0 Replies Latest reply on Nov 7, 2012 11:32 AM by devendra.rai

    RCCE_Send & RCCE_Recv Times

    devendra.rai

      Hello,

       

      I am observing timing behaviour on the SCC (baremetal) that I need help understanding:

       

      A process on Core 14 sends a message to Core 28, Core 18, Core 02, Core 40 (in this order). The message is 16 bytes long.

       

      Here is what I observe:

       

      (1) Core 02 gets the message in ~2300 clock cycles;

      (2). Core 18 gets the message in ~4600 clocks cycles;

      (3). Core 28 gets the message in ~6900 clock cycles;

      (4). Core 40 gets the message in ~2100 clocks cycles;

       

      I wonder why Core 28 takes so long to receive the message, and I would expect that it would receive the message *earlier* than Core 40 (XY routing).

       

      I am assuming it has something to do with wavefront arbitration at the router. I found a document that talks about it, but am still confused. 

       

      Can anyone see what is going on?

       

      Thanks.

       

       

      Devendra