf[rxFrameLength] >> 7 checks the CRC
       if ( ( buf[ rxFrameLength ] >> 7 ) && rx_buf ) {